5200 bottom

[rideaubill]

Hi all:

well after a complete summer of rain and cool temps I have stripped all my topside and stained the entire 26ft utility craft of mine, and ready to varnish..as long as the rain stops!!

next peice of business is the bottom. The hull is in quite good condition (double hull) stray cauking here and there, does require some after it is swelled. not soft anywhere but lots of flaking paint.

So after hearing this and hearing that..I come to the pro's...
Do I just strip, prime and paint...and do the swelling etc each year, or is there merit in a 5200 bottom, of an epoxy westsystem bottom.

The boat is a 1959 Andress (built Rockport Ont. Canada) 1000 islands utility.

An suggestions and methods would be so wonderful!!!

Bill

[cameron.d.mm]

Bill,

I don't have any useful advice for you on this subject, but I feel the need to post here anyway. I just drove through Kemptville this evening looking at houses for sale (there is a nice looking one just down the road from you), and my wife and I noticed your boat in the drive way. Her comment was something along the lines of, "Nice boat!".

So, imagine my surprise at sitting down to read the forums and... There it was again! It looks like it is in great shape over all, and I hope you get it up and cruising again soon. Always nice to see Ontario built wooden boats.

Question for you: will you launch it at the Provincial park down the way?

Anyway, sorry to hijack your thread and be a creepy net stalker. All the best with the boat!

[alan white]

Chris Crafts with double bottoms have fore and aft planking over diagonal inner planking, and were built with a cotton cloth bedded in either white lead or paint, I forget. This may be similar to what you've got.
Any case, the popular fix nowadays is replacement of the inner diagonal layer with 1/4 or (in larger sizes like yours, I'd go with 3/8") plywood. This is plastered with #5200 as each bottom plank is screwed back on.
It's wise to stay away from epoxies where bottom planking is concerned. You want it to take up each season, and further, find a spot to store the boat that's not paved or gravelled. Plain dirt is the way to go.
It would be a cinch to cover the bottom with plywood/glass/epoxy and be done with it. However, you may want to keep the hull closer to original, and frankly, the #5200 fix will probably outlast you. if correctly done. Replace any bad bottom planks with Honuras, Luan (Phillipine), or Spanish Cedar.

[rideaubill]

Bill,

I don't have any useful advice for you on this subject, but I feel the need to post here anyway. I just drove through Kemptville this evening looking at houses for sale (there is a nice looking one just down the road from you), and my wife and I noticed your boat in the drive way. Her comment was something along the lines of, "Nice boat!".

So, imagine my surprise at sitting down to read the forums and... There it was again! It looks like it is in great shape over all, and I hope you get it up and cruising again soon. Always nice to see Ontario built wooden boats.

Question for you: will you launch it at the Provincial park down the way?

Anyway, sorry to hijack your thread and be a creepy net stalker. All the best with the boat!

WHAT A STRANGE SMALL WORLD...I KNOW THE HOUSE YOU ARE LOOKING AT..

Will email you from my private account..

[rideaubill]

Chris Crafts with double bottoms have fore and aft planking over diagonal inner planking, and were built with a cotton cloth bedded in either white lead or paint, I forget. This may be similar to what you've got.
Any case, the popular fix nowadays is replacement of the inner diagonal layer with 1/4 or (in larger sizes like yours, I'd go with 3/8") plywood. This is plastered with #5200 as each bottom plank is screwed back on.
It's wise to stay away from epoxies where bottom planking is concerned. You want it to take up each season, and further, find a spot to store the boat that's not paved or gravelled. Plain dirt is the way to go.
It would be a cinch to cover the bottom with plywood/glass/epoxy and be done with it. However, you may want to keep the hull closer to original, and frankly, the #5200 fix will probably outlast you. if correctly done. Replace any bad bottom planks with Honuras, Luan (Phillipine), or Spanish Cedar.

My bottom is actually in quite good condition...maybe I should just scrape, paint and caulk where it doesn't swell properly and call it a day until I have a problem..then go through this drastic nasty process??

[alan white]

Absolutely. My rsponse came from the assumption you meant the bottom was to be redone, based on the terminology, where, when they say, "I think I should #5200 the bottom", it means the big procedure described.
There are seam caulks of polyurethane or polysulphide you can buy that will do the job. If you have leaks that don't swell tight you are bound to have to deal with them eventually, but for now you can caulk. Be sensitive to the fact that the seam compound must remain soft enough to squeeze out when the planks swell, otherwise the swelling planks have nowhere to go and will be ever harder to keep tight later, having crushed edges.
The replacement of an old double bottom is somewhat inevitable given the life expectancy of the canvas membrane, but it can always be put off for a while.

[rideaubill]

Absolutely. My rsponse came from the assumption you meant the bottom was to be redone, based on the terminology, where, when they say, "I think I should #5200 the bottom", it means the big procedure described.
There are seam caulks of polyurethane or polysulphide you can buy that will do the job. If you have leaks that don't swell tight you are bound to have to deal with them eventually, but for now you can caulk. Be sensitive to the fact that the seam compound must remain soft enough to squeeze out when the planks swell, otherwise the swelling planks have nowhere to go and will be ever harder to keep tight later, having crushed edges.
The replacement of an old double bottom is somewhat inevitable given the life expectancy of the canvas membrane, but it can always be put off for a while.

Thanks Alan,
I have dealt with smaller wooden boats many times from dingy's to canoes but this is my first double hull, I hear about westsystem bottoms, 5200 bottoms, so say yah others say nay..just hard to tell what is science, and is witchcraft. I will be using the boat in water for an entire season so likely swelling and sikoflex is good? Stupid question but do you paint then caulk? I would imagine so..Looking to go back to it's original copper bottom. Would I be best to completely strip the hull or just remove anything loose and re paint??

[alan white]

There are lots of formulations, so use one suited to the purpose according to the manufacturer (not witchcraft).
You paint the caulk.
If existing paint is sound, it's more protection at worst. You know its okay if it is as hard to remove as perfect paint. Only you know what degree you should go to, since you can (or have to) stop somewhere, unless doing a total rebuild. Use common sense. Thiunk of short, mid-term, and long term restoration goals, and comprimise accordingly.

[rideaubill]

Thanks!! Existing paint is not bad..I have scrapped so already..do need to do more, however the hull pic I posted is the reality of it..

one more stupid question and I'll leave you be :)
Should I caulk everything and let it squeeze out after swelling ..then paint?
or what is a typical process, I have heard the easiest way to swell the hull is to run water in the bilge?

[PAR]

Have you determined what type of construction method is used on this boat? Is it a double plank or carvel build?

As a rule, epoxy or 5200 bottoms, pretty much insure the next repair on the bottom planking will require replacement. In other words, once you glue those planks down, they're married to that location and removal will damage them beyond repair, not to mention what ever they are glued to.

As a point of note, if you're going to leave the boat in the water for a season or extended amounts of time, then 5200 or other polyurethane base adhesive/sealants wouldn't be a good choice. In these cases you want polysulfide (3M 101 or similar). Polysulfide will generally permit you to remove the planking if repairs need to be made, without damage to the planking or it's contact areas.

A boat is design to keep water out, not hold water in. If you want to find out how strong your planking and other structural elements are fastened, then fill the bilge with water, because it will test the pull out strength of each, as things swell and accept the burden, of hundreds of pounds of water in the bilge.

Run a scraper across ever square inch of bottom. Only then will you know the true condition of the paint.

[rideaubill]

The hull is double planked. I have had a fair bit of water in it at one time, some leaks along some seams and along parts of the keel.

Again I tend to think caulk and paint but not something I have great knowledge in..Do I "test swell" it before going on? Boat has been out of the water 2 years now.

[alan white]

If the hull is double planked, the inner layer should be visible inside the bilge as different from the lay of the outer planks. The planking could be diagonal or offset to the outer layer. You might see the remnants of the cloth sheathing between. It won't be intact.
It's true the #5200 bottom won't come off without destruction, but the method is common and is a value-increaser according to the selling market. I am not saying I disagree with PAR, only that the usage of #5200 is what will keep popping up in ads by professional rebuilders and private sellers as well.
I think I would also go with polysulphide for removal in case of a bad grounding, for example. The repair would be orders of magnitude easier.

[PAR]

5200 bottoms, done by professionals are usually in name only. Even if polyurethane is employed it's usually not 3M. Most are now realizing they need to use polysulfide, possibly after trying to repair 5200 bottoms or seeing 5200 pull right out of the water soaked seams, in long rubbery strings. A reasonable professional, performs work that can receive future repairs as well.

If your boat is leaking, it very probable it's not the seams on a double planked hull. This is where the water is getting in and the rabbit may be in question (which is typically a single plank, not doubled), but the usual suspect is fasteners, not seam goo.

In other words, before you toss a bounce of money and effort at your boat for things it doesn't need, you should have it accessed professionally.

[The copper guy]

Canvas and boild linseed oil for the sandwitch.
Copper on the bottom back as she was, That is why she has lasted so long
you canot improve on the old way.
I dont know if this is ok but look at this if you can
http://copperaboatbottom.webs.com/ -
ALL THE BEST TOM

[gonzo]

5200 is not the best choice for below the waterlind caulk. A two part polysulfamide well primed is the best choice. It means cleaning the seams to bare wood.

[Aquamagi]

I built a modified reproduction Chris Craft with cold molding (triple bottom and double topsides) twin engines. All with epoxy glue. All with mahogany solid and okume ply. Everything is solid except the white oak keel where the bottom is separating from the oak rabit at the keel and thru the two piece oak keel. The fasteners are all stainless and solid. I used 5200 to glue the four large Philipine mahogany engine bearers in place (no fasteners) and also in a 5/8 " thick pad under each of the eight engine mounts (no fasteners either from the mounts to the bearers). The boat was launched in 2003 and in water used all summer in 03, 04 and 05, then out on stands in 06,07, and 08 and back in water for 09 and 2010 summer. There are absolutely no problems with the 5200 joints holding the bearers to the ribs or under the engine mounts. I'm tempted to open the bad seems up and use 5200. Do you think polysulphide would be better, and if so, why? and what kind of polysulphide?

[mydauphin]

I wonder if painting the bottom of fiberglass boat with 5200 as a barrier coat would be a good idea. Then you paint bottom paint over it... Should be indestructible.

[alan white]

Cost compared to epoxy? Assuming, that is, that 5200 is as impermeable as epoxy. Ease of application? Longevity? What about toughness (beaching, etc.)? And if scraped, while epoxy only would scrape off to a certain depth, would 5200 scrape off in such a way that it tears out a larger gouge because it stretches before tearing?

[PAR]

3M 5200 is a miserable adhesive compared to epoxy and your engines and shafts will eventually suffer from the lack of fasteners, which insuring alignment and the sure to stretch out high modulus of elasticity of the polyurethane.

It's difficult to comment on practices like this or the longevity of these types of practices. 3M 5200 is designed as an aggressive sealant and shouldn't be remotely considered in the same class as an adhesive like epoxy. Yes, it has good adhesive qualities, but also permits considerable movement and distortion, both of which are foolish in engine bearers, mounts and other structural elements, where locking down the structural piece is the paramount consideration.

Why you planking is separating from your keel is also a crap shoot. 3M 5200 is a very poor underwater seam sealant, unless it's applied and immediately placed under pressure for a few weeks. If you just pack it into a seam, once the wood get wet, it'll pull out like a big rubbery string. Polysulfide would be a better choice as it'll cling to wet wood, though it should also be applied under pressure for best performance. 3M 101 is the typical single part choice for this goo.

The planking is held in the rabbit by the frames, which are held to the keel by the floors. If you used 3M 5200 in any of these interfaces, then this is the reason your planking is backing out of the rabbit. If this is all fastened and epoxied, then you have other issues, but without pictures and an idea what make and model repro you built, speculation past this would be guess work.

[Aquamagi]

Thanks for your comments Par. Its clear from this and other of your posts that you are not a big fan of 5200. I'm still on the fence about using it on the previously epoxied seems that have opened up at the keel and rabbit. I understand your concern about my using it on the engine bearers and engine mounts but I must say those are two places where there have been no problems at all. Also this is the end of the eighth year after launch and there are no shaft alignment problems. Everyone I've spoken to has said my problem was using the epoxy on the white oak. It simply cracked with the working of the boat and the vibration of these two big engines. The boat is upside down now and the plan I'm considering is:

1) rout out a rectangular trench on the outside of the botom down the center of the keel approx 1/2" deep by 3" wide (1/2" wider than the two white oak keel pieces). Avoid all fasteners. The keel pieces are 6" deep.

2) completely clean out the opened seems (circular saw or router etc.) down 1 to 3 inches below the bottom of the trench, by 1/8th to 1/4 inch wide.

3) soak the trench and cleaned out seems with CPES, let it get tacky

4) pack filler into the seems below bottom of trench and coat the bottom and sides of trench with filler

5) cover with a new piece of mahogany previously treated with CEPS that will fit into the trench maybe protrude proud of the bottom like a long shallow keel.

6) fasten the new piece with stainless screws into the white oak thus putting the filler under pressure.

7) coat entire repair with 2 to 3 coats of epoxy and good coat of antifouling bottom paint.

I'ld really love to hear what you think about this plan.

Hans

[gonzo]

5200 will separate from wet wood. Polysulfide needs to be primed for good adhesion.

[PAR]

I have no advise for people using CPES and 3M 5200 in the fashion you have. There's plenty of documentation , testing and research to back up my "beliefs". The same can be said about white oak and epoxy. I've said for years it works, with proper preparation and now West System's own testing verifies what I've been doing for over two decades.

I'm not sure where you're getting your information, but you're using these products correctly and this is why you are having failures. I've glued white oak for decades with epoxy without a single glue related failure. I've stop using penetrating epoxy for some number of years and testing by the major epoxy formulator reinforces my reasons for stoppage.

[Aquamagi]

I have not yet used it for the problem on the bottom. What would you suggest.

[Aquamagi]

what do you suggest for a primer?