To all experts in woodburning:
I have a problem I'm hoping you can help me solve.
First, some background:
I grew up burning wood and have had a stove in my existing home now for several years. I've recently torn out the old chimney (poorly constructed) and replaced it with a new, two-flue, clay-lined block chimney. I'm ready to hook up my two woodstoves, 1 per flue, in the basement and on the first floor. Both installations are directly into the block chimney with no walls/flammables through which the stove pipe must pass (I will be simply finishing the block to match each room). I had the mason install an 8" clay thimble to accomodate the 8" stove pipe required for each of my wood stoves.
To my surprise, however, the thimbles both have inside diameters of 8 1/2" (outside of approx. 10"), and I'm not sure how to proceed. Any previous stove hookup in my experience involved an iron or clay thimble that would accept the appropriate stove pipe (6,7, or 8" dia.) for a snug press fit. But these thimbles leave a considerable gap around any standard 8" stovepipe.
I've heard that clay thimbles and liners have somewhat variable tolerances, but I've not encountered any before that were this oversize. To make matters more confusing, I've gone on several manufacturers web sites, and some list their eight inch thimbles as 8" i.d., others as 8 1/2" i.d. Perhaps the difference is that some manufacturers list actual i.d., others nominal? At any rate, my mason seems puzzled by the oversize as well, but I told him I wanted to check around first before he attempted a fix. Some people seem to advocate a permanent cemented connection, others some kind of packing with fireproof insulation. Neither strikes me as ideal, and I can't believe I'm the first one to run into something like this.
So my two part question is this:
1. Why are the thimbles oversized?
2. How does one hook a stove to them in a safe manner that also permits easy uncoupling for cleaning?*
* i.e. I want to be able to disconnect the stovepipe for annual cleaning without having to chisel away refractory cement. I also dislike the idea of packing insulation between the stovepipe and thimble--I prefer a solid, "hard" connection. Is there some kind of metal adaptor that I can use to reduce the interior diameters of the thimbles so that standard 8" stovepipe will make a snug press fit? Or will I have to have something fabricated?
I've not run into this situation before, and I'm not having any luck finding answers from suppliers, so I'm hoping I can get some answers here.
Hoping you can shed some light on this situation,
Timberscribe
western Virginia
I have a problem I'm hoping you can help me solve.
First, some background:
I grew up burning wood and have had a stove in my existing home now for several years. I've recently torn out the old chimney (poorly constructed) and replaced it with a new, two-flue, clay-lined block chimney. I'm ready to hook up my two woodstoves, 1 per flue, in the basement and on the first floor. Both installations are directly into the block chimney with no walls/flammables through which the stove pipe must pass (I will be simply finishing the block to match each room). I had the mason install an 8" clay thimble to accomodate the 8" stove pipe required for each of my wood stoves.
To my surprise, however, the thimbles both have inside diameters of 8 1/2" (outside of approx. 10"), and I'm not sure how to proceed. Any previous stove hookup in my experience involved an iron or clay thimble that would accept the appropriate stove pipe (6,7, or 8" dia.) for a snug press fit. But these thimbles leave a considerable gap around any standard 8" stovepipe.
I've heard that clay thimbles and liners have somewhat variable tolerances, but I've not encountered any before that were this oversize. To make matters more confusing, I've gone on several manufacturers web sites, and some list their eight inch thimbles as 8" i.d., others as 8 1/2" i.d. Perhaps the difference is that some manufacturers list actual i.d., others nominal? At any rate, my mason seems puzzled by the oversize as well, but I told him I wanted to check around first before he attempted a fix. Some people seem to advocate a permanent cemented connection, others some kind of packing with fireproof insulation. Neither strikes me as ideal, and I can't believe I'm the first one to run into something like this.
So my two part question is this:
1. Why are the thimbles oversized?
2. How does one hook a stove to them in a safe manner that also permits easy uncoupling for cleaning?*
* i.e. I want to be able to disconnect the stovepipe for annual cleaning without having to chisel away refractory cement. I also dislike the idea of packing insulation between the stovepipe and thimble--I prefer a solid, "hard" connection. Is there some kind of metal adaptor that I can use to reduce the interior diameters of the thimbles so that standard 8" stovepipe will make a snug press fit? Or will I have to have something fabricated?
I've not run into this situation before, and I'm not having any luck finding answers from suppliers, so I'm hoping I can get some answers here.
Hoping you can shed some light on this situation,
Timberscribe
western Virginia
