West System SNAFU - HELP!

[NorfolkRagbagger]

Been working with a friend on a West System (great stuff) epoxy patch the length of the boat along the hull-to-deck seam. (37 foot sail) Job was unfilled resin and glass. Apparently the wrong pumps were used or they malfunctioned, and after curing the material is rugged but rubbery. Sanding with 40 grit along a length of 18" takes maybe an hour to get it close to right - the sanding results in little rubbery balls coming off the surface, and even at times "pulls" like setup rubber cement from the good old days. It seems mechanically sound but this is an appearance surface, and it wil be top coated. We're debating the next step. 3 options - 1) dig it out and start all over (nope), 2) sand as good as possibly, prime and paint (will paint adhere?) or, 3) sand as good as possible and do another lighter filled coat (fairing grade filler) over the low points - will the "right stuff" bond to the rubbery stuff???

Launch is in 9 days - we don't want to look like the Lower Slobobian Navy! Any experiences or recommendations for this condition? Thanks all for the great advice as always in this forum!

 

[Ross]

Tell us your confidence level in this joint of 45 knots and 10 foot seas at night.

 

[Dan H]

Grind it out and do it right.
Just get the old crap out of there and do it right. Do you really want to be worried about that joint in building seas?
Grind it out, do it right and then go sailing.
Delay your launch and do it right.

 

[sailaway78]

Ross is right on the money

This is not only an appearance item, but structural. If that joint is rubbery, it is going to flex, and at some point probably going to let go. If it lets go, I can assure you it will be under abnormal circumstances. Dig it out and start over.

 

[kenn]

Is this actually a structural repair to the hull-deck joint, or simply a cosmetic fill?

If it's structural, you have no choice but to grind it out and do over; if the epoxy mix was wrong, it will never have the full strength of properly mixed and cured epoxy.

If it's a cosmetic fill, you have more options. Have you tried carefully warming up a section of the rubbery epoxy with a heat gun, letting it cool, and then checking to see if it cured harder?

 

[NorfolkRagbagger]

Thanks ALL! I'm impressed again at the rapid response. Hasn't been an hour! (you guys are needed in the Gulf).

The vessel is a Kadey Krogen 37, built better than most countrys' battle tanks. Yep, I'd do 45 knots and 10' seas as is - we don't reef below 30 knots! This is almost completely a cosmetic job, it is not a remove and replace from anything there previously. This surface had 1/2-round moldings at this location, had very minor leaks, removed moldings and this is more of a "fairing-in" between hull and deck - 8" below upper deck surface.

So, not being structural, we'll try the heat gun test and go from there. I still wonder about the coating/bonding between the current result and more properly mixed resin.

Thanks again!

 

[Kevin3447]

Call West - they're very helpful.

 

[Ross]

If all that you needed to achieve was stopping some minor leaks then why go to so much effort?
As Paul Harvey would say, And now the rest of the story.
My guess is that you are grossly under canvased at ten knots or even fifteen if you can sail full and by at thirty.

 

[caguy]

I have a feeling that you should be using a sealer that is flexible. When that gel coat hardens it seems to me that it will likely crack if used as a filler.
I'm going through the same process right now with the Luger30. I removed most of the silicone and 4200 that was loose. The deck joints are overlapped and screwed together every 8'' with an aluminum rub rail. I plan on disk sanding out the remaining silicone so the new one will stick. I also want to make sure that the new boat stripe paint sticks to the hull but to do that all of the silicone needs to be removed. Fortunately they only filled about a 1/4'' up the joint. There is room for almost 2'' deep. The new sealer should find some fresh glass to bond to.
Question I have is do I use silicone again or 4200. The old silicone actually looks like it held up better than the 4200 (guessing its 4200) they use. The second layer that looks like 4200 shrank and cracked in spots.
Cleaning that gap out is labor intensive and I don't want to do it again come 27 years form now.

 

[KD3PC]

you apparently used or reused dirty containers or ones that loose their coating in the mix. At least that is what I found when the West did that.

I start with clean (actually I use the plastic containers that deli meats come in) containers and you have to use the right pump for the right west product, they are marked. Full pumps of each.

Clean surfaces, no wax, no dirt, dust, etc...no caulk either as many of them will soften or react with the West. When the first coat sets, WASH it thoroughly or that too, may cause the next coat to NOT set properly. There are time limits to working with it, and to recoat or not.

Their support people are the best, and are quite knowledgeable and helpful. One of the best products/support out there, bar none.

dave

 

[kenn]

Slight derail...

I have a feeling that you should be using a sealer that is flexible. When that gel coat hardens it seems to me that it will likely crack if used as a filler.

I'm going through the same process right now with the Luger30. I removed most of the silicone and 4200 that was loose.

... The old silicone actually looks like it held up better than the 4200 (guessing its 4200) they use. The second layer that looks like 4200 shrank and cracked in spots.

... Cleaning that gap out is labor intensive and I don't want to do it again come 27 years form now.

Two things:

- I used 4200 to caulk the joint between a teak rubrail and the hull, about 3 years ago, and it now looks like hell - cracked, detached in spots, dry and chalky. Um, should a marine sealant behave that poorly? Is there a better sealant for deck use that adheres better and can withstand the sun?

- Based on the above, I think I side with the original poster... if there's something cosmetic to fix and the area doesn't flex or twist, fill it with epoxy or polyester resin, fair it, top with gelcoat or paint and forget about it.

 

[woodster]

Two things:

- I used 4200 to caulk the joint between a teak rubrail and the hull, about 3 years ago, and it now looks like hell - cracked, detached in spots, dry and chalky. Um, should a marine sealant behave that poorly? Is there a better sealant for deck use that adheres better and can withstand the sun?

- Based on the above, I think I side with the original poster... if there's something cosmetic to fix and the area doesn't flex or twist, fill it with epoxy or polyester resin, fair it, top with gelcoat or paint and forget about it.

i think the trend now is to use that gray butl tape that is used on the pre enginered buldings in the seems of the lap joints ...it never gets hard and is plyable ...i used it for years in the constructoin industry and i know if applyed correctly 99.97 percent of the time never gives any trouble....when it did it was usually installer error.....

regards

woody

 

[Paul356]

Call WEST and get some real advice.

 

[kenn]

i think the trend now is to use that gray butl tape that is used on the pre enginered buldings in the seems of the lap joints ...it never gets hard and is plyable

Since reading MaineSail's article on butyl, I've been using it for sealing all our deck-mounted stuff. No question it's da bomb for that application.

But the situation I'm complaining about, was different - it was an exposed bead of caulk to cover the gap between the teak rubrail and the deck lip. Butyl would be a sticky dirty mess in this application.

 

[BobM]

I just used butyl tape to surface mount two bathroom sinks this morning. Worked like a charm. Regarding epoxy, I can feel your pain as I had some special epoxy to tile a plastic wall niche (the contractor set aside a small quantity after he tiled the floor pan) and it never hardened for me even after I left a halogen work light on it for five hours. So in my experience there is no guarantee that will do a darn thing. I'd suggest calling west. Perhaps you can pain on a little hardener to at least harden the surface. If you decide to dig it out grab yourself a dremel multimaster rip-off or similar vibratory tool for $100 and you will move right through the job.

Good luck

 

[druid]

This has happened to me a few times. For whatever reason, the epoxy didn't kick fully (in my case it's usually because I didn't mix it well enough). It's a REAL mess to try to get off, since it's partially kicked so it sticks like a bugger. What usually works is heat - since your job is too big for an electric heater, try a hair-dryer. It may take quite a while, but if you do get it to kick fully, it will be as good as any epoxy.

Unlike poly resin, adding more catalyst (or in the case of epoxy, hardener) doesn't help

druid

 

[Snotter]

There are some jobs I am just not willing to do anymore. Grinding out half-kicked goo is one of them. Paint the half kicked stuff with well mixed epoxy and hope she don't sink.

 

[caguy]

Perhaps a name change is in order, Snotter.

There are some jobs I am just not willing to do anymore. Grinding out half-kicked goo is one of them.

Getting the old stuff out isn't even half the battle. Cleaning the surface so the new stuff sticks is what is time consuming. The Multimate tool didn't help on the silicone it just jiggles it back and forth. It does work on sanding out the contaminated surface. The tool that worked the best was a good old fashion scraper.

 

[mellis]

Use caution when sanding

For a sanding job that extensive make sure you are adequately protected from exposure to the partially cured epoxy dust. After working occasionally with West System epoxy for years, I spent the better part of a day sanding and fairing a repaired transom and keel area of an old dinghy. I was wearing a good mask, but the rest of my face and neck was exposed. Within 24 hours I was experiencing extreme itching and within 48 considerable welting and swelling in the face and neck area. I also got a bad rash around my waist where the dust must have settled inside my belt line. I apparently experienced a severe allergic reaction to the epoxy, not as uncommon as I would have thought. That was six weeks ago and I am still experiencing effects. It took an injection of prednisone to bring it under control. But once, sensitized, you are pretty much always going to be sensitized. An allergic reaction to epoxy has ended many boat builder's careers.

 

[Ross]

Re: Use caution when sanding

The very few times that I have had to deal with soft resin/glass laminate I found that a sharp chisel was most effective. Just don't use the ones that you used for joinery.