caulk preference

May 29, 2007 18 Replies

For caulking pine exterior of 2x8s after staining is silicone or Lexel preferred?



What are you caulking? Is this exterior trim or what? At any rate, I definitely wouldn't use Silicone. I'd use a one part urethane caulk designed for windows and siding. Here is what we are currently using:

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exterior trim and cracks in siding

I agree with Marson. I have dealt with many silicone failures. I believe in urethanes and Dow Corning 795 if you insist on silicone.

Does that include the exterior grade rated silicone caulks in that, or just interior grades used on the exterior?

Dennis,

I don't know what kind of silicone someone used before I got involved. When I can grab one end of a silicone bead and pull it out of the joint without breaking it, it tells me it was not adhered to either surface. Try that with a bead of NP1 or equivalent single part urethane.

Silicone is very sensitive to different types on different substrates and will usually require priming. The NP of NP1 stands for No Prime.

Look for a product called Vulcum. It's the best I have ever used!

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Thanks for the spelling correction. I was too lazy to walk out to the shop and check the tubes.

I like it! Have fixed 2 cracked boats with it that are still water tight 15 years later. One alumium and one wood.

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