Fountain uses a black caulk around their acrylic windshields. I always assumed it was 5200 since it is such a ***** to get off.

I read the product description of 3M 5200 and lesser strength 4200 and they both say incompatible with acrylic.

Can someone out there enlighten me on what the factory uses and what 3M means by incompatible?

Thanks

i have used both of those products in several applications and find it absolutely worthless. it takes forever to set and doesn't last worth a sht. if you are simply caulking seams there are better and more conventional ways to go. if you are making structural and meaniful sealing bonds, i would use the same urathane that is used to install automotive windshields. it is forever and impervious to everything.

I thought they used Butyl based products to do that. Something that was designed to seal but let go when needed.

I am sealing but want it to look clean & neat but be able to be removed without destroying everything.
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What They Mean By Incompatible Is That It Will Harm Or Attack Acrylic.
Acrylic Is Very Suseptable To Damage From Chemicals.
Just Good Ol' Black 50yr Silicone Will Work Fine In Most Cases.
Keep It Away From Polished Edges As It Could Harm Those Areas.
I Outline My Areas With Good Painters Tape And Install The Adhesive. Promptly Remove The Tape For A Clean Install.

i agree. i use to be in the automotive glass business and used the urethanes on many projects. it hardens quickly and is extremely stong. some urethanes to have a primer that you must use for good adhesion. just be sure and read the label on it as to whether or not a primer is needed. when it dries it has a flat/satin look to it. it actually looks like a tire finish when dries and very durable.

When I replaced my side panels, I used plain black 100% silicone caulk. I used the tape method as above with excellent results.
Really made for a clean, straight factory edge. Didn't have to worry about getting caulk all over either.