transom repair opinions

[swade]

big progress this morning!

practically all wood is gone, just some thin bits and cleanup here and there left. Most of the ply is off the flat the rest is a very thin veneer in areas I didn't sand off yet, should come off when i go to tooth with the 24 grit.

Tools...hate to say it, i did 95% of this with hand chisels (cheap ones as they'll get tore up pretty good from the staples. 5% chainsaw to get the meat from the flanges, and 5% probably some randon tools I was trying. I think that planer probably would have been good for the flats but nothing did as well as patience, chisels and hammer. After a bit you get a rhythm of how to hold it and take off large chunks, pry, and twist to remove other chunks.

I think i'll get an air disk sander as those are easy to get 24grit disk for, i'll use that for the rest, flip the disc around to get the outside flanges.

Not sure what's next i think i need to get the pooled resin out from the bottom (as you/par mentions), so tonight i'll reread the threads and figure out my materials list.

[swade]

Classic.

I guess my understanding of manufactures stringer descriptions is newbie too. Turns out the stringers are glassed over wood. Like everything on this boat things are just partially bad. 2 bottom stringers look very solid which is odd as they sit the lowest, this indicates to me it came from the transom side of things. the 2 knee braces well..they need to be replaced they have a bit of rot on the ends, about 80-85% solid meat there. Unfortunately I can't tackle these atm...neighbors are getting uppity and it will be a month before i get a nice private side carport and driveway in so i can work on this type stuff and be code compliant.

So ...considering there still seems lots of strength back there and I need to get it out, onward with the transom. I'll look at the knees in a month or 2, i think i can access them from the bilge or putting in some access ports. In hindsight should have drilled to double check them and gone through the top.

That's ok! I got this boat cheap, i'm learnin...don't mind hacking or even dumping this one off. i'll be much smarter the next time. But at this point it's just partial things you'd expect of a budget boat this age (aside from the transom) so i'll finish the transom, get my carport built, then tackle this other thing in a month.

[swade]

I have a couple of questions (been reading the previous threads)...

next i'm going to break up the pooled resin and tooth (picked up a disc grinder and psa 24 grit disc this evening)

Then i re-enforce the inner liner, my questions there are do I:

a) cloth the entire inner liner up to to the top? How many layers?
b) do I wrap it around the flange corners as well to renforce the sides?There's a bit of uneven areas on the sides (exposed mat,etc) I assume i should filet those a bit better before tabing in the cloth there.
c) What type cloth do i use for the inner liner and the beveled outer skin? I usually buy materials from fiberlay as they're close. I'm not familiar yet with the various materials. They have biax 1708, cloth 4,7.5 and 10oz.
d) Will a gallon epoxy be enough?

I can re-enforce the inner liner, then do the 1st sheet of transom core the next day right? Or does it all have to be done in one go?

Sorry if these are dumb, brains a bit much from reading so much.

Rest of the stuff i have from other projects..cabosil,microbubbles,etc. I have matched gelcoat as well from other projects, I'd like to use that but i understand there's some particulars with using epoxy for the repair i have to read up on.

[swade]

Hi ALL! All clean and toothed =) but I *really* need some experienced input on something the bit of rot on the end of the knee's is bugging me.

is the putty on the back of the spashwell supposed to be bonded (as was seemingly here with putty?) to the transom?

As that's going to affect my knee brace replacement plans later on...

Notice in the pic (glass doesn't go to the top, that's the back of the splashwell which i assume is a type of putty. i imagine how this worked, they did the transom, put the cap on and there was putty or something on the back of the well/transom thus bonding it a bit to the transom laminate. What i sanded off in that section was nothing more than resin but wood did go to the top of course.

Problem..if i do the transom now, and go back to cut the well to fix the knee's later i'll damage the inner liner on the transom. IF however it's not supposed to be puttied/bonded to the inner liner I can put some wax paper there, re-enforce the inner skin, do the transom. Come back later, cut the well out, and fix the knees, put it back and even putty the back of the new transom before putting the well back on.

If it's supposed to be bonded, well..i'll have to put it off and cut the well out before doing the transom.

I don't think i can reasonably fix the bit of rot at the end of the knees without cutting the well.

[PAR]

It doesn't have to be bonded, though if it is, it does stiffen things up quite a bit. So, if running big HP, you might consider bonding, if not, wait until you've fixed everything (eventually) then bond the crap out it and call it done.

[swade]

Thanks par! I appreciate the information, i think i've read every one of your replies a few times on this topic the last few days i'm trying my best not to rehash old stuff and RTFM.

Looks like for the outer skin I use 12oz biax fabric or tape ..4 layers in the grind back areas of the outer. Will this be ok to re-enforce the inner too? maybe a layer or 2 there?

This will be my first go round with epoxy (you've discussed that with me on other theads), I'm not quite sure how much to get, 2 gallons? I have to re-enforce the inner, coat the 2" core, plus leave some for the trowling, patching things back up.

Plus i'll have to practice with the epoxy ...have only used poly.

liki, that belt sander worked great, only i've read the cheap (aka harbor freight here in the states) one's are pretty chintzy on the belt assembly portion. I had picked up a steal on a dynabrade awhile back and it worked great. That said i had a 2" gap to work in, just enough room to hold the body against the inner liner while the belt portion worked the gap..if core is 1.5 not sure how easy would be to get in there. the dynabrade is pretty big through. disc sander fliped backwards worked best for the flanges. I used cheap chisels, the belt for pooled resin and flange sides, disc sander for the back flanges and toothing overall 24 grit.

[PAR]

A multi-tool work well in those confined spaces.

I'd be surprised if you needed more than a gallon of goo.

At least 4 layers of biax on both the inside and outside (yea, I know it sucks), to restore the stiffness of the core/flange/skin and tabbing areas. Lots of thickened goo. You can under do the amount of materials (fabric and goo) and have problems, but it's hard to over do the materials and screw anything up. Keep this in mind when you think "maybe it's good enough".

[swade]

Ahh i see yeah, re-enforce the inner makes up for the outside and stiffens the whole thing. Gotcha thanks! 12oz biax (no mat for epoxy), 4+ layers. Gotta go get ply and supplies this week.

fla rain was a killer end of last week, no progess...might make some progess this week, i have to bring it from a storage yard and back now as i'm working on a side parking area so i'm all legit trailer parking code wise.

[PAR]

4 layers of fabric is the minimum. You can't go wrong if there's more, but you can if there's not enough.

You're getting the same rain I am and yesterday was the first sunny day in a while. We've had several days of rain, so I haven't gotten much done either. Since you're over there in Apollo you should look up Fiber Glass Coatings inc. St. Pete. You'll get better epoxy pricing then West or System Three and they sell fabrics too. Give them a call or check their site fgci.com

[swade]

yeah can't wait for the skeeters after this rain, they are real healthy around here.

i'll certainly go at least minimum erring on the side of caution.

I think i've read everything thread on this and don't see anything in the west pdf about this either...maybe it's more general tabbing technique. Found plenty of info on the outer skin, But for the inner do i tab the new inner renforcement to the side of the 'slot'? or should i tab around the slot corners onto the backside of the flange?

TA Mahoneys close by me sells FGC that i've used but thanks i just checked the website and they are definently a bit cheaper than the other supply on the epoxy too, i've been thinking about making a trek over there.

[swade]

Monsoon is over! Will be back at this in around a week or so. Been reading up on tabbing and bulkheads and the such, All of this makes me realize it's time consuming to figure out another how to project and I really should limit myself when it comes to projects and let a pro do some stuff (if only the boat value was worth that). However I think this is something I'll potentially repeat and I gain some howto with epoxy and biax. Until know I've just been doing mostly visual/non structural stuff on the boat with poly/matt.

Hardest part is with reading all the threads on this no one ever goes into much detail on this part.

So my plans are to rescuff everything due to the rain then:

* lay 4+ layers 12oz biax on the inside face

* slightly refilet the inside lip corners, not sure if this is needed but it's likely i don't have a perfect rolled seam there from the grinding,etc and my understanding is this will avoid hardspots and
voids.

* "tab" the inside face in with various width layers of biax to eliminate hard joints ie all tab layers ending at same place. Now when I think of tabbing i think of going back a ways, but here you have a 2 -2 1/2" gap to tab into. My guess is I should tab that inside renforcement , but also alternate tabbing layers also onto the outside shell (on the inside). Either way i can't see how it would hurt.

I'll do all of that in one go. Is it ok to separate the process of renforcing the inner liner with doing the new core? Or should I do 100% everything in one shot?

[PAR]

In a perfect world, you should do it all at once, but the inside operations and exterior will be relying on mechanical bonds in various places so, do one, then the other, as time permits.

You have it about right; stagger the tabbing seams so they don't all land on the same spot. Over lap the hull shell (both inside and out) by as much as you can, with several inches of internal hull shell contact being ideal. Fillet the corners so the fabric lays down nice, but also to add additional strength to the core/hull shell interface.

[Neil.Liu]

have you ever try SBC panel for your transom? I have some customer who are using this material for transom and easily fix screw. Another benefit is water absorption, 0.1% after 28days. Single layer is around 10mm and customer are using two or three layers of SBC. In between SBC they are using csm around 225g/m2 to increase the mechanical property. I get some cooperation between Balsa and SBC. Hope this can help little bit.

[swade]

Well maybe in the next 2 weeks i'll get to putting things back, been tied up with life house,kids,work. Did have a quick question though I'm a bit confused on as i was going to start getting my ply sized down and sealing with the epoxy.

I have a 2" transom gap.

But if one uses 3/4 that's 2 layers of 3/4 (or 23/32nd), that's still a bit over 1/2 inch to make up. If my goo is troweled at 1/4 inch between sheets is that going to typically compress down to an 1/8 or 1/16th?

I guess i'm wondering is a 2" transom 2*3/4 then you essentially have 3 goo layers making up the ~1/2 inch difference, or should i be looking at needing a 1/4 or 1/2 inch sheet in addition to the rest?

2*3/4 there is plenty of room left over, with an additional 1/2 inch sheet i'm thinking I may need to plane it down a bit, math wise a 1/4 inch seems like what else I'd need but I'm unsure how thick epoxy layers typically are.

[swade]

Neil, sorry i'm not familiar with SBC, just had to google it sphere core. But on this budget type boat i'm just going to go traditional material. The rest will be rotted before this goes and i don't intend on going too much further down the rabbit hole on this one.