24' Fiberform - Rotten Stringers/Transom

[Ehdrian]

Hello Everyone,

I have been reading this site for while now and have learned allot about stringers and transoms. I was wondering if I could get some tips for my specific issue as I am very new to boat repair. :confused:

This boat is a 1977 24' Fiberform Cabin cruiser. It has four stringers running from the transom to the bow. The engines rest on the two center stringers. The stringers look like regular 2"x10" fir boards grafted at the top and bottom to fit he hull and furniture (galley/helm/motor mounts etc..). The twin engines are OMC 140's with OMC stringer 400 drives.

Bad news: All of the stringers are rotten and there is rot in the transom.

I would like to replace the stringers without removing the engines or the transom the first time through.

Has anyone replaced stringers without removing the engines? On this type of boat? How?

Can I just cap the end of the stringer with fiberglass (no wood touching wood) at the transom and replace the transom later so the new stringers are not affected by the transom repair.

What should I use underneath the stringer to keep it from touching the bottom of the boat?

Is there REALLY 'pour in' foam that could be used in place of a stringer?

What are the best tools for cutting out thick fiberglass around a stringer? Right now I'm using a side grinder.

Thank you very much to all those that help! :D

-=//-\drian Thompson=-

[marshmat]

Bad news: All of the stringers are rotten and there is rot in the transom. I would like to replace the stringers without removing the engines or the transom the first time through
Ouch.
I see two ways of doing this. The first is to leave the motors in, glass over the rot, pretend nothing's wrong, and wait for an engine to slam right through the bottom of the hull when you come off a wave.
The second is to take out the motors and drives, support the hull very well from outside, take out ALL the rotten and/or damaged wood, and rebuild them properly the way they should have been in the first place.
Can I just cap the end of the stringer with fiberglass (no wood touching wood) at the transom and replace the transom later so the new stringers are not affected by the transom repair. The stringers really should be glassed to the transom, with some very solid bracing- there's a lot of stress here from those drives. Better to do it all at once.
Is there REALLY 'pour in' foam that could be used in place of a stringer? I'm afraid I'm not aware of any such product that will hold up to the job structurally, and especially in terms of water damage and deterioration.
What are the best tools for cutting out thick fiberglass around a stringer? Right now I'm using a side grinder. The angle grinder you're using is a popular one and it works. Fibreglass is bloody hard to cut and destroys high-grade saw blades like they were made of plastic.

[jimslade]

Do it right, if you don't you will regret it!

[Ehdrian]

Ok. I have ripped out one mush stringer and exposed the other three which have 1/16" surface rot on one side and about a 1/4" rot on the other where it touched the bulkhead. The transom needs to be replaced, which I will do from the inside behind the engines.

I have heard of a product called CPES which might be used to 're-thicken' the stringer where I cut away the 1/16 + 1/4 using sawdust or fiberglass dust as a filler. It is about a 3 1/2ft stretch where this needs to be done. The stringer is bone dry in the middle after a core sample.

Has anyone fixed a hole 1/4 inch deep and three ft long with this stuff? It is recommended?

Thanks!

[eyes]

I agree with theses guys. Do it right, do it once.
You can check this site, http://classicmako.com , they have a lot of projects going on and finished. Check on the process (pics) and come back post pics of your progres and ask the experts here to guide you trough the process.
This is a awesome site with a lot of knowledge inside.

[eyes]

You better think about getting some lifevests if you decide to just repair part of it.

[Ehdrian]

Ok. What should I use or the stringers?

Cedar, Spruce, Douglas Fir or 2x Plywood laminated together?

Should I use treated plywood or marine plywood for the transom, decks and bulkheads? Does the epoxy bond well with these? I would like to avoid marine plywood as it is expensive.

EDIT: Is it OK to use a urethane layup or must I use epoxy? I don't know what the hull is made of.... If the hull is epoxy based, will this compromise the structure of the boat?

Thanks!

[tja]

The hull is made with polyester resin. Stick with that. It's easier to work with and you won't like the cost of epoxy. For plywood i'd look into Greenwood products XL panels. Alot of good boat yards and manufacturers use it and will sell you what you need. It is guarenteed not to rot or delaminate for life or they will replace it including lobor. If it's worth doing it's worth doing right. Before you tear out too much sit down out make a plan and don't exspect it to go according to what time you think it should take. It will most likely two to three times longer. Good luck. Tom.

[PAR]

There isn't any wonder goo in a can (Smith's CPES included) that will restore rotted sections of wood. Small, well isolated pockets of rot can be "treated" with epoxy (CPES is epoxy), which will harden the general area, but larger voids, clearly deformed or rotted sections of wood must be removed and an affective repair made.

Your repair area sounds like a pitch pocket that has rotted away or moisture got trapped under a delaminated sheathing or tabbing (most likely). This has reduced the load bearing ability of the stringer. You also very likely have rot in other, internal areas, that you haven't found or can't see. You already have one spent stringer and three others in need of repair. Do you want to perform a Dutchman kind of thing or would you prefer not to have to gut the boat again?

Fiberform was one of the many low end boat builders, that went belly up during the glut years of the late 70's. They built as many as they could, as quickly and inexpensively as possible. This manufacturing method doesn't lead to long lived yachts, but does show a profit in the short term (until your company reputation takes a whipping). This was the common thinking and manufacturing practices of the era, in many of the low end production companies.

Their boats were original pretty heavily laid up, but the chopper gun method, resin choices and poor craftsmanship caused repair, durability and resale value issues that killed the company. Fiberform ceased to be in 1982, when Bayliner bought all, part or it's inventory and equipment. It had been in trouble for several years prior. Bayliner refuses to discuss it's Fiberform purchase.

Your boat is experiencing some of these corporate choices. Poor wet out under the stringers, less then satisfactory tabbing, insufficient wood saturation and sheathing to prevent moisture ingress, etc. have worked their magic and caused some problems.

Now for the good news, your boat is repairable, though you have to ask yourself if it's worth the cost, effort and time. This is a tough decision, but a necessary one. Transom replacement, stringer and sole replacement, so far as I understand it now. That's a lot of work on an old war horse, like yours. Keys to answering this question are: do the engines run and have reasonably low hours, is the hull shell distorted from being on the trailer or having damaged structural pieces, good electrics, plumbing, electronics, etc. If you can tick off most on the list of things that make the boat work, then you have a good candidate. If the engines are blowing oil and smoke, the electrical looks like spaghetti, the plumbing isn't reliable, the electronics include a Loran and the transmissions grind going into reverse (when they do) then maybe you should salvage what you can and find another boat to work with.

Polyester is the poorest choice for this repair. It's used in the industry (and being phased out, guess why) because it's cheaper then the better products. Vinylester is a better choice with epoxy being the best route to go, in these types of repairs. The polyester failed once already, you can use this resin if you want, but you probably have the same problems again in the future.

There are many transom and stringer replacement threads, on this web sight and a search will offer much information, for you to cruise through.

If you've decided to save this boat, then gut it. Remove the engines, transmissions, tanks, etc. Anything in the way, so you can get in there with some tools to cut back tabbing and bad stringers or transom. A reciprocating saw (my favorite), angle grinder, big buffer with cutting wheel, Roto-Zip, chisel and a jig saw are typical, heavy stock removal tools. Cut out the suspected areas of rot, insuring that you've gotten back into good wood, by a fair distance (at least a foot in each direction, with exception of the transom which should have all it's wood removed). Grind all exposed 'glass clean with 36 grit (or less), so you have a good "tooth" for the repair to bond to. Cut your repair pieces to fit snuggly, then give them three coats of unthickened resin, which will seal them when cured. Then bond the repairs into the boat, using plenty of fabric. Don't skimp on the protective coatings and fabrics, this is why the pieces failed in the first place.

[TerryKing]

..(snip)..Should I use treated plywood or marine plywood for the transom, decks and bulkheads? Does the epoxy bond well with these? I would like to avoid marine plywood as it is expensive.

For some info on treated plywood, adhesion etc., see:
http://www.boatdesign.net/wiki/MaterialsForBoatbuilding#PRESERVING_WOOD_AGAINST_DETERIORATION
(This Wiki section is incomplete, but some of the questions are addressed there).

I would want treated wood in a transom; they always seem to get water intrusion sooner or later.. I used well-dried 3/4 inch Pressure-Treated plywood in a transom replacement 6 years ago, and everything bonded well.

[Ehdrian]

Thank you for the replies!

Engines:
Run smooth and quiet with no obvious mechanical issues.

Outdrives:
Needs new impellers and fluid/seal change - knuckles might need changing soon. Other than that they work as intended (forward and reverse). I need to replace the electric motor that lifts the port side outdrive. I'm going to hire a professional marine mechanic to remove them for the transom rebuild, but I'm going to refurbish the outdrives myself after the service manual comes in the mail.

Electronics:
All works, just need some re-connecting in places. The wires are bound and strung nicely from the helm to the starboard side engine. I need to put in a new hydraulic pump for one trim tab (already purchaced).

Hull:
No sags, needs to dry out, gel coat is chipped in places, but in excellent condition. There was a 'bulge' on the rear-left side beside the engine that was cut out and fixed already - because it was sitting on dry dock (this is how the rot was found). There are allot of leaks around the hatch and windows, but calking will fix that. I also need to build the engine covers (doghouse) from scratch.

Plumbing:
Fresh water pump works and I have a honeypot.

I think all I have left to do is replace all the wooden parts. :D

Here is what I am thinking so far, based on the feed back you all have nicely given me:

Douglas Fir Stringers
Exterior grade ply for the bulkheads and decking saturated in thin resin
Marine grade for the transom
Resin: I'll look into the Vinylester.

I have a question about the fiberglass sheets though:

There is a product that has woven roving and mat stiched together. Will this save me some build time, or am I better off just laminating these layers separatly? How thick should I build the lamination around he stringers?


Thanks again!! :D

[marshmat]

There is a product that has woven roving and mat stiched together. Will this save me some build time, or am I better off just laminating these layers separatly? I suspect this would be a pain in the ass to wet out properly. It's a lot easier to get several thin layers to wet out nicely without bubbles, than to get one really heavy layer to do the same. In my experience, two layers of 300 gsm cloth only takes about 20% more time than one layer of 600 gsm, and ends up with much less entrapped air bubbles. Plus the thinner layers handle corners and compound curves a lot better.

It sounds like you're pretty confident that the mechanical and electrical gear is in reasonable working order, and you seem eager to take on a project. So I say go for it. Just be careful not to delude yourself into believing it will be easy, cheap, or quick. Oh, and if you insist on using poly/vinyl ester resins, buy yourself a damn good fume mask because both stink to high heaven. Epoxy's much more expensive but is a lot stronger, easier to use, and more durable, not to mention less nasty to work with.

[Ehdrian]

Alright! I'll post pictures as I go... if I can borrow a camera off of a friend.

[PAR]

Combi mat will not offer much for you if using epoxy, if using vinylester it can. The mat is a bulking material and adds very little strength to the laminate. It's added to act as a core of sorts, separating the inner and outer cloth layers, which provides a strong laminate. If you can do the laminate in one shot, then the combi material will be helpful, but if you will be putting layers on in succession, then it isn't much help. As a beginner, you're better off not trying to do too much at once, so skip the combi mat and stick with cloth.

For amateur repairs like this I always recommend epoxy. As Matt mentioned, it is easier to work with, doesn't have the smell (still protect yourself, especially when in enclosed areas) and is a lot stronger. My reasoning for this is simple, back yard, shade tree repairs are not done in the best of conditions, using the proper skills, techniques or methods and epoxy can save your ass with it's extra strength and gap filling properties.

Be cautious with pressure treated plywood (PT). It comes from the store soaking wet and these goos need 12% moisture content or less to be effective as an adhesive. I've used PT and currently have a small stack in a steel storage shed. It's stickered up with a box fan running all day long. It's about 140 degrees in the hot Florida sun inside the shed, so it'll dry pretty quickly, but it's been there a month and the moisture content is still too high to use. Well saturated (with epoxy) marine grade plywood will be a faster choice.

You seem to have a good handle on things. Keep reading up on techniques, methods and materials in our archived, previous threads and post some pictures.

Good Luck . . .

[eyes]

Take the advice of the experienced people here.
You can take a look at http://www.rotdoctor.com/glass/GLrotrepair.html for some graphics.
I would replace all the stringers as i'm doing in a old boat i bought last year. Sealing and stiffing them with CPES is not recomended. Even if you remove the rotten part only moisture will be sealed again inside the wood and might rot in some time. Replace with new dry wood. Do the work one time.
The tramsom is already explained by others.

[Ehdrian]

Hi All,

here are the pictures! The names of the pictures explain what's going on.

After I took these pictures, we successfully removed 3 stringers.

Also, just for fun, a couple pictures of 'Misty' my Thunderbird Super Coupe.

[Ehdrian]

If you hover the mouse over the images it tells you the name of the image.

[Ehdrian]

Hi,

Just an update

We have taken out three stringers and I am looking to pre-purchace some supplies.

I have read some posts in this forum about - what to put under my stringers, so no hard spots are created.

I see that some people:

1. Just leave a gap - Water pool...
2. 3M 5200 - easy and expensive.
3. Foam

As far as foam... Any special type I should be aware of?

Thanks in advance!!

[Ehdrian]

Just an update:

I'm having the outdrives removed on Friday, and then the engines are being "craned" out on Saturday. This will give me access to grind out the rest of the boat on Sunday.

At this point (Monday) I will be ready to start fiberglassing.

If anyone knows what roving/cloth/mat layers I should do in which order (for the stringers) - for this kind of boat - please send me some tips. I'm not finding too much info on this. It seems professionals don't want to be held responsible for an amateur's job.

So I say: "No expert or amateur's advice will be used against them in the event of a boating accident, whether or not it was due to fiberglass and/or structural failure."

So, you are free to help. :-)

I have heard that the layers should become wider - so that each layer is bonded to the hull. PAR also mentioned that mat is used as a core material that is strengthened by stronger (roving?) fiberglass on the inside and outside of the layers. How many layers?

Thanks!

[tuantom]

I know I'm offering this a little late in the game for you; but last summer I had similar issues with questionable stringers. They were wet, but not really rotten except for one area where it was cut out for the fuel fill. I opened the top of them to let them breath and dry out for 5 or 6 weeks. Then I epoxied 3 layers of 1708 biaxial onto the existing single layer of roving/mat around the stringers. - It's pretty tough stuff.
None the less, 1708 biaxial cloth is a pretty good choice. I orderd mine from UScomposites.

[Ehdrian]

Thanks for the advice, but I had some serious water under all of the stringers. They all need to be removed.

This is a big job, and to ease other's minds who might be doing the same thing, you are not alone. Here are pictures of the engines being removed - to gain access to the transom and the motor mounts.

They used stupid square bolts for the engine mounts, in which I had to buy a special socket called a "gator".

EDIT: The photos are in reverse order. oops The first three pictures are of the truck crane moving the engines. The third picture is the crane operator.

EDIT2: The 6th and the 8th picture show the new stringers that will replace the old ones.

[Ehdrian]

Alright,

Another update, for those who are interested:

I was able to track down a professional fiberglasser that was willing to give me a tutorial. He recommends that I use Nytex (mat and biaxle stiched together) over the stringers. With his instruction, rounding the tops of the stringers and creating a curved/sloped stringer base might make it easier to wrap that stuff over the stringer.

Disclaimer: This is what I came up with, which is about HALF of the total fiberglass recommended by the professional.

Stringers:
- Tabbed in with 6oz cloth
- 3M 5200 under the stringer to reduce hard spots
- Encapsulate with 2 layers of Nytex = 2 layers of mat and 2 layers of biaxle

Transom (In order from gel coat to inside):
- Existing hull
- mat
- 3/4" Plywood
- Woven Roving
- 3/4" Plywood
- Nytex
- 6oz Cloth

Bulkheads:
- Encapsulate with 6oz cloth

I will probably change my mind once the fiberglassing starts, but this is the plan so far. If there is any feedback - it is welcome!

Cheers!

[tja]

Use mat between the two sheets of plywood in the transom. Not woven roving. The mat will bond the wood together much better. Do the baulk heads with biaxial rather them cloth. 6oz cloth is worthless. Two layers over the stringers sounds good accept the motor mount areas. There I would use four layers of the biaxial. It sounds as though the person that has been advising you knows what he is doing. Do it right once and then enjoy. Sincerely, Tom.

[e39dream]

any progress?

[Ehdrian]

Ya! Thanks for asking.

I have been at the dentist too much to put a full effort in, but here is where I'm at:

I have ground out all of the fiberglass, shaped all four new stringers and the new transom. I'm gonna make some chopped strand paste this weekend and fill in some gaps. This is to help me learn how to mix up resin... I'm also going to make a thin resin and soak the stringers and transom with 4 coats of the stuff before I put them in.

The plan is to put the transom in without the layer of nytex and 6oz cloth and to lay a bed of 5200 under the stringers and tab them in with 6oz cloth before I get the fiberglass expert to give me some lessons. This will make sure I don't mess up the structural parts. :-) By this time I will also have a bit of practical experiance.

I used a skill saw to cut the stringers using the old stringers as a template. The curved angle on the bow side of the stringers were also cut with the skill saw with the saw set on a 32 degree angle. (The angle of the hull)

The transom was also cut with a skill saw. I roughly mesured the horizontal top and middle of the transom and the vertical center. Then I roughly cut the basic shape. After placing the new transom board into place, I would see where I would need to 'shave off' more wood. I repeated the process until I had a snug fit. Because the starboard side of the transome required more grinding, the bottom of the hull was 1 inch deeper than the port side. (very thick hull) I shimmed up the new transom board on the starboard side with off cuts. Once this was complete, I noted how much more wood I needed on the starboard side and marked it on the board. I used this as a template for the second transom board and cut it to fit.

The properly cut board is going to go right up against the hull and the shimmed board is going on the inside. This is because the trim tabs screw into the transom very low and I want to make sure they have a firm hold.

I'll take some pictures and post them sometime in the next couple of days.

Cheers

[e39dream]

this 5200 I see mentioned on the forum- is this replacement foam? I need new foam for my project. can you tell me where to get it?

glad to hear your boat is coming back together!

[Ehdrian]

Hi,

I purchace the 3M 5200 at International Plastics. That's also where I get my fiberglass. Due to the size of the project they are giving me contractor pricing.

Places like Home Depot do not have this product... I would check with a local boat repair mechanic to see where he might get some. It is about $20 Canadian for a 10oz tube. This stuff is polyurithane based and is really sticky and tough. It will bind with wood and fiberglass, yet stays rubbery, which makes it a good base for stringers. Keeps the water out too.

I also used it to seal up my hatches, windows and anything I bolt onto my transom. It says on the tube that it can be used under the waterline as well - so I will use it to close up my outdrive seals.

Hope that helped!

[Ehdrian]

EDIT:

It isn't foam, or a replacement for it.... but a dam good sealer.

[e39dream]

I see- well then I will still have to look into it- thank you for taking the time to explain. I'm putting a stern drive in a boat that had an outboard, I could use a good sealant.

Did you encounter any of that bouyancy foam in your boat? Did you replace it?

[Ehdrian]

Ya, I encountered a bunch of that stuff. Although I have not replaced any yet, I understand it can be expensive. From what I heard it can be about $25/sq ft. If that is the case, it will cost me $750 to replace all the closed cell foam in my boat. I'm not looking forward to that!

[e39dream]

ouch! that sounds pricey! luckily my boat is only 18.5' :) Good luck to you Ehdrian- I'll check back on this thread as it develops.

[Ehdrian]

I have new pictures

The transom is in, however.... I'll be the first one to admit I did a hack job on it. The two boards are pressed together with mat in between (I think I did a good job on that - it was my first fiberglassing job.) :) The sad part is, the part of the hull where he transom was to be placed was not perfectly flat like the new transom boards. I had to 'squish' the hull toward the new transom using clamps and screws! I was so intent on getting the transom to bond with the wet resin, I rushed a little too much. I put about 10 new small holes in my gel coat.... I'll have to fix that now too. Also, I can tell that there are small areas of the transom that are not bound to the hull with fiberglass and resin (tap test). Dammit, but oh well. I would say that at least 90% of the transom board is bonded o he hull.

Good news. I cut the stringers to fit, and they fit very well.

The black stuff is 3M 5200 which I put into the stringer channel - used 2 tubes.

[Ehdrian]

Just finished getting the last stringer in place. I also just fiberglassed in the transom with nytex. That stuff soaks up a lot of resin! I think I'll tab it in with a few extra layers... just in case.... due to my problem I stated in an earlier thread.

The plan is to have the bow and stern stringer portions encased with 4xlayers of nytex and have the engine mounts finished and fiberglassed in tomorrow.... Then I'll take more pictures.

Hopfully I wount be far from glassing in the baulkheads.

Cheers

[Ehdrian]

Well, everything goes slower than expected right? I was able to fiberglass 3' in from the transom on he stringers with 4xlayers of nytex.

A word of advice for other would-be fiberglassers, like me: Make sure and wet down the wood you are fiberglassing before laying the first layer - this will make sure the wood does not suck up resin needed for the fiberglass and it will help to 'stick' the thick fiberglass sheets to the wood before more resin is applied. Using a metal roller, force the nytex into he pre-soaked wood, smoothing out the cloth and removing big bubbles.... then add resin.

I think I am allot better at avoiding bubbles in the fiberglass now.

[marshmat]

With practice comes skill..... and you're well on the way it looks like :)
It took me a couple of square metres of glassing over plywood to figure that out, too. (Wish bd.net had been around then, at least in the form it is now.) Wetting out the plywood, waiting until that just starts to gel, wetting it out again and then pressing the cloth into that- letting it soak up the resin from underneath, rather than forcing the goo in from the top- yielded excellent results in the end.

[Ehdrian]

I mixed up some regular baking flour into the resin when I ran out of chopped strand. That goop is brittle and not very strong at all.... so I rolled the rest up into a big 'potato' and waited to see how hot it got. I was hoping for smoke, but that didn't happen.

I have a question for someone:

Given that:
1. The resin is blue
2. The hardener is clear
3. As I mix the two - the resin changes from blue to green
4. I continue mixing until I see an abrupt change from green to honey brown
5. The resin cures and is very hard - no tack

After hardening... should the resin have a green tinge to it? Or does his mean it didn't cure properly?

Also, if I'm going to do two layers of fiberglass, should I wait for the first layer to completely cure before laying the second? So far I have been placing the layers on top of each other while the bottom layer is still gelling. I was able to do 4 layers of nytex in 30min.

Thanks!

[marshmat]

Also, if I'm going to do two layers of fiberglass, should I wait for the first layer to completely cure before laying the second? So far I have been placing the layers on top of each other while the bottom layer is still gelling. I was able to do 4 layers of nytex in 30min. What you're doing is right. A layer added on top of a layer that is still in the liquid or gel state will have a complete chemical bond to that layer- essentially, it becomes part of the same gigantic crosslinked polymer. If you wait until the bottom layer is hard, you're now dealing with a secondary bond and all the additional surface prep work needed for that. If you're careful to avoid bubbles, the only limit to how much you can do at once is (a) when you get tired, and (b) when it gets so thick that it can't dissipate the heat of curing (on the order of a couple of centimetres, depending on resin, catalyst and layup speed).
I'm not familiar with your particular resin and so can't speak to what colour it's supposed to be. A quick call to the manufacturer would probably be the safest bet.

[Ehdrian]

Thanks for the advice!

I live in a city where many people own boats, and have attempted to do what I am currently doing. Most times, the advice I'm getting is not always good advice, so I'm glad I can come here and receive tips from professionals like yourself. :-)

Please bare with me on this 'green resin' rabbit I'm currently chasing...

Lets pretend that the greenish resin in my fiberglass is indeed under-cured. Can I just put a heater to it? Or is this something more sinister?

So far, I have not been able to get a response from the manufacturer of the Polyester resin ... which is made by "Trimar". Is anyone familiar with this resin?

I have been working in he shade of a tree and mountain, and temperatures have dropped as low as 10 degrees C in the evening. I would compensate for this by adding more hardener - up to 2% of the volume of the resin. The resin would gel and get hard at the same rate as when I'm working in 20 degrees C.

Thanks in advance!

[Ehdrian]

Shoot! I found the answer here... not about the color... but about the 'what if".

http://www.boatdesign.net/forums/showthread.php?t=12963&highlight=cold+resin
and
http://boatdesign.net/forums/showthread.php?t=12713

Well, after I find out if it is supposed to be greenish or not.... I might try heating the stuff, if that doesn't work, I'll have to start fresh.

Still wondering what the color should be though.

[Ehdrian]

:idea: Thoughts and Musings :idea:

Apparently, the resin will always have a greenish tinge to it. No matter how much I heat and mix the stuff, it always comes out he same anyway. So I'm going to *assume* I'm doing this right. :-)

How to get the baulkheads level when the boat isn't sitting level and customize the deck height at the same time:

- I'm going to use the height of the gas tank as a reference.
- Use 1/2" ply for the base instead of 3/4" the manufacturer used (and glass it heavier)
- Lower the decking slightly to make room for a 6'1" person to stand up in (me)
- Keep all load bearing weight off of he gas tank
- Make an access hatch for the gas tank and assemble more baulkheads adjacent to the stringers to compensate for the missing load-bearing decking.
- Use weather striping for the seal? Is there a better non-water-trapping-idea?

That's the plan so far. I'll post more pictures when it looks better than it does right now. :p

If anyone knows how to make a hatch from scratch and seal it from water using plywood, please let me know! :-) When you google anything to do with hatches, I get a lot of information about how to order one. :-)

[frastorno]

I’m in the same situation but 50 posts ago, reading this thread is tempting me to start doing it by myself and learn along the way, 3 stingers, the transom and the deck.. Ehdrian: what do you suggest, would you do it again if you knew what you had to go through?
To start with a doubt that I’ll have to clarify either way, in the process of selecting the wood for the stingers at the sawmill, they proposed me several type of wood that are used here for boating or building marinas, are much stronger then tek (hard to drill !)and don’t have that oil thing that tek has (not good for the resin) and they don’t rot even if they are left in the mod for years. They proposed to me “Cocobolo”, “Balsamo” , “Guayacan” or Kira. I ordered the Balsamo (myroxilon balsamum) because was the only one they were able to cut the stingers in a single piece. I was wondering if I’ll have some prob in attaching fiber to it.. couldn’t find any of the woods suggested at the beginning of this thread.. does anybody has any experience with those woods? Anybody tried to glass them?

[Ehdrian]

Hi Fastorono,

I think your asking some personal questions on 'life-issues' here. :D

This is a lot of hard work. I'm single, I have flex hours at work and I have canceled many things I used to do in my spare time to work on this project (even charity work). If you have a wife, a boss that requires you on demand or responsibilities in your spare time, then your project will move ahead very slowly, I'm sure. :) I will put about $6,500 CA into this boat by the end of it all (although it will be worth over twice hat much when I'm done). Basically I have formed my life around this project for the last three months.

Stringers: I have no idea about those woods you mentioned. You might want to start a thread and ask some experts. I used Douglas Fir for my stringers and exterior grade plywood for the baulkheads. After careful research, I have never heard anything bad about Douglas Fir, unless it's wet, but hat's not the wood's fault. :) Wood should have 20% moisture or less before fiberglassing and heartwood is the best.

Chopping out the old stuff: If you are going to replace everything anyway, then don't be shy with the grinder. I spent too much time trying to save things in the boat I would have to remove anyway. Then in one weekend (30 hours) I just cut everything off at the base and was completely done - I wish I would have done that in the first place. People say fiberglassing goes quickly once you start, but that's not completely true! Surface preparation take a bit of time and will be the bulk of your work.

An expert told me that removing rotten transom takes 3-4 hours, however it took me about 10 hours to completely remove. Keep that in mind when recieving expert advice.... I remember someone in his thread telling me that everything will take 3x longer to complete than I think.... he was right!

I have enjoyed this project and have learned a whole lot I never new before. Yes, I would do it again - after a long break on the water, fishing, camping, cruising and hugging my current boat once it's finished. However, if I didn't think I would get it on the water this summer, then I'm not sure how much I would enjoy this project. My next project would be a hovercraft or a smaller boat - maybe a sailing dingy??.

EDIT: People have named my boat "Adrian's Ark" because I've worked so long and hard on the thing. lol, But I'm still naming it "Buscador Del Mar".

Hope that helps!

[thudpucker]

Thats a long enough project for a professional. As an ameture, you gotta set aside some time for the rest of your life. Its gonna take longer than you think. Get used to working at it during its appointed times. Extra time is ok but dont get burned out on it.
You need a buddy, and friends with 'stuff' for pulling engines n' such.
You need to build a warm dry shelter with plenty of lights and outlets for this job.
But keep this in mind. Its just parts n' pieces. You can do it!
Try not to buy anything until you are ready to use it.
I had one of those 24' Fiberforms with Mercruiser 140's. It went 31Mph by the GPS. Its another one of those things I wish I'd never sold.

[frastorno]

Now I’m scared!! :S . The good side of it is that I have a covered place were to keep it with all the tools I may need (about the part “don’t buy anything until you know what to do with it”..:) ) another good thing is that you have 25-27C degree, constant the whole year down here, plus have the gardener available to work on it full time, just not for too “deep” kind of things but it should increase my bandwidth and not mess up the rest of my life.. yes, I do have a wife, a recently born son and a boss to deal with.. But the work part is veery flexible. So, Thdepucker.. I think I’ll follow your suggestion, plus all the recommendations that come with it and start this project!
Ehdrian, I was wondering which part of the existing deck I could save yesterday, after reading your post I decided that this weekend I’ll get reed of everything. I read in some posting that you are not supposed to remove all the stringer at once because that could deform the hull shape, is that true also for a small 23 feet boat?
The only materials available over here are 1 type of resin (the blue one.. I’ll use your tips to balance the proportion) and only 2 type of fiber, a thick one that is a kind of ordered crossed tissue (vertical and horizontal .. row?), and a messy one and thinner (suppose this one is the so called MAT). Can’t find epoxies anywhere, only little syringes with a very little content and very expensive. Will I be able to do a good work with only these materials?
Do you have step by step close pictures of how you attached the stringers to the hull and transom and covered them with fiber? Should the stringer directly touch the hull or should it be folded in fiber first? I read many different versions on how to proceed with that. Plus, Which of the 2 material mentioned should I use?
Thank you both for your encouraging counseling and sorry for throwing at you so many questions. I’ll post my wood question on the material section of this forum. I’m getting ready for a huge and long adventure, but just during Saturdays.. and I’ll stick to it!!!

[thudpucker]

The USDA forestry has tables on the qualities of Various woods.
That's where I found out about White Oak being the best wood for resistanct to rot, mould and Mildew.

White Oak also holds a screw pretty good.

Go to your public library, tell tell the counter person what you want. It'l save you some time.
You may have the kind of wood you need right there in Panama.

Remember to Cover everything you take out of the boat. Wrap it up in plastic and weight it down so the wind wont blow it away.
Dont set anything right on the ground. Rust will begin soon.

Take a lot of photos before you start. You have room to store them on a CD. Be sure you get all the details of wire and cable location.
Coil up the wires and label each terminal. All that seems like overkill but you will be only too happy to have those photos later on.

[Ehdrian]

Good to hear your starting the project!

Thudpucker was right about the buddy... my friend Adam has put in almost half the hours I have into this boat for beer and free fishing. He has helped allot!

Tools... I made out fine with: Grinder with metal grinding disk, hammer chisel and screwdriver, Sander, Router, Skill Saw, Paint roller, Metal roller, Lots of mixing containers, Squeege, ratchet set and tape measure, ratchet set etc....

Removing the stringers.... A good idea is to grind the stringers out from the base and then lift them from the boat without wrecking them. This way you can use them as templates for the new stringers. Then take the grinder and smoothen the hull to the stringer channels (if there is any) so your fiberglassing is made easier. Also try and make sure you know where the stringer were - so you can put the new ones in later. :) The best way to brace the boat is to make a 'cradle' out of long 2x4s that 'hug' the bottom of the boat. I didn't do this though... I just put three extra stands along the bottom of the boat and one under the transom. These are in addition to the three already holding the boat up at the bow and chine. This braced the boat just fine for me, and now I'm finding that I'm building the boat more square than it was manufactured.

The transom... if you are going to rip it out from the inside and have access to the wood there..... Take a skill saw and cut from the bottom to the top of the transom about 6" apart and also from port to starboard, until you have a bunch of 6" squares cut. Then take a chisel and screwdriver and 'pop' the squares out until you have a thin film of old wood. At this point you can chisel out the thicker spots until all the old wood is about 1/8" thick or less, then grind it all off until you have bare fiberglass. Make sure and set the depth of the skill saw! And e careful not to grind through the hull anywhere! :D Remember that your trying to save the outer skin.

Fiberglass... I used the blue stuff, and I'm having issues with some of the layers, due to curing (not the resin's fault at all!). If your temperature is 30 degrees then you might want to only add 1% catalyst to your resin and fiberglass to a clean dry surface. Try cleaning the surface with acitone first and grind or sand a thin layer off of the surface. I had to learn through mistakes. ;) I used 1705 Nytex 45 degree and 1705 Nytex 90 degree for the stringers. I put 4xlayers at the tips of the stringers and 4xlayers in the engine area and 2xlayers in the middle of the stringers. This 'Nytex' is mat and biaxle stiched together and costs about $17/yard by 50". I'm using mat, biaxel and woven roving for the baulkheads and decking.

Sofar on this 24' boat I have used:
20yds 1705 Nytex
10yds 18oz woven roving
10yds 1.5 oz mat
17gal resin (2-3 gal lost due to not knowing how fast this stuff can set in the heat lol)

I hope this helps you get your bearing on the project.

Cheers!

[frastorno]

Thx for the info Thudpucker, I’m sure about the rot resistance, balsam is used for under water structure of marina’s decks and they last forever I just don’t know about how the resin and fiber stick to it, so I’ll try to test it tomorrow on a little piece of balsam, fiber glassing it and see how it behaves. I have all the metal parts in different plastic boxes, all the wood I removed was rotten so I just throw it away .. still more to remove. The boat was modified from inboard to outboard, so no engine on the stringers. I Have thousand of pictures already :)
Ehdrian, thx for your direction on stringers and transom, let me see if I can recap that step by step:
• First I’ll ensure the hull is cleared out grinded and well cleaned with acetone.
• I’ll then shape the stringers properly and have some layers of resin on it to seal.
• I’ll then paste them to the hull with epoxy (that would be using some of those dual tube syringes mentioned before), and let it cure.
• I then start fiber glassing 4 layers (mat, biaxial, mat, biaxial ... woven and biaxial are the same right?), starting from the top of the stringers and then onto the rest of the stringers and hull. I don’t need to fiberglass the whole stinger at once, the important is that the 4 layers on each portion are added at the same time. Each time I start a new section over a cured one, I’ll have to ensure that the previous layer is grinded and acetone cleaned.
• The wood of the stringer will touch the wood of the transom and them both fiber glassed together
Is this all right? I should be able to clear the deck tomorrow, remove the transom the following week-end and start the above steps the next one .. can’t wait! :)

[TerryKing]

The USDA forestry has tables on the qualities of Various woods.(snip)...Go to your public library, tell tell the counter person what you want. It'l save you some time.

Or, look here at the BoatDesign Wiki:
http://www.boatdesign.net/wiki/MaterialsForBoatbuilding#The_US_Forest_Service_.22Wood_Handbook.22

The Wood Handbook is online....

[Ehdrian]

I didnt use epoxy anywere, although that stuff is a lot better than polyester, from what I hear.

I put 3M 5200 under the stringers - its similar to other sealants exept for its amazing ability to adhear to wood and resin... it also stays rubbery. This reduces hard spots in the hull - so when you hit a wave the hard shock is somewhat absorbed by the rubbery 5200 instead of the fiberglass, which can cause the hull to micro-fracture which lets in humidity under the stringers.

You could also put foam under them, or just leave a gap.... but I'm not sure how that works.

Cheers

[frastorno]

Was reading from the wiki article that TerryKing posted, btw, thx! Excelent info there!.. but no mention of the "balsamo" wood! :(
"3M 5200: A rubbery, polyurethane sealant in various colors with adhesive properties sometimes used as a glue. Fails as a glue under water saturation without high clamping pressure, and without the proper strength testing I couldn’t do here, it’s not recommended as a stand-alone marine glue. Repairable with epoxy."
I also read other postings saing that the stringer should be solidly attached to the hull as a sole body, is it your a "test" or someone reccomended to proceed that way? BTW, I finally found a bigger 2 tubes epoxy that cure in 2 hrs (the little syrings I mentioned were curing in 5 mins!.. hard to place a stringer in that timeframe!!).. it's from Loctite, the name is Epoxy-Mill.. anybody ear that?

[Ehdrian]

This is an example of where I got some info on 5200:
http://www.vintageraceboatshop.com/EdgeBondingProject-1.htm

This is an example of where I got info on hard spots... if you do not shape your stringer perfectly to the shape of your hull, you may need a 'padding' under the stringer, at least. So I tried to do both, myself:
http://www.yachtsurvey.com/HullFailP2.htm

Cheers

[marshmat]

5200 has its uses, yes, and it's good stuff when used as intended. But at eighteen bucks per caulking-gun cartridge, there's gotta be a cheaper alternative.... or are the local stores just in cahoots with their rip-offs?
Loctite stuff is generally very good and very expensive. I haven't used that particular one though.

[frastorno]

Good news! The fiberglass perfectly adhere to the “balsamo” wood and I found a shop that sells the epoxy here in Panama (thx to TerriKing!), I read the article about the “soft bounding” of the stringers and I’m now a bit confused, it seems that there are different opinions about it: strong and rigid bounding with epoxy or soft with some elastic glue .. Marshmat, what’s your opinion about that.. I also posted this question in another thread: (http://www.boatdesign.net/forums/showthread.php?t=6290)

[Ehdrian]

Hmmm, I'm far from being expert and have no practical experience with this. If someone says you can hard bond to hull, then go at'er. :) I'm sure you would need to make sure you have the stringer perfectly grafted to the hull first. IMO

[marshmat]

Strictly from a first-principles engineering standpoint (I've never done the repair you are doing), you should match the product E*I (elastic modulus times area moment of inertia) among each discrete component of the combined structure. In layman's terms, each individual element should require roughly the same force to bend roughly the same amount- ie, it's all the same stiffness. Having one soft element combined with one hard element causes most if not all of the stresses to become concentrated at the weakest point of the harder/stiffer element, which will thus fail prematurely.
In a wood/glass stringer, you achieve this effect by giving the low-modulus part (the wood) a very large area moment of inertia (its large cross-section), while the high-modulus part (the fibreglass composite) has a smaller moment of inertia. In the ideal case, forces are thus spread throughout the structure. Using an excessively soft component would concentrate the stresses into the thin tab of fibreglass at the joint, rather than spreading them out along the entire stringer bed.

[TerryKing]

The original construction on any boats I've seen is intended to make the stringer and hull basically one fairly rigid piece.

There IS a problem with getting a good fit, and not having gaps between the Stringer and hull. I have used fiber filler with West Epoxy for a strong joint. Others have said that they put a strip of glass matt or roving (thickly woven figreglass cloth) between the stringer and hull to hold epoxy and conform. That sounds OK, especially if the fit has gaps of up to 1/16 or so.

Maybe the combination of a matt and thickened Epoxy would be good in a case where the fit is none too good.

In terms not as exact as Marshmat's, it should end up as one solid unit...

[Ehdrian]

And there you have it! :D

[frastorno]

Ehdrian, I hope I’m not jeopardizing your faith in your boat basement :D .. I’m sorry I had to dig in :( !
This is my plan so far then: I already have the balsam stringers, the Epoxy , cloth and mat. I’ll clean the bottom of the hull as much as I can, acetone first, grinder after. I’ll shape the stringers to adhere as much as possible to the hull and paint it with at least 2 coats of epoxy. I’ll order some fiber filler to add to the epoxy (does any filler works or needs to be fiber? They only have graphite filler from west marine at the moment, anything else should be ordered from US and that would take at least 2 weeks) and will paste the stringer with that. I’ll then fiberglass everything with epoxy, (which fiber should I use, cloth only or mat first?).. Sounds good?

[Ehdrian]

Not at all! :)

I had a fiberglass professional scope out my work so far, and he said that I could lay my work bare to a marine survey and not have any issues or second thoughts.

But it was nice to hear from him that polyester is good enough for a boat and that epoxy isn't a god sent to us from 'boat heaven'. I also saved $3,000 on the project by just not using it. So, so far I have no regrets. :D

[frastorno]

:eek: 3K$? now I'm getting worried.. how many gallons will I need for 3 stringers and the transom? Also an aprox would be good just to recalc my budget :( .

I have half boat cleared now (decided to do 1 side at a time to avoid deformation of the hull), I only need to sand the hull and clear with acetone.

I cut a pice of the internal fiber of the transom and the wood behind is totally rotten as supposed. so I'll have to replace that also. How should I proceed, do I need first place the transom or the stringers? How did you do that Ehdrian?

Can I use a good strong and water resistant wood instead of plywood for the transom?

[Ehdrian]

Well, I'm on my 21st gallon of polyester restoring a 24ft with 4 stringers. I figure after all the decking is in and the boat is empty but 'finished', I'll have used 25+ gallons of polyester. 5 Gallons of polyester cost me $100 how much is ONE gallon of epoxy and hardner?

I don't want to scare you off, but that's why I chose to use polyester. I have a polyester hull anyway.... Epoxy is a far superior product no matter which way you look at it.

Here is one thing to keep in mind. If you start using epoxy, you have to keep using epoxy, because polyester does not stick to epoxy. So you can't switch back half way through if you run out of money.

Cheers!

[Ehdrian]

You can use all sorts of great materials for your transom. It would be in your best interst to use at least marine grade ply.

I took my stringers out first because they are butted up against the transom. I found it is easier just bracing the bottom of the boat and ripping everything out. This way I could put the transom in first and then butt the stringer right up to the transom.

[tuantom]

Frastorno,
You can re-attach your jaw now - there are multiple sources for epoxy. US Composites will sell you 25 gallons of epoxy for about $1,000. There are also other companies in that same competitive price.
To figure how much you'll need, the weight of the cloth is per yard. If you need, for example, 5 square yards of 20 oz cloth, you'll need, at minimum, 100 oz of epoxy and hardner. You're probably not going to be so efficient and will use a bit more; but a gallon would be plenty.

[frastorno]

What a fun is to sand fibrglass! I think the trick is to find the balance between the right number of layers of cloths that protect you from the hitchy and that don't make you melt under the sun!

I have to do the same job as you did, so I guess I'll need 25 .. or more given my fibregalling non-expertise. Here in Panama it costs aroud 100$ per gallon (WestM).. and it's the only epoxy availiable, it took me a wile to find it.. the main reason I was thinking about using epoxy is because I read that it's much more easy to apply and a "newbie" wuold do much less damage while learning fiberglassing.. is that a mith? I can still trade my gallon of epoxy for some resin's ones..
About the wood to use for the transom.. my question was because plywood is much more expensive of real wood down here ( even very good wood, balsamo, cocobolo etc).. so do you think I can go ahead with balsamo again? even I'll have to use atleast 2 different tables?

The hull seems to be so fragile now on the side a cleared up that I'm scared about pulling the transom also, without having the striger back on place. I'll follow your procedure payng a lot of attention at were I put my feet!

[frastorno]

I understand that Polyester can't be used on Epoxy but Epoxy can be used on cured polyester.. so, can't I do stringers and transom with epoxy (to be sure of the structural part) and then fiberglass with poliester the table that support the deck, let them cure and then attach them with epoxy to the stringers and transom.. and use poliester from there for the rest of the deck?

[Ehdrian]

I have no clue :D To any of your questions... :confused: and I guarentee that I wasted more resin than you ever will lol

[frastorno]

I guess we are all learning here ;) .. let's see if some one else has some input.. in the meantime I'm seriously reconsidering the epoxy thing, the gallon of polyester costs 16$ here against the 100$ of epoxy:!:

[TerryKing]

I guess we are all learning here ;) .. let's see if some one else has some input.. in the meantime I'm seriously reconsidering the epoxy thing, the gallon of polyester costs 16$ here against the 100$ of epoxy:!:

I've used both over 35 years. I 'fixed' boats with Polyester, but they didn't STAY fixed..

Unless your boat is worth less than $100 - $16 = $84 I'd go with the epoxy.

The other good thing about Epoxy is that it has a long shelf life. I just used some 5 year old West 105 and it handled perfectly. So you can use it for lots of things, like your rusty pickup truck... And your boat repairs next year.

I always cringe at the price, but then I'm so glad to have it there...

[frastorno]

Thx for your input TerriK, well.. that would be 84*25=2100$ and something if you consider the 3 stringers the transom and the deck, and that's probably what my boat is worth.
Do you have any suggestions about the other questions?:
-Is epoxy much easier to use? why?
-Is there any reason why using pplywood and not a good non rotting and strong wood for the transom (balbamo, cocobolo, etc..)?
-can't I attach the stringers and transom to the hull with epoxy (to be sure of the structural part) and then fiberglass with poliester the table that support the deck, let them cure and then attach them with epoxy to the stringers and transom.. and use poliester from there for the rest of the deck?

[TerryKing]

Thx for your input TerriK, well.. that would be 84*25=2100$ and something if you consider the 3 stringers the transom and the deck, and that's probably what my boat is worth.
Do you have any suggestions about the other questions?:
-Is epoxy much easier to use? why?
-Is there any reason why using pplywood and not a good non rotting and strong wood for the transom (balbamo, cocobolo, etc..)?
-can't I attach the stringers and transom to the hull with epoxy (to be sure of the structural part) and then fiberglass with poliester the table that support the deck, let them cure and then attach them with epoxy to the stringers and transom.. and use polyester from there for the rest of the deck?

Wow, that seems like a LOT of resin. Why so much?? I would have thought a couple gallons for the stringers and the new glass covering them.

My opinion on other stuff: (Others please comment on your experience!)

- Transom wood: I used well scrubbed and dried pressure-treated plywood, coated with epoxy, especially end grains, and then bedded with thickened epoxy as others have mentioned. About 7 years and totally solid now.

- (You mean 'floor' when you say 'deck' I assume. What is the 'table that supports the deck? Does the deck sit on top of the top of the stringers?). Well. You certainly could make the deck separately, using only polyester and glass over (again, I'd use pressure-treated) plywood. Then attach with screws so you can get inside once a year to clean / inspect. Screws into the stringers should be screwed in, then screws and the deck removed, and then screw holes drilled out and epoxied, then screws pilot-drilled and reinstalled. This way screws go only into epoxy, and no water can get into the stringers. Pain but worth it...

Others: How much resin did it take to do 3 stringers on a boat like this??

[Ehdrian]

I'm sure he got the 25 gallon idea from me, but that is how much resin i am going to use to finish the whole boat, not just the stringers. As you will see in the pictures below, I am a little further ahead and have not used 25 gallons yet.

Pictures:

Many little baulkheads cut and soaked in resin 2xtimes, then mat applied to both sides.

The bow has been glued/set in place but not fiberglassed yet.

Engine mounts cut and waiting.

8xLayers of fiberglass on a stringer,the back looks uneven because I have walked in that area many times and attracted dirt.

[frastorno]

Yep, my estimate was based on Ehdrian's comments, I have to do almost the same stuff (basically everithing!).. but even if it was only a 15 gallons deal, there is a difference off thousands $.
I'm in US this week (Austin), I finally found the fiberglassing alluminium rollers that everybody is talking about! I guess I'm another little step ahead :)
What about usability of Epoxy, is it really much easier then regular resin?

[frastorno]

Ehdrian, how many gallons you used only for the transom and stringers?

[Ehdrian]

Well.... 17.5oz /sq ft Nytex at 25yds by 50" wide which covered 4x stringers ~16ft each with double layers at the tips and engine area and also 2x layers on the transom with extra tabbing. This... and I think I have it right... is a total of 13gal of resin plus about 2 more needed for waste and fill, which would be 15gal.

This would be close to what I used, but your boat is smaller so you might need just 10? I might have also wasted a lot of resin in the process, but I have no real way of telling because I had no experience prior to this. All I know is that I'm now on my 22 gallon of resin right now after coating and fiberglassing the baulkheads heavily with thinned resin for waterproofing.

I don't worry too much about adding extra weight to the boat, so I use fill wherever needed, which has used close to 3gal of resin (including waste). I used chopped strand fill for rounding off areas to allow the fiberglass to bend easier over the corner where the stringer met the hull... etc... 5gal of polyester is about 44 pounds, so 5 extra gallons of unneeded resin is not a concern to me as long as water doesn't get into the wood.

Personally I wouldn't go home without 10gal, and if you bought 15 you would have close to the amount you will need to finish the project.

In short, I'm resin happy without a care :D

[frastorno]

I now have the transom almost grinded :mad: , I should be able to start rebuilding it next week.. I'd also like not to worry about how much resin I use and make sure I don't left any hole behind. Still thinking what to use but if 10 gal is a decent aprox I'm more toward regular resin. I still have 3 questions you can help me out with:
- Do you have first to grind and then use acetone to clear or the opposite?
- Once you built transom and stringers did you do everithing at once or not? If not how did you guaranteed the structural continuity between transom and stringers?
- I understand I have to apply some layer of resin to the stringers and transom woods before using them. DO I have to let them cure first or just apply resin and while fresh install the wood and fiberglass?

[jimslade]

Go with polyester resin. Epoxy is a waste of money on a boat that was never built with epoxy. I would use a iso poly instead of an ortho. The iso is better for the small price increase. Do one side stringer than the other. Never never gut a boat unless its in a boat cradle. You will rack the boat and make it worthless. Use an unwaxed resin or you will have to grind and dewax every lamination layer. Just a fact to think about, 99.999 boats today and yesterday are built out of polyester resin. And yes vinylester resin is still poly , and it is usually only used for an outside layer to stop osmosis. You can feel very confident that polyester resin if applied properly will do a good job. I would spend my extra money on using a better fiberglass. The savings will allow you to redo the interior.
Have fun, and keep scratching!

[frastorno]

How do I know if it's waxed or not (or poly instead of ortho)? The bottle just say resin and the vendor has no clue.. it is bule and the hardener is clear

[Ehdrian]

The store selling it should know if its waxed or not. Some of the containers even have a box with "waxed/unwaxed" so you can see for yourself.

Cheers

[Ehdrian]

Maybe I should have read your post a bit better lol

You should call the manufacturer if uncertain. Thats what I did.

[frastorno]

I think I'll go with poly, about the fill/glue tu use under the stringers: is the chopped strad fill just matt fiber cutted into little pieces? If yes, should I add talco too? Talco was the only fill I was able to find here and order stuff from US take time and money.

Edhrian, about the "pre-tratement" of the wood: did you coated the wood, let it cure and then fiberglassed into the boat or you did it all at once with the resin on the woods still wet? Did you ude acetone to make the resin thinner?

Anybody knows anything about peel-ply, should I use it if I'm not able to do all the stringers and transom at the same time? how different is it from a normal plastic wrap?

Lot of questions, like usual!:confused: ... thanks to the people on this thread for their patient and support!!!

[jimslade]

Never thin resin, it affects the hardness. Unwaxed resin will stay slightly tacky after it sets up. Regular bodyfill is talc and resin. Don't let the stringers touch the bottom of the boat, it will set up a local stress point that can crack the bottom of the boat. Set the stringers on a thin piece of foam. Don't use peel ply that's for vacuum bagging fiberglass.`

[frastorno]

Had a different input, about 2 pages ago on this same thread suggesting that the bond stringer-hull has to be rigid (filled resin), are you sure about the foam sol? Should I use the same sol that Ehdrian suggested (3M5200)?
--
I know I'm changing topic here and I'm sorry,but I just don't want to open a new thread just for it. Is sombody able to tell me who is the producer or which model is my boat? no references on it, if you need any detail just let me know..

[jimslade]

If anyone suggest that you set the stringers to the hull with a hard filler, Please ignore their advice. They don't known the first thing on navel structural engineering. A soft joint is the best. Same with the transom, it should never touch the bottom or outside edges. 5200 is a waste of money to set them on. A small strip of foam will work fine. I use Nidacore and because there is no hard edge, I set them directly on the bottom. I'm making a wild guess but that looks like a 1977 fiberform. A friend of mine had one like that. They are a great boat in the rough stuff. Check out Dawsons marine, they have the original papers for most boats. Send them the pictures, they have helped me out with two older boats I have.

[Ehdrian]

I used acitone to thin the resin and then apply 2x coats to the wood - especially the edges... but I didn't stop there - jimslade is right, it reduces the hardness a lot! I also find that the resin sometimes doesn't cure very fast when thinned (1-2days) So I made sure that each peace of wood had one more coat of regular unthinned resin and at least one layer of mat overtop of the 2xcoats of thinned resin and 1x coat of regular resin. I think this will waterproof the wood enough.... I am going to use 3M5200 to bind the deck to the baulkheads, so I don't use screws, and where I do use screws, I am going to fill the hole with resin and contersink - so the screws are imbeded into the resin, not the wood. I got that advice from another thread on this site.

If you don't let the resin completly cure before adding another layer - you come out on top. In this thread I was told that adding layers as they gel will cause each layer to bind to each other and create one big polymer, which is good. Waiting for each layer to dry will require you to sand the surface to create a mechanical lock.

Dam! I've learned a lot through this process..... This is like chemistry class and fun mixed together lol.

You have a fine looking boat there! Makes me want to finish mine faster and get out on the water! :-)

Cheers!

[frastorno]

OK, thx Jimslade, I'll go to the local supplier to see which "soft" glue/foam product they have availiable and post it here to see if you think it works. Checked the site you mentioned (www.boatingwithdawsons.com) but they ask you to pay for any doc, and no e-mail on the site.. I'll keep searching for fiberform 1977, couldn't find any similar boat so far.
Ehdrian, do you have some new pics of your boat.. I need to see that it is possible!! I'll wait for jimslade comments on your procedure to saturate wood.. makes sense to me. Yes put it in the water and go sur for a while and cross the canal so we can go out fishing some Merlin together!By the time you get here i may have finished mine too!

[frastorno]

Scratching the back of the transom I was able to find the serial of the hull, loking at the first 3 digits (XVA) it should be from "Invader corp" looking at the last 4 (M80J), it was built in 1980.. right? Now: how do I do to have the plans or specs of it? no traces of it in internet

[jimslade]

I need the whole serial number to decode. Thin resin with 10 percent styrene. Or use well dried out pressure treated wood. Thats what I use when I have to use wood.

[frastorno]

XVA28301M80J this is the complete serial, I'll look for syrene.. thx for the info

[tja]

Hello, The serial number will not end with a letter. The letter indicates the month it was built. I believe the j would indicate the month of September. If I remember I'll check today at work. Sincerely, Tom.

[frastorno]

J should be May (of 1980) and XVA should be GULF CRAFT YACHTS INC (Invader).. but then how can I find model and specs? No traces of this company in the internet ... Looking at some picture of boats on sale, it is similar (but not the same) to the 21 Invader cuddy cabin, but it was of 1991.. is there any database when you can find your specific serial code?

[jimslade]

I know where there is a 21 invader cuddy for sale. I know it is new and has never been sold. I don't know why. Its been in a boat dealer storage lot for years. Next time I'm by (usually once a month) I'll check it out. Dawson's Marine is the only people that I know that have any info on boats. They helped me find info on my wifes Oliver boat. And thats rare one. If you can phone them, its the best way. I don't know what the phone rates are but if they are high, I will call for you. They are in my area.

[tja]

I was wrong about J being the month of September. J is for October. You start with A for January and progress from there. Usually the month is after the production run number which in your case is 301 . I did see a boat today that i was working on had a letter after the year. Coast Guard rules require the month of production be in front of the year from what I have read. Sincerely, Tom.

[frastorno]

Thx Tom. Jim, if it's not too much to ask, I'd really appreciate that.
That '91 model (invader cuddy that I pasted below) is not exactly the same.. could that be because is 11 years younger?

[jimslade]

Thats the same model as for sale up here.

[frastorno]

I found the styrene to make the resin thinner for the wood, but they told me to use 1/4 of ounce each 1/4 of gallon of resin.. that's less then 1/100 like the catalyst.. are there different type of styrene? .. or he simply didn't know what he was talking about?

[jimslade]

You can thin down 5 percent, no more. This should allow for a better penetration into the wood.

[frastorno]

Am I supposet to add the catalyzer first and then the styrene or the opposite? Or that makes no difference and the only important thing is that I mix everithing very well?

[jimslade]

styrene first, then 1 percent mek. this will allow a slower cure for penetration.

[Ehdrian]

Hello

here are some more pictures on the project. This shows the structural grid and the deck/floor going in.

There is also a picture of the engine mounts being assembled.

[jachristner]

Looks like it's coming along nicely. I've been looking for answers to a lot of the same questions you've had so I'm happy to have found them here. I have a 16' 1969 Starcraft Polaris with rotted stringers, sole and transom I'm hoping to repair over the winter. Right now I'm still in the process of finding a work area that'll keep the snow off of me. :)

I've had some advice about polyester resin and if I remember right, waxed was suggested to me. You mentioned the unwaxed still being tacky after fully curing. Does this mean the final layer needs to be waxed? I understand that a full cure between layers will require surface prep between them. If the layers are done with waxed and laid wet before the previous has cured, will it also cure as a single layer?

[Ehdrian]

As far as I know you don't need to use waxed resin if you at least allow a good 3 days of curing time in hot weather for the final surface.

The wax rises to surface of the repair and creates a barrier that helps the resin cure completely. If you use waxed resin for your whole project, you will create serious problems if you do not scrub the wax off between coats. But doing things this way will also require grinding and/or sanding to create a mechanical bond. Mechanical bonds are weaker than chemical bonds.

I didn't use a single oz of waxed resin throughout the whole project.

Cheers!

[Ehdrian]

PS. I'm still working on he project, even though I haven't posted pics lately. I'm currently finishing the engine area, fixing some mechanical issues and glueing vinyl and foam to the hull.

I have to transport her to another location, but after that it shouldn't be much longer before the launch.

[oops!]

oops! here from kelowna
congrats on the van island raiders winning the bcfc championships!
on to the canadian bowl!
hows the repair coming. im about to do my 68 sea ray. same stuff as your doing. whats your take in the repair? worth it?
or before i start my re-fit should i just get a gun and shoot myself?

[Ehdrian]

Hi Everyone,

I have received a few emails about the project over the last year and kept forgetting to post here!

Life has been busy! I started a new software company which is going well, but it took me clear away from working on the boat project, however, The boat is nearly done.

The galley and the head are almost in, the vbirth is complete, the hull liner and vinyl is finished, the floor and floor trim is almost done and the outdrives have new impellers and are all oiled-up.

I'll try to remember to post some pictures :-)

I used
1/2" foam and vinyl for the hull liner (Foam glued down and vinyl glued at top and bottom only)
Fiber-floor for the floor
Interlux primer for the engine area and bilge
Spray foam for around the sliding glass door
All sealent is either 3m5200 or sicaflex

I plan on
Using aluminum angles to build bench style seating/compartments in the cabin
Building a removable dog house with livewells

Need to finish
Some fiberglassing in the engine area
Tilt motor is shot
Wiring


I think the launch will be this summer.

Her name will be "4Bits".
Because:
- That's how much everyone thought she was worth before all the work
- She's for bits of fun, for bits of fish and for bits of exploring
- 4 bits is the type of computer I first used when I was young

Never give up! ;-)

Cheers!
Adrian

PS I would never have gotten this far without all of your help and encouragement! The fiberglassing and grinding is nearly done. :-)