Sikaflex 721 on roof?

[Devoman]

Anyone use Sikaflex 721 UV on anything.I am wanting to replace some sealant on the roof.The sun has finally caught up with it all.
Would the 221 be just as good though.Seems the 721 UV might last longer but never used it before.

[kevinb]

If it is going to be exposed to uv 221 is a no go. I love 221 but have never worked w/721 I was told you have to order it in lg quantities. I suspect from an application standpoint not much difference. From what I have READ look into dicor, butyl tape or tremco 636 depending on the application for alternatives.
kevin

[jm2]

most commercial distributors offer this product only in case quantity (24).

you can find the '721 product here in white, grey, and black, in quantity 1, or more. - https://store.airstream.com/product_...roducts_id=316

stick with the 721 rather than the 221. the 721 will last longer.

here's some links you might find useful.

http://www.wbcci.org/documents/Schus...ber%202007.pdf

http://www.wbcci.org/documents/Schus...Nov%202005.pdf

http://service.airstream.com/files/l...8f65c7c167.pdf

Airstream, Inc :: How To and Diagrams

best,

[John Shea]

Hello, Just curious what you ended up going with and how it worked?
Thanks!

[n2916s]

Originally Posted by John Shea

Hello, Just curious what you ended up going with and how it worked?
Thanks!

John,

You are replying to a post from 2010. If you Google sealants:Airforums, you should get lots of up0 to date information. Look especially for a topic called something like ‘sealants summary”.

[jokila]

Based on everything I have searched and in the year 2021, I am going to use Sikaflex 505UV for roof sealant on my Excella. The 721 version has been discontinued by the Silka.

It's also available at Camping World, Amazon, and ebay, and I am sure a lot of other resellers.