Butyl Tape vs Polysulfide Caulk on Rebedding

[Maine Sail]

Originally Posted by s/v Jedi

I removed a deck fitting after 15 years. The 101 wasn't cured. The only cured part was less than 1/4" on the perimeter of the fitting (where it gets in contact with moisture).

And I have been using polysulfides as along as I can remember and seen it cure in LOTS of cases. When it cures it is not easy to remove, trust me. There is not much on a boat save acrylics/polycarbonates that does not get mechanically fastened. And as we both know polysulfides should not be used on acrylics or polycarbonates..

Originally Posted by s/v Jedi

There's not many new cars with butyl sealed windscreens anymore. I wouldn't know a single one. They use high tech urethane adhesives now, I posted that before. Here's 255,000 links to demonstrate it: auto glass adhesive - Google Search

Exactly! This is why I said what I said below (see my own quote). However for over 40 years windshields were sealed with butyl. My last butyl windshield replacement was in the 90's by Portland Glass so it was not long ago that it was still being used.

Originally Posted by Maine Sail

The adhesion of butyl tape is in the neighborhood of 10-45 psi and we all know how many car windows fell out at 80 mph? None that I know of... Heck I have seen bodies fly through windshilds and not break the butyl seal and that is 10-45 PSI.. Adhesive...?

The fell out part was purposely worded to not say "how many windows fall out" because I am keenly aware that they no longer use butyl in windshield installations..

Originally Posted by s/v Jedi

I have never seen a DIY cruiser doing it anywhere near right, but they are quick to complain about Sika when it fails some time after without ever considering the problem was their application and not the product.

I once took the time to explain someone exactly how to do it. He slapped the lexan on with 5200 instead. I hope it lasts forever because it will require a lot of fiberglass work when it needs to come off....

cheers,
Nick.

Let's not just put DIY's in the "not doing it right" bucket. Boat yards, boat builders & "pro's" are just as guilty of not reading directions, getting proper training or following simple instructions.. Barrier coating is a PRIME example!

[delmarrey]

Originally Posted by schoonerdog

I'd recommend a lifeseal rather than life caulk

Correction on my part. It is LifeSeal® that I've been using, not LifeChaulk®, both a product of BoatLife®. LifeChaulk is more suited for teak and other woods to fiberglass/gelcoat.

Gett'n older can't remember the names of stuff. (sometimers disease)

[delmarrey]

I think there maybe some confusion between sealing windows (the see thru part) and the window frames. Frames are a whole different story then just glass/plastic. Frames are usually metal or plastic (alum, bronze, SS or gold ) and have different holding factors.

All applications may have different situations, which would require different bonding methods. So what's great in one situation may leak in another. One just has to try different methods until one works.

If I had frames on mine I probably would have used 3M 101, unless they leaked, then it would have been back to butyl tape! But to me is doesn't matter, they are all work to get off. And I want a good seal for at least a few years.

[Extemporaneous]

Info from Tremco on Plastics.

Regards,
Extemp.

[clearsea]

I love butyl, but it is unbelievable how little bits of excess butyl tape end up here and there on the deck to make little dark blotches, no matter how scrupulous I am. It always comes off with gentle rubbing with a finger or cloth. I never use a solvent on it.