stove collar, how to fit crimped end stove pipe

The collar on my antique stove is the same diameter as the stove pipe.
The crimped end of the stove pipe is not narrow enough to fit in, neither is the straight end wide enough to fit over the collar.
It looks like the crimped end could be crimped further to narrow it down to where it will fit.
I tried a pair of needle nose pliers and twisting, but the end result does not seem to be improved.

I see there are HVAC sheet metal crimpers with opposing odd and even number of blades, like this one
I also found this dedicated stove pipe crimper, which effectively the same idea as above but is only 2 to 1 opposing blades. I'm guessing the wide single "blade" is to produce a crimp that will make a tighter seal.
Also found this notcher,
Anyone use any of these tools accomplish what I am trying to? which works best?
thanks

I'm thinkin either--- or--- G. I used the 1st pair pictured & it worked well!!

I use what i think is a downspout crimper which does not crimp the length needed for stove pipe. i end up using a very dull concrete chisel to extend the crimp. i put the pipe on a firewood round.

I bought the Masterforce duct crimper from Menards. It says on the back of the packaging:

"Crimps round duct and stove pipe to create a male fitting
Creates a longer, shallower professional grade crimp
for a tighter fitting connection"

It ended up straightening the pipe because it crimps shallower than what the manufacturer of the stove pipe supplies it with
I'm not saying it is a bad tool, I just should have picked up on the back packaging description of "shallower" "tighter".
You can see from the photo, I am holding the crimper as tight as it goes.
I will try something else, maybe I can do something like bambooboy describes.

I use the first one, too.

Tip: Crimp every 3-5 grooves. If you crimp every groove you risk overly tapering the end of the pipe, resulting in a poorer fit.

You can always crimp more, but can't take it back

You can take it back with a hammer and dolly.

What is the OD and ID of the stove flue pipe?

Holdencoal wrote: ↑

Tue. Mar. 03, 2020 8:52 pm

What is the OD and ID of the stove flue pipe?

It is an oval flue outlet on an antique UMCO number 28 pot belly stove, takes a 4 inch flue pipe.
The wide cross section outside measurement is 4-3/4 inches.
The wide cross section inside measurement is just less than 4-5/8 inches.
The short cross section outside measurement is just more 2-3/4 inches.
The short cross section inside measurement is 2-5/8 inches.

The piece of stove pipe I am attempting to fit is the Imperial BM0344 4" x 24" Black Matt Stove Pipe - 28ga
( https://www.imperialgroup.ca/product/stove-firepl ... stove-pipe )

Try this company. I believe they sell through Menards.

http://www.hc-products.com/contact/

They make a nice oval reducer.

Holdencoal wrote: ↑

Thu. Mar. 05, 2020 5:03 pm

Try this company. I believe they sell through Menards.

http://www.hc-products.com/contact/

They make a nice oval reducer.

Thank you for the suggestion. I checked Menards, they only carry the 6 and 8 inch. The manufacturers catalog lists the smallest as 5 inch. The oval collar is not an issue, the pipe I bought is 28 gauge so it was quick to roll it on the carpet a little to get it the correct shape. Now I just need to crimp it enough to fit. I have not spent but maybe 5 minutes trying so far.
I will get it to fit, just was hoping there was a tool to quickly make it fit.

Finally got around to putting forth five more minutes worth of effort and got it fitted in. I spent a total of fifteen minutes probably. This last effort I switched from using needle nose pliers to flat end pliers. The downside is the corrugation at the fitted end has lots of air gaps.

I am going to buy another section of pipe and purchase that notching tool, the third tool pictured in the original post. I am thinking I could get a compression fit that is more air tight.... then again if it is notched might it be spring loaded to pop out? I will find out. The fireplace flue is offset so this pipe at the collar will not have stove pipe above it to weigh it down and hold it in. I am hoping to not have to use cement around the collar.

I bought another two foot section of flue pipe and used the notching tool I bought to cut out pie shaped wedges to get a better fit when inserting the pipe into the stove collar. It gets a better seal than the first pipe that I used the crimping tool and later the needle nose pliers on. In either case there are small gaps all the way around the collar.

For this Umco stove I did two burns outside with the stove in case a previous owner had applied regular paint or some other stuff in hopes to burn it off outside. I have now repainted and applied furnace cement to get a better air seal.

My question is, what would be the best way to plug or seal the gaps in the flue pipe around the collar?

Furnace cement seems like it would be a lot of trouble to clean up around the collar when I swap out stoves.
At one point after I started the first outside burn and came back the temperature at the collar was around 525 F, so I quickly closed the air controls and let it continue to burn with the air leaks in the seams of the stove and it dropped down to low 210s.
My left over fiberglass insulation (pink) says not to use above 250 F.
High temp silicone sealant seems risky at the stove collar, I can see using it around the joints between sections of flue pipe.
I have some rockwool insulation I could use, my understanding is that is made from slag, so it should be high temperature resistant?

Usually the pipe fits over the collar. With modern pipe you might have to flatten the seam on the end to make it fit. Stretch a piece of string around the collar and measure it .If it measures 12.56, four inch pipe should fit. Furnace cement is very brittle when dry and cracks off easily when dry.

Yeah----that won't be very safe G.