Tin Foil

[TwinBay]

What is the best stuff to use to prevent the smoke within my concrete arch from seeping up around the pans?
Hard time finding insulating material.
My default for now has been Tinfoil ???

Thanks in advance.

[MAsteveINE]

I get stove and furnace cement ready to use in small containers at my local hardware store,

this time of year make a bit of fire just to take the chill out of the rigging and then fill cracks and gaps

generously with the cement, then bring up the fire slowly and the patch will harden like mortar.

MAsteveINE

[TwinBay]

Good idea=
What I really need is some tpe of easy to acquire gasket to prevent the combustion gases from leaking out the top around the small gaps with the pans.
I have a 2x8 concrete block base with a 7" twelve foot stack, a 2x4 pan and then two hotel pans as preheaters lined up.
As soon as the blower gets turned on even at low speed, the smoke comes out....

[mike z]

I think if your stack was taller it would draw more, course that would bring you back to the plugging gaps question, as you would not want cold air coming in around the pans. I'm going to try 2" rail gasket this year on mine. That could work in your case.