Acid From Coal Burning

The photo is a steel chimney thimble after 25 years of coal burning, this was just replaced with a stainless steel thimble before this years fire was started. Even thought the chimney, stove, pipes and thimble were religiously cleaned every spring the residue from coal burning combined with humidity and summer rain eventually took their toll. We used Rutland stove mortar to set the stainless thimble in place inside the chimney.
We have been using a Colebrookdale Severn for our coal burner the entire time, we still have all the original grate pieces none are warped or damaged. When we purchased this stove the dealer said the quickest way to damage a coal stove is to let the ashes build up to the grates. We have replaced glass in one of the doors, and rope gaskets about every 3 years. Burn 3 to 4 tons per year nut or stove both burn well.

I'd say it's a near miracle that you got 25 years out of a carbon steel thimble.. you obviously made every effort to prolong it's life.

Greg L.

Gosh, You did well! I'd guess that if someone gt 25 yrs from a stainless thimble they'd be doing well.