Pipe wont fit Grandpa Bear

[Ironbull]

Hi folks, new guy here and new to to wood stoves. Lurked here for a few weeks but now I have a problem and could use some guidance.

I have recently purchased a Fisher Grandpa Bear stove but can't seem to get the pipe to fit the flue. I have searched here and it has been recommended to get some crimpers and over crimp the pipe, so I bought myself some and tried that without much success. Maybe my cheap crimpers don't crimp enough? Anymore suggestions? Perhaps there is an adapter out there I'm not aware of. I don't want to keep throwing money at it without results.

 

[Todd67]

Welcome to the forum!

I had the same problem when I installed my Mama Bear. My stovepipe crimpers from Lowe's didn't quite get the pipe crimped enough. Maybe I wasn't doing something right, because it was my first (and only) woodstove installation project. There might be some good videos on YouTube now that show how to crimp a stovepipe properly, but I don't remember finding any in 2012.

I made a collar that would fit over my flue, then slid the stovepipe elbow inside the collar. I sealed all of it with Rutland cement and I've had no issues at all.

Here is a pic of my collar & elbow connection


Here is the link to my Mama Bear Restoration & installation project, where you can find more details than what I shared above;

https://www.hearth.com/talk/threads/mama-bear-restoration-and-installation-project.91558/

 

[coaly]

Does your stove have a top or rear outlet?

 

[Ironbull]

It is a 8" rear outlet. I have found what's called a stovetop adapter that is made by imperial for a flue that is smaller than the pipe. I ordered that, so we'll see what happens.

 

[coaly]

That will work, or you could have used the side of a Tee over the outlet pipe and capped the bottom. You have 8 inch OD instead of 8 inch ID.

 

[Ironbull]

Well I would rather have a tee for an easier clean out. So I may go that route instead.

 

[78CJ]

That will work, or you could have used the side of a Tee over the outlet pipe and capped the bottom. You have 8 inch OD instead of 8 inch ID.

I looked last week at a tee and this is what I think will work, I have the same thing.

 

[coaly]

If you have an elbow, you can try the female side to see how it fits over the outlet pipe. That pipe is normally 8 inch OD. You can't use the elbow backwards like that since condensate can leak out onto the floor behind stove. Use of the Tee allows any water vapor that condenses in pipe to drip down into the cap to be evaporated. Back when all stoves had O.D. dimension pipe, it was common to over-crimp any male going into the stove. It was more difficult with an elbow on the back than a straight pipe. Later, pipe was made for stove outlets with the Inside dimension being 6 and 8 inches to fit stove pipe.
The thinner the wall, the larger the inside opening, but there are cases where a fabricator bought thick wall pipe up to 1/4 inch, so the inside diameter can be as small as 5 1/2 for 6 inch and 7 1/2 for 8 inch. That is probably what you have. Crimping pipe to fit that takes some practice. You crimp around and around making it smaller and smaller, AND bend outward to keep the reduced end straight, instead of getting too funnel shaped.

You will use crimpers anywhere you cut pipe to a shorter length, so you will use them and get better at it.

 

[Ironbull]

My OD is 7 15/16 and my ID is 7 9/16. I have an old elbow that came with the stove that the Male end fits with some force. It has an entirely different style crimp than my new stuff. The crimp on the old is slanted or spiraled with more crimps per inch than the new. I'm going today to get a tee and see how that works out. Will let ya'll know when I get it. Thanks for all the suggestions.

 

[Enplater]

I got a tip that you need an 1872 double skirted stove pipe adapter. See pictures. I bought one and a new 8” elbow fits right in. See pictures.