5200

[Notorious]

My experiance with 5200 below the waterline was very bad.My 52' double planked wheeler was drydocked for 8 months while I redid the oak doublers and sister framed sixty frames. I was worried that it might not swell back up to proper tightness so I used 5200 in the seams. (Previously there was nothing but a good fit). I painted the bottom with two coats of copperlux with chyanne pepper mixed in. The boat swelled back to proper tightness and squeezed out the 5200 breaking the paint seal. The worms loved and ate the the planks from the seams in. Wrecked over a dozen planks.
I beleive that a polysulfide would be better suited as the worms won't eat it. This is from my Wheeler days back in the early days when 5200 was polyurthane.
Also a polysulfied resists oil and fuels from softening and releaseing them.
But like I said this is old experiance and should be reexamined.

[Notorious]

Oh yeah....I forgot to ask if anyone could expand on this for me.

[Bob Cleek]

Sorry to hear of your grief. Another good reason to check out the FAQ section and use the forum search engine. This sort of problem has been reported repeatedly. We've begged people not to use 5200 as anything other than a PERMANENT bedding compound (and why would you ever want a permanent bedding compound?).

[Domesticated_Mr. Know It All]

3-M 5200 is forever. :D
I wouldn't use it on anything that I might want to take apart later.
I believe it has some uses in wooden boatbuilding and restoration but it's not a fix all kind of glue.
Another thing to remember is that the wood will fail before the glue joint will.
Sharing your problems with the forum allows others to learn from your mistakes and should give you some satisfaction that you've helped someone avoid your problem.
I tip my hat to you. smile.gif

[JormaS]

What Bob said. Most people here tend to think that 5200 or any polyurethane (5200 is polyurethane) or polysulphide compound is not at all a good idea below the water line -- in my view at least not if the boat is hauled yearly or otherwise for more than a week or so. This is because the goop will let go from the wood when the planks shrink.

But your problem is that the critters actually fed on the polyurethane -- is that right? In that case polysulphide would at least have been less edible because it has some lead in it -- at least the two-part variety has. Regular lead paste would probably have been the best choice.

[carioca1232001]

I did some replanking on the bottom of my boat and used the traditional stuff, viz., linseed-oil putty (lead-free though).

I spread this on the inside plank surface and it oozed out at the seams as I fastened the plank on. Aside from anything else, it does smell good !

Was dissuaded from using polyurethane for this application by people on this Forum and by a senior(75+) boat carpenter at my club.

How right these more experienced folk were, as it was a real headache to take out some older planks that I had installed previously with polyurethane. :rolleyes:

In addition the poly stuff had shrunk and wasn´t paying the seams anymore :(

[Gary Bergman]

I'll happily go against the grain and stste that 5200 works just fine for me underwater. The worms aren't eating it as they were some older polysulfide that we reefed out this year. Before I owned the vessel, the former owner's used 5200 for 14 years of 'Canada to the CArribean' chartering with no damage attributed to the caulk, altho' the worms did like a lot of the mahogany...Many Canadian vessels that haul out yearly and sit during the winter swear by 5200.....

[Ken Hutchins]

Like so many other things everyone has a different opinion.
5200 like a lot of other materials if used the proper way is good, use it the wrong way and problems will occur. It can be successfully used as a PAYING COMPOUND in a seam OVER COTTON, not with just the 5200. Larry Pardy used this method on Taleisin and I personally asked him if he would ever use it again on another boat he said "absolutely it is better than anything else he has ever used as a paying compound, but it should only be used as a paying compound not as a replacement for cotton" I then asked him about removal for repairs and he said "no problem take a cut along each side with an exacto knife and peel it out."

[Gary Bergman]

Exactly what Larry said and Ken reiterated..My girlfriend, bless her heart, reefed the majority of 60 below waterline seams over 50' in length with a utility knife and my reefin' tool from a file....I did all the replacement cotton behind her, luv my caulkin' irons, I do!...What a fine 'stress reliever', eh?

[ErikH]

A random tip: if you ever have to remove large amounts of not-quite-rock-hard 5200 (don't ask) that scraper attachment on a Multimaster is a wondeful, wonderful, thing. I imagine the seam removal attachent would be equally good.

[carioca1232001]

Ken Hutchins wrote:


....It can be successfully used as a PAYING COMPOUND in a seam OVER COTTON, not with just the 5200...... I have used POLYURETHANE on its own - and was unimpressed by the results.

I have not used POLYURETHANE OVER COTTON - Ken Hutchins has and has been well served.

Please note that there is a substantial difference.

[T.A.R.]

If you have trouble removing 5200 from seams with a knife try a pencil fine torch. The 5200 softens and looses it's grip without tearout or damaging plank edges.