which caulk is best (silicone or polyurethane) for trim?

[S. Heisley]

5200. It may squish out a bit, depending on how much you use. You want a good seal. Just keep a rag or some paper towels handy and dampen them with a little paint thinner or mineral spirits and wipe off the excess caulk before it dries. (I wish I'd known that trick when I first started using the stuff...I was using dry paper towels. Mineral spirit-dampened ones work slick!) If you are getting the one that's used in the caulking gun, the tip unscrews for cleaning. Clean it before it hardens.

I don't know how much you're doing; so, you'll need to calculate that out. I think the container says on it how much it will cover.

[LDK]

5200. It may squish out a bit, depending on how much you use. You want a good seal. Just keep a rag or some paper towels handy and dampen them with a little paint thinner or mineral spirits and wipe off the excess caulk before it dries. (I wish I'd known that trick when I first started using the stuff...I was using dry paper towels. Mineral spirit-dampened ones work slick!) If you are getting the one that's used in the caulking gun, the tip unscrews for cleaning. Clean it before it hardens.

I don't know how much you're doing; so, you'll need to calculate that out. I think the container says on it how much it will cover.

Hey Sharon

I went ahead and ordered some on line. I'm getting the white 4200 fast cure. It's the general purpose kind but is still waterproof. I just ordered one tube and I'll use it for the trim and screw holes. If I happen to have enough left I'll use it around the windows and roof vent, if not enough I'll use butyl tape instead.

[streetrod23]

Sika flex is a product used on semi trailers that get a lot of flex and punishment. ( urathane base) It was recomended to me by Carry at Camp-In. I just cant remember the exact number but if you google it they list the products. It is easier to work with that silicone and lasts longer...Semi repair shops sell it in our area

[eamarquardt]

I wouldn't recommend using 3M 5200 if you EVER might want to disassemble what you've put together with it. I once had to remove a port light in my boat that had been put in with 5200 and it looked like a pretzel before I got it off. The only good news is that it was under warranty and the builder knew it couldn't be removed without destroying it and provided me with a new port light.

Cheers,

Gus

[madjack]

...think of 3M 4200 as a removable version of 5200(sorta)...the SIKA-FLEX product is 221...I think and is an excellent product if you can find it......
madjack