stack cap sealer

[ebliese]

Anybody have a good recommendation for a smoke stack cap sealer? Due to the way the cap fits inside the stack pipe, I believe water is running down the length of the inside of the stack and then getting on my arch. Currently I have a plastic bag over it but would like to change that. I have a single walled stack and I run a hot firebox (stack temp is between 900 and 1300 depending on conditions). I was thinking of giving the Permatex 27038 Optimum Red high Temp gasket maker a shot-750* intermittent. I don't remember the exact height of the stack (would have to check) but it is at least 8 feet.

Thanks!

[Pdiamond]

I ran the single wall stainless to the bottom of the roof. Then when I went thru I switched over to double wall stainless pipe. I purchased the double wall from menards along with the cap and the high temp peak jack. This has never had any water issues.

[ebliese]

Well, it's not the stack cap. After a rainy night with a plastic bag over the cap, water still was on the arch. I looked up the stack and couldn't see any water lines running down the inside. With the cap ruled out, it is probably the storm collar. I have the storm collar cinched down as tight as I can but there is no sealer between the collar and the stack pipe. I've tried a couple of high temp sealants but nothing will hold up to the heat so far that I have found. Any suggestions? Again, this is single walled pipe. I know I could always switch over to double walled pipe when I go through the roof (which is metal).

[nhdog]

does your roof jack have have vent holes or slots to allow heat to vent up? we have very high winds here and my sugar house is on a hill and i found during storms sometimes the rain would bouncing off the metal roof jack and splatter up under the storm shield then would be driven against the stack and run down the outside of the stack onto the arch. i used insulated stack pipe so it was easy to seal it off without causing any problem, end of problem! seems like that may be your problem or you haven't caulked the storm shield well enough.