stove cement becomes useless powder

[RustyShackleford]

I decided it might be helpful (against faint smokey odor in room during slow burns) to better seal around the bottom of my stovepipe where it goes into the flange on the top of the stove (it's not perfectly round, and there's a gap of maybe 3/16" in one spot, where the circular flange is closed with a weld).

So I've used ordinary stove cement and it works against the smokey odor. But in less than a season of burning, the cement sort of degenerates into a fine powder - might as well have dumped a layer of talcum there, and I don't think it's doing much good anymore.

Is it just than the flue flange gets too hot ? Is there a different product that might work better ?

 

[bholler]

You need to use flat gasket any furnace cement you use will be pulverized by the expansion and contraction.

 

[Highbeam]

I had the same results in the same application. The dry chunks of cement loosely in the gap seal better than nothing at all though.

 

[RustyShackleford]

You need to use flat gasket any furnace cement you use will be pulverized by the expansion and contraction.

Ah, that makes sense, thanks. Just get some gasket rope of the right diameter and cram it in there.