8" chimney thimble 6" coal stove - what do I do

8 (maybe 8.125") hole in wall like thimble. 6" coal stove pipe. CO filled house twice in past 2 years so I am installing this air tight and not the stupid adapter I've been using. Advice on how to get thimble to take 6" pipe would be much appreciated!

I just stuff fiberglass insulation around mine at the thimble. No problems..

Or get a 6” to 8” transition smoke pipe fitting

Clay thimble...
Rockwool backer...
The rockwool will not burn or absorb water...
Prevents the stove cement from disappearing into a void...
Centering the 6" stove pipe...
Pack with stove cement...

https://www.rutland.com/product-category/rutland- ... 16fd43adaa
is black...

https://www.rutland.com/product/stovo-stove-morta ... 16fd43adaa
is the best...
grey but paintable after cure...

https://www.amazon.com/Door-Gasket-Stove-Pellet-B ... B07664CW49

https://www.amazon.com/Door-Gasket-Stove-Pellet-B ... B0766512WP

I linked to 1 1/4 and 1 1/2 inch rope, links not working for me but you can find it on Amazon..

I have 7" into 8" thimble using 1" rope..

Now there ya go...
And slides out easy for cleaning too...

CapeCoaler wrote: ↑

Tue. Nov. 12, 2019 9:37 pm

Now there ya go...
And slides out easy for cleaning too...

Not really, it's tight, very tight and a pain to do but it works great. It allows for thermal expansion , and a disconnect from the thimble.

You attach the rope to the end of the pipe, drill two holes about an inch apart and use some wire to attach the rope, put it in the thimble, then wrap the rope one turn and pound it in with a 1x1 wood stick and a hammer, then wrap the rope around again and pound it in, repeat over and over until its all in , at least a foot worth.

To remove just pull the rope out one turn at a time. The rope is expensive but it will last, been using mine 15 years so far.. and pull it apart every year..

ETA, just remembered, I use one of those BIG paint stirring sticks, works good.. you can get them at Home Depot.

8" chimney adapter (thimble), 8" to 6" reducer, done.

coaledsweat wrote: ↑

Tue. Nov. 12, 2019 10:01 pm

8" chimney adapter (thimble), 8" to 6" reducer, done.

Simple and easy. Every hardware store has them.

Ahem...

CO filled house twice in past 2 years so I am installing this air tight and not the stupid adapter I've been using.

CapeCoaler wrote: ↑

Wed. Nov. 13, 2019 1:23 am

Ahem...

Adapters are not stupid but an installation can be. I used a 6 to 8 adapter for years without a problem. I seal at the thimble with high temperature caulk. Terra cotta thimbles are often not perfectly round and may have gaps when using a round pipe. I think there was more to this story of the house filled with CO besides the adapter.
https://www.lowes.com/pd/3M-Fire-Block-10-1-oz-Gr ... lsrc=aw.ds

Weak chimney. A strong chimney would get by fine without the rope if the fit is tight.

grumpy wrote: ↑

Tue. Nov. 12, 2019 9:35 pm

I linked to 1 1/4 and 1 1/2 inch rope, links not working for me but you can find it on Amazon..

I have 7" into 8" thimble using 1" rope..

Ive never seen that before but thats a snug fit! You might be able to save money on the rope on ebay or amazon.

I agree with Scalabro, weak chimney draw. Might have to make it taller or take other measures, plus a good fit.