Butyl caulk or something else?

[JHZR2]

This is 10+ year old caulk, super flexible and super-well adhered (yet was able to be cleanly peeled off with a lite work). It sealed the exterior case of my through-wall AC to the aluminum siding.

I'm wondering if it is butyl or polyurethane? It filled a wide gap without any backer, stayed clean living outdoors, and kept real flexible.

Any ideas? What would I want to use and who is the best manufacturer/product? Where is the best place to buy???

 

[Drew99GT]

I personally have had the best luck with GE silicon caulks, but make sure the tubes you buy aren't expired.

 

[Warstud]

Looks like urethane and that's what you want for that application.

 

[AandPDan]

Looks like duct seal. You can also use it around service entrances and junction boxes.

The big orange store has it. It comes in a brick.

Duct Seal

 

[tom slick]

I like Lexel for applications like that.

Lexel

 

[Texan4Life]

when i put in a new evaporator in our 90 deville, the old stuff cracked off in chunks. I used plumbers putty to redo it. still looks and is working good.

if you haven't used it before it is easy to work with. It comes in tubs of different sizes and it has the consistency of play dough.

 

[JHZR2]

Well this is a home application, and it's definitely not plumbers putty. Duct seal in the black brick could be useful but wouldn't look right.

The stuff on there was a 1"+ bead of nice smooth flexible rubbery stuff.

Sounds like that level would work and they make it in white.

 

[tom slick]

Lexel is solvent clean-up only so have plenty of rags and mineral spirits or lacquer thinner ready.

 

[JHZR2]

hmmmm.

my aluminum siding is painted. Im a bit worried about killing the paint.

I assume the lines (edges) should be taped?

 

[mechtech2]

Tape will ensure the best line. Even if you extend it out a bit more than before, a straight line in exterior work makes it very nice.
Prep is the hard work, application is easy then.

 

[andyd]

Phenoseal caulk comes in colors or clear.