Getting ready to install deck hardware, what is the pros and cons of using butyl tape over silicon ?
We had a sailboat that had the worst caulk job I've ever seen. Chasing leaks, the PO had simply squirted a bead of silicone around the exterior seams of every fitting on deck and around the entire perimeter of the deck where it abutted the toe rail. And despite what he must have thought was an impenetrable water barrier, it still leaked. A child would have known better.
It took a long to get the bulk of it off and the surfaces never were entirely free of a greasy film that prevented anything from adhering to the fiberglass. Ultimately, I ripped everything off the boat above the waterline--including the teak toe rail and vinyl rub rail--and rebedded properly with Sikaflex. If I'd known about butyl tape back then, I'd have used it; all of the above-water-line fittings on the Defever are getting butyl.
To me, the choice between silicone and butyl for bedding fittings is the same as choosing between brandy or diesel for an after dinner drink.
Your point is actually the same as mine with a different conclusion. It is the prep not the caulk that makes the job. I'm sure that if the person who squeezed silicone all over the boat had chosen 5200 or butyl, the result would have been exactly the same.
Bruce
While inept prep was clearly a problem in my example, I would not use silicone anywhere on my boat. If I had to rebed a fitting bedded with silicone, I'd be stuck with using silicone again (or potentially not stuck being the bigger issue).
Again,
Prep is everything! I've successfully re-bedded hardware that was originally installed with silicone with other caulks.
Not sure why I argue these things in places like this. It gets me nowhere...
Ok, no silicone, ever, ever, ever.
There!
Bruce
Certainly not asking you to agree. It's your boat . . .
When I mount hardware I always bevel the hole to leave space for sealant
I would consider this a 'best practice' because it also reduces the chances of cracking gelcoat. Once the gelcoat cracks, it can act like a crack in windshield and start 'running'. The same reason why you would want to radius all corners when cutting.
Even silicone won't stick to silicone without chemical or mechanical removal...If you go through the work of prep I'd use anything else the rod time...Well maybe not okra???While inept prep was clearly a problem in my example, I would not use silicone anywhere on my boat. If I had to rebed a fitting bedded with silicone, I'd be stuck with using silicone again (or potentially not stuck being the bigger issue).
Even silicone won't stick to silicone without chemical or mechanical removal...If you go through the work of prep I'd use anything else the rod time...Well maybe not okra???
Is the 3M products, 4000-4200-5200 not silicon ???? 4000 is product I was thinking of using.
Again,
Prep is everything! I've successfully re-bedded hardware that was originally installed with silicone with other caulks.
Not sure why I argue these things in places like this. It gets me nowhere...
Ok, no silicone, ever, ever, ever.
There!
Bruce