How to fit 6 inch diameter stove pipe into 5-7/8 inch damper assembly

[Chris1845]

My apologies as I’m sure that this question has been asked before, but I could not find threads on that topic using the search tool.

We’ve replaced our old wood stove with a “constructed in place” masonry heater. I had a small fan blowing through from the ashpit to the damper at the top of the unit for a couple of weeks to dry out the mortar. I’m now connecting the stove pipe and have run into a problem.

The new stainless steel breech pipe into the chimney is 6” diameter. The ID of the damper assembly visible at the top of the heater is 5-7/8”. My understanding is that may have worked well with double-wall stove pipe, but the breech pipe enters the chimney at an angle, requiring an adjustable elbow. The distance to the nearest combustible surface is greater than 18”, so the solution that I chose was to use single-wall stove pipe (stainless steel rather than black). For this short connection I just need two adjustable 90 degree elbows and a short piece in between. The problem comes from trying to fit a 6” diameter stove pipe into a smaller diameter damper assembly. I’ve “over-crimped” the elbow visible in the photo and I can force it into the damper about one inch (where the green tape is), but the crimps are visible and gives the impression that the fitting is not in far enough. It doesn’t look like a very professional installation.

Is there a better solution to this? I don’t think that I’ll find a stainless steel adapter like this one that I mocked up in the photo below.

Thank you for any insight.

Chris

 

[begreen]

Look for an appliance adapter that is slightly small than 6" on the stove side. Duravent Durablack makes one, but there are others.

 

[Sailrmike]

Knowing that masonry heaters extract so much heat from the exhaust gases, i would be hesitant to go with single wall. You do have a short run there, so maybe single wall is ok. I've been extremely happy with my I.C.C. Ultrablack doulbe wall, been using it for 3 years. The Jotul flue collars are a little funky, but the Ultrablack appliance adapter works beautifully to make the connection. Worth considering for your application

 

[Chris1845]

Knowing that masonry heaters extract so much heat from the exhaust gases, i would be hesitant to go with single wall. You do have a short run there, so maybe single wall is ok. I've been extremely happy with my I.C.C. Ultrablack doulbe wall, been using it for 3 years. The Jotul flue collars are a little funky, but the Ultrablack appliance adapter works beautifully to make the connection. Worth considering for your application

Thanks for the response. Although I have not seen one, it is my understanding that 90 degree elbows for double-wall stove pipe are not adjustable, so I cannot accommodate the angled entry of the breech pipe into the chimney. Is that true?

 

[Sailrmike]

Thanks for the response. Although I have not seen one, it is my understanding that 90 degree elbows for double-wall stove pipe are not adjustable, so I cannot accommodate the angled entry of the breech pipe into the chimney. Is that true?

Correct, 90° double wall stovepipe is not adjustable. However, if you used (2) 45° elbows instead, you will get some adjustability. @bholler and @begreen do you think that would work?

 

[bholler]

I can't think of sn adjustable double wall elbow

 

[mjons92]

I would recommend to first convert inches into CM: Metric conversion from inches (amazingconverter.com) - then try to find adapter from Europe, centimeters are more precise. 6inches equals 15,24cm so you need to look up for 15.5cm adapter.

 

[MongoMongoson]

This is a very similar problem to what people have with their old Fisher stoves with top exits. If you are overcrimping the pipe, you want to pull the crimper towards the outside of the pipe while you are doing it. That will help straighten the crimp and give you less of a cone on the end of it. You aren't going to be able to eliminate the sight of the crimp completely, but you will be able to make it look a little neater. Y

As begreen mentioned, they do make stove pipe parts to account for this. I have seen them mentioned in the Fisher forum on this site a number of times.

I think this is the specific part begreen was talking about. The crimped end should measure 5 5/8".

6" DuraBlack Double-Skirted Stovetop Adapter - 6DBK-ADDB

6'' DuraBlack Double-Skirted Stovetop Adapter - 1672 - 6'' DuraBlack DS Stovetop Adapter- Find 6 inch single wall DuraBlack adapters here along with expert advice and installation information - NorthlineExpress.com

www.northlineexpress.com

That should solve your problem, but it will be black.

 

[MongoMongoson]

Found the dimensions...



And I also found this, which is stainless. It says it measures 5 15/16, so you'd need to crimp it another 1/16" but that should be doable.


Edit: I just realized that I have been replying to a thread from Oct of 2020. That's fun!