Polyurethane vs. silicone

[chuckster]

Has anybody out there used polyurethane sealant/ adhesive instead of silicone? I've done a lot of work on boats, and we call silicone, "Satan in a tube". I'm going to use polyurethane, regardless, but I was wondering if anyone had opinions, positive or negative. Thanks, Charlie.

[flynntuna]

Found this on the inter webs....

https://www.hunker.com/13414953/polyurethane-vs-silicone

And this....http://www.adhesives.org/resources/knowledge-center/asctv-single/bond-strength-polyurethane-adhesives-vs.-modified-silicone-adhesives

[Doug @ Forma]

We use ChemLink M1 adhesive/sealant on all of our builds. Very strong but remains elastic after cured. Much better than silicone.

It's available on our web store:

https://www.formacars.com/store/chemlinkm1

[Mark Reynolds]

I highly prefer urethane. I'm sure the above offered by Forma is fine.
Breeze had been offering Bostik 1100 for years now and I think it should be the default panel adhesive.
http://www.breezeautomotive.com/details.php?prod_id=1180
I also use it all over the house. The gray happens to match the color of my house EXACTLY and for this house paint job I used it to seal the edges of the clapboards to the trim to prevent water from getting to the bare end-grain of the clapboards. I used it just today to seal the joints on replacement trim board sections I installed when cutting out rotted sections. I've used the black to seal cracks in the driveway. I also must give a shout out to Sikaflex which a boating friend gave to me because he accidentally bought a tube of black when he meant to get white. I used it to bond and seal some aluminum rust repair panels on my 1999 van.
It also worked great and like the Bostik I really liked the way it handles and sticks.
BTW the info on "hunker" linked above is useless. The demo on adhesives.org give a nice proof on the bonding strength advantage of (poly)urethane over silicone.

[Chris @ Forma]

Mark,

The material that we use is in fact a urethane chemistry. We use it in another part of our business to adhere aluminum sheet metal components to aluminum sand castings. While silicone is an excellent sealant, it is a very pore adhesive. In our other business where we use the M-1, and have to disassemble the parts after the adhesive has fully cured, we destroy the sheet metal sometimes tearing the aluminum before the adhesive fails. We have contemplated assembling a build without rivets as the aren't nearly as strong as the adhesive, however, the adhesive is applied to the FFR powder coated chassis and their paint bond strength is always suspect.

Anyway the M-1 works flawlessly. My only criticism of this material is that no matter how careful you are you end up with it where you don't want it. Usually on my clothes and it doesn't ever wash out.

Chris

[flynntuna]

Who wants to be the first to test flex-glue?

https://www.flexsealproducts.com/product/flex-glue/