Big thimble.

[Archminer]

Wasn't sure where to ask this since it's just a thimble question but here goes. I have a wood/coal furnace that has a 6" pipe coming off of it. I have a 40-45 foot masonary chimney with an 11 inch thimble. I cant seem to find a adaptor to go from 11 to 6 or even 8. I made one myself last year from some old 11" pipe that was left over from the big coal furnace that used to be there. But was wanting something a little better. Any suggestions on where to find an adaptor or what to do? Or should I just make another one? Lol.

 

[bholler]

what size is the flue? i would think with an 11"crock your flue is going to be massively over sized for a 6" vent stove

 

[Archminer]

13" masonary flue. It's in great shape. Real good draft. Just need to resize the thimble.

 

[bholler]

I think you would benefit greatly by a properly sized liner. What stove is it? I guarantee it will preform much better with a properly sized liner.

 

[mellow]

Rockford can make a custom size reducer, but as mentioned you would be better off with a liner, even if you have to add a damper due to the height.

(broken link removed to http://www.rockfordchimneysupply.com/custom_shop.php)

 

[bholler]

Or you could also put a smaller masonry crock inside the large one and pack with fireproof insulation and then mortar it in. But you will not regret doing a proper sized liner. Also have you had the chimney inspected with a camera to check the condition?

 

[Archminer]

Or you could also put a smaller masonry crock inside the large one and pack with fireproof insulation and then mortar it in. But you will not regret doing a proper sized liner. Also have you had the chimney inspected with a camera to check the condition?

Yes on the inspection. They told its one of the nicer chimneys the have seen. Awsome draft. Plus they said that the bigger chimney helps when the coal soot starts to stack up in it. They told me that some people have problems with that with newer chimneys cause there smaller.

Can't remember the name, but it's the small sized coal furnace from TSC. I burned all last year with it. Figured out I needed a baro and manual damper to control it. (With coal or wood). After figuring that out I get nice, controlled, long burns. Really hate to try and change it. Geuss I'm going with, if it ain't broke, don't fix it.

 

[bholler]

Was that a certified sweep that said the bigger chimneys help? If so he should loose his certification because he is dead wrong i am sorry. And you should never have a manual damper on a coal unit just control it with the intake and baro. And if you burn wood there should be no barometric damper. Is it a furnace or a stove? And where is the manual damper positioned in the pipe?

 

[Archminer]

Yes, there certified. It is a furnace. The manual damper is located in the upright pipe from the stove. The baro is just before it goes in the thimble.

I live on a hilltop with lots of wind. It's very ify to control any stove on this hill. Even with my small stove on our enclosed front porch(much shorter, smaller chimney). When the wind kicks up it either boom or bust. Burns like hell or it just won't burn.

Btw, most, If not all people around here have a Manuel damper on there coal furnaces and stoves. In fact, I don't think I've seen one without a manual damper. Why do you say never to use one?

 

[bholler]

Because if it is shut down a little to hard co will back up into the house. That is why coal furnaces never have a damper restricting the exhaust. Your baro damper should be able to control the over draft from the wind if it is adjusted correctly and if it is not enough you can always add a second baro damper. It will also control the over draft more if the liner was sized correctly.