Getting liner thru old damper opening

[MeLikeUmFire]

I am going to be running a 6" s/s liner in my masonary fireplace. My damper opening is approx 5 1/2" by maybe 36"(approx). I dont want to destroy any of the damper in case we move and I want to take insert with me. What is the best way to get past damper. Should I ovalize the bottom? I had heard that ovalizing can sometimes lead to increase cresote build-up...Is this true?
If I get it ovalized how do i get it back to round to fit onto the insert??

 

[Wet1]

Ovalize the section at the damper and reshape it back to round after it's through. It's really easy to get it back to round.

 

[DAKSY]

Never heard about ovalizing leading to creosote build-up...
You can squeeze the liner back to round with your hands if you don't
smash it too far in the ovalizing process...
Make SURE you wear leather gloves & it doesn't hurt to wrap the ends with duck tape...
The edges on the liner are sharper than sharp & can leave some nasty gashes if you slip...
One of our guys hadda get 56 stitches to put his forearm back together...

 

[Fsappo]

I agree with the oval then un oval idea and can vouch for the safety tips. I've seen flex pipe tear right thru a pair of work gloves.

 

[ksting]

Ovalize. That's how mine is! Swept it out a few weeks ago after skipping a season and it wasn't bad at all.

 

[Wood Heat Stoves]

time to cut out the damper and remove a section of back plate below smoke shely, or pop out a brick or two

 

[Fsappo]

time to cut out the damper and remove a section of back plate below smoke shely, or pop out a brick or two

I think he didnt want to destroy or alter the fireplace in the event he wanted to sell his home and take the insert with him

 

[Wood Heat Stoves]

^^ then ovalizing liner is his only sloution,
oval liners work fine ime