Two-piece trim collar to go over the thimble on an installed stove?

[somerswi]

Our wood stove was installed without a trim collar over the mortar at the thimble, which is just above and behind the stove itself. I would prefer not to pull the exhaust pipe either out of the stove or the thimble in order to put a one-piece trim collar over the mortar. Does anyone know of a two-piece trim collar that would go over the installed exhaust pipe at the thimble, and then snap or screw together?

 

[DougA]

ICC makes one that fits over a cathedral ceiling kit. Not sure if it might fit but here is the link:
http://www.icc-rsf.com/main.php?t=chem_produits&i=6&d=&l=en

Not sure if they are sold separately. You could buy the oval one & cut it in half, otherwise I would think any place that makes ductwork can do it.

 

[Ford850]

Another way would be to detach the horizontal pipe from the upright (or elbow, depending on your layout). You only need a 1/4" gap to slip the ring between the fitting and onto the horizontal pipe. That way you can leave it in the thimble, and also leave the vertical pipe in the stove.