storm collar caulk

[Charles2]

What type/brand of caulk is best for sealing where storm collars meet double-wall insulated stainless steel chimney pipes? Is the same material best for sealing where guy screws penetrate asphalt shingle roofs?

 

[begreen]

Don't use an asphalt product, use silicone. GE Silicone II is a good product. I've peeled it off after 8 yrs of service and it is still bonding well.

 

[TheRambler]

Most any outdoor rated caulk would work, personally i would go for the high temp stuff(rtv sealant). Whether that is needed or not i'm not certain.

 

[begreen]

Regular caulks like acrylic latex should not be used. Normal silicone is rated at about 400F. It won't get that hot on the outside of the class A at that location unless there is a serious chimney fire. In that case everything should be inspected to determine if it is still suitable for continuing service. RTV is fine, it's rated around 600F, but it's not essential here.

 

[mellow]

Just depends if you like orange or not.

 

[begreen]

Exactly. I don't like seeing a stripe around the storm collar.

 

[Charles2]

Is there no such thing as a clear, colorless RTV?

 

[HarmanManP43]

Is there no such thing as a clear, colorless RTV?

Rtv I picked up at home Depot is clear.

 

[begreen]

If that is Pro-Seal clear RTV it has the same temp rating as GE Silicone II. 400F continuous. RTV simply means room temperature vulcanizing which includes most all common silicone adhesives I think.

 

[HarmanManP43]

Rutland clear. 450 continuously 500 intermittent

 

[begreen]

That should work.

 

[Charles2]

Clear GE silicone II appears to come in 2 varieties: Kitchen & Bath and Window & Door. Is there really any difference?

 

[begreen]

I've only used the window and door. I would suspect the kitchen and bath has a mildewcide added.

edit: verified.

 

[UPswede]

Helps to wipe/clean the area to be caulked with some solvent before applying the silicone.

 

[jrems]

One trick I learned if you want a completely smooth bead of silicone, use a melting ice cube shaped to the contour you want instead of smearing it with your finger. The silicone won't stick to the melting ice cube and will have a glass smooth finish. Don't try to dry any water on the silicone from the ice cube. It won't mix with the silicone and will dry on it's own. This works great inside but maybe not outside now that it's below freezing.

 

[webby3650]

One trick I learned if you want a completely smooth bead of silicone, use a melting ice cube shaped to the contour you want instead of smearing it with your finger. The silicone won't stick to the melting ice cube and will have a glass smooth finish. Don't try to dry any water on the silicone from the ice cube. It won't mix with the silicone and will dry on it's own. This works great inside but maybe not outside now that it's below freezing.

Or just tool it with your finger and be done with it!

 

[Hogwildz]

Good ol spit on the finger worked for years for me. Tooling is a must.

 

[Charles2]

I've only used the window and door.

Which is a good call BTW, because it lists flashing on the label!

 

[Woody Stover]

For the collar, I use what I have around with my stove stuff, usually a tube of Mega Black from the auto parts store. For asphalt roof work, this is what I used recently. Even the Henry Extreme is rubberized and will hold up better than standard roof cement...