What's the best RV sealant?

Bumpyroad wrote:

westend wrote:

Ruthless wrote:
Does anyone use:

CW 221 SEALANT SIKAFLEX 10.3 OZ
or
WHT 505 SEALANT UV HV SIKAFLEX

I've used Sikaflex for construction applications. Both of the Sikaflex products you listed (227, BTW) are urethane based polymers. The first one is the most applicable for RV use but it has less elongation and tensile strength than the Geocel products. It will work but in your context of this thread, is not "the best".

gotta check my owner's manual again but I think I need a urethane type of sealant. are you indicating that the second one 505 would be preferable to the 221? I did find a 3M white sanded polyurethane caulk if anybody has any experience with that.
bumpy

From the technical data sheets, Sikaflex 227 is superior to the 505 product for RV applications. The 505 is formulated to have better adhesive bonds to different materials like stone and plastic.

For our RV's it would make sense, IMO, to have the most durable product with the best elongation and tensile strength. The Geocel tripolymer products seem to have the better ratings in those areas. There are other things to consider, though, like tooling and paint adhesion. When I'm shopping for products like these, I mine the data sheets and the MSDS to find out how they are made and what separates them from others. It's the little scientist locked inside me, I guess.:B