Duratech chimney exterior feels hotter than it should... Design Styles, Chimneys and Finish Discuss Duratech chimney exterior feels hotter than it should... in the Pizza Oven Design and Installation forums; Thanks, all, for your suggestions. My current thinking is that I'll line the inside of the chimney with a single-walled, ...

[sjmeff]

Thanks, all, for your suggestions.

My current thinking is that I'll line the inside of the chimney with a single-walled, 7" stainless steel chimney liner that's wrapped in 1/2 inch of insulating blanket (I have some left over). The inner dimension of the chimney would be 7" rather than 8", so hopefully it would still be sufficiently large to draw for my 42" dome (and not make the front arch black from smoke).

The alternative is to insulate the outside of the chimney, but I think I'd have a tough time making it look right. I'm also not keen on the idea of stuccoing up the chimney.

If I were to do it all again, I'd probably build a brick chimney, but switching to that now would require too many modifications to what I've already built.

Fingers crossed.

S

[sjmeff]

One other question regarding a lining inside my current 8" chimney. Does anyone have an opinion as to whether my proposed 7" lining should only go up, say, 12" rather than the full 36"?

The possible advantage to having it only go part-way up would be that the top part of the chimney would be a full 8" and might draw better.

The downside could be that the whole chimney still expands/contracts and causes the stucco to crack over time (even if it's not hot where the chimney and stucco meet).

I hope I'm explaining this well.

S

[ThisOldGarageNJ]

Hey Stephen,,
Im not sure if it would matter, going 7-8, But I would just keep it the same to avoid another strange variable....

Mark

[mikes334]

So did you find a solution? I know when I had a duratech issue I call the guys over at Chimney Liner Depot with my duratech chimney. They helped me out a lot.

[dpike]

BTW, laser thermometers don't actually use the laser to detect the temperature, the laser is just for centering the infrared detector.

[sjmeff]

So did you find a solution?

I found another thread that discussed leaving space between the stucco and the Duratech chimney and then filling the space with waterproof, high temp silicone sealant. That seems a lot easier than trying to add another chimney within my existing one.

BTW, laser thermometers don't actually use the laser to detect the temperature, the laser is just for centering the infrared detector.

Ah, good to know. Thanks!

[nissanneill]

s
I feel that your 7" chimney will not cater for your 42" oven. I think that you will find that especially if you don't have a fairly large entry to the flue collecting and funneling the smoke up into the flue, that it will come out the front and blacken your front arch.
I would most certainly run the full length because as it heats up, it will draw better and literally suck the smoke that way.
I have an 8" flue that is 10' long (3 sections) and no smoke escapes through the front arch at all.

Cheers.

Neill