Is there a sleeve, or something, to pass 6" pipe through 8" clay thimble?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Jan 29, 2021
147
VA, east central
I have a masonry chimney w/ clay 8" thimble and am putting a Harman p68 in to take over the job of a Buck Model 81. Initially I'm just running the vent into the chimney. I bought a 6" x 12" section of SS durablack pipe to go through the thimble. I'll be connecting my 3" durablack PVP pipe to this using the M&G DuraVent 3PVP-X6 adapter for the time being. In the next month or two, I'll be running a 6" SS liner down the chimney. I want a 6" liner because my effective vent length is too long if I used a 4" liner AND I want to be able to swap the buck stove back in if ever needed, I'm not getting rid of that.

I've looked for a sleeve or similar product to allow a tight seal between the 6" pipe and the thimble but haven't found anything. What is the acceptable way of filling that space? Is there a high temp insulation that I can pack into it and maybe use trim rings on the back and front within the thimble to support the pipe?
 

begreen

Mooderator
Staff member
Nov 18, 2005
90,572
South Puget Sound, WA
Try 1" stove rope gasket.
 
Jan 29, 2021
147
VA, east central
Try 1" stove rope gasket.
Thanks, that was gonna be my last ditch effort if I couldn't find anything else. I wanted to make sure I wasn't missing anything that might have been preferred.
This whole process of looking for venting etc. to move to a pellet stove with existing masonry chimney has been frustrating. I decided on Duravent pellet vent pro, but they don't make it obvious as to what to use to transition properly from 3" PVP to a 6" liner. They have an adapter that seems like it might be intended to transition to a liner tee. Looks like it should work, I'll just need high temp silicone to ensure a tight connection.