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For devotees of butyl rubber as a sealant

Started by brackish, October 23, 2019, 07:03:53 AM

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brackish

The last refit I did, a little over two years ago I removed all the teak for refinishing and when I put it back decided to bed it all with butyl rubber, the first time I had ever used it.  Yesterday I was at the boat and noticed four leaks at the site of the two screws each that hold the forward grab rails on.  The rain that caused these leaks was a hard long rain, the first following a six week very hot late summer drought.

So thoughts about this:

Does butyl rubber require periodic reset by turning, in this case, the acorn nuts a half turn or so?
Is it possible that the long drought caused the wood to dry enough that it shrunk away from the seal?
Any other possible thoughts?

bruce

No first-hand experience, my boat is dry sailed under cover, but I did read this just yesterday. Might be helpful.
https://marinehowto.com/bed-it-tape/

Butyl tape isn't an adhesive, and doesn't cure, but remains sticky and malleable. So, if the wood did dry out enough to open a gap, tightening the fasteners should, in theory, squeeze out more butyl.

Love the stuff to work with!
Bruce
Aroo, PC 308
Narragansett Bay, RI

slode

I have had great luck with Butyl tape sealant in many applications with long lasting waterproof seal.  There are a few tricks with fiberglass.

1. Make sure all surfaces are CLEAN and COMNPLETLY free of any old sealant.

2. Counter sink all holes through the fiberglass to give the butyl somewhere to compress into and have some body left to take up any slight movements without separating.

3.  If possible only turn the nut, hold the screw in place to avoid spinning the threads in the sealant

3. After a month or so go around and re-tighten fasteners.  It should only take one pass to re-set the hardware after the butyl takes it's initial set.

Marine how to has a pretty good article on this https://marinehowto.com/bed-it-tape/  Of course he's promoting sales of his butyl tape, but I agree with most of the points and it's the only method I'd use for bedding hardware that will someday, eventually need to be removed.
"Sylvia" 2006 Eclipse #41

Renae

Roger, the PO of my boat, swore by butyl tape.  I dry sail, but he camped onboard for weeks at a time (thanks to which I have an auto-tiller, stove and a pallet full of nifty accessories I probably won't ever use).  I didn't get to the teak this fall because going sailing always sounded more fun than rubbing Cetol, but come the spring thaw, I'll follow Roger's recommendations.