Wharf Rat 1

I tried doing a "search", but there were soo many threads with the word exhaust in them. I'm looking to install tips. I saw someplace, don't know where, you put a layer of something on the transom before you put the tips in. It was "grey" in color. Anyway, what do I use as a waterproof sealer? I think 4200 is too much of an adhesive. Can I use regular silicone?? Thanks...

boatnt

I would stick with the 4200,,

Griff

Marine rated silicone, 4200 or 3000UV. All will work fine and have about the same adhesive strength
http://multimedia.3m.com/mws/media/8...t-brochure.pdf

sonicss42

Also if you are making new holes be sure to seal the exposed wood core with some resin/epoxy. Just sealing the flange is not enough protection.

madbouyz

Exhaust tips don't need any adhesive strength in the sealing material . I'd avoid both 4200 and it's evil sister and use a siliconized polysulfide or pure polysulfide from Lifecaulk . Actually 3M makes it as well but I can't recall the number of it .

At some point down the road I want to remove my tips and clean up the seat on the transom exterior. I remember the engine installer saying a long time ago that he used 5200 on them
If I find that's true I'm going to hunt him down and string him up by the ****s

Wharf Rat 1

Thanks guy's. I think I will go with the 3m marine silicone.

class6

I use 5200 on everything that could come in contact with water. I prep for the long run not the repair or clean up. Once you learn how to deal with removing a part with 5200. It's not a big deal. I never want to wonder if it's still good. I'm not telling you what to do. Just telling you what I do.

madbouyz

To be honest , I've never tried using any of the 5200 de-bonding sprays , or whatever they are. Every time I've seen 5200 used it turns out to be a big PITA for the next guy , even if the next guy is still the current owner . I don't even use it below the waterline any more .
Some years back a fiberglass fabricator out here decided to test it by laminating two pieces of new transom cut out sections together that he had made . Chains attached to fork lifts on either sides through bolted to the laminate and an intense pull and the fiberglass and marine ply shattered but the 5200 didn't let go of the surfaces they were stuck to.
Who needs that for installing cleats and through hulls ? Not me .

Furthermore silicone is an invention of the 60's It was a miracle when it came out but it's been far , far surpassed now by materials like those I mention in my 1st post.
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