DIY isulated stove pipe?

are there any videos/htreads/pics of homemade doulble walled isulated pipes? im not talking about for going through walls and stuff. just the outdoor sections, so gasses can stay hot all the way up for draft. would 8" around 6" packed full of something work for this purpose?

Someone posted about doing exactly this just recently. I don't remember which thread it was in though...

Ron Bush : Yes it can be done, it requires careful measuring and bracing

A tip that most wood stove operators learn by doing wrong the 1st time (you have a 50/50 chance of doing it right). The crimped end of the stovepipe
should always point downward and back toward the stove /heater

With a conventional wood stove this prevents creosote and other combustion products from running down the inside of the pipe and leaking out a joint
to Flow down the outside of the pipe, basically it looks like hell and amateurish.

With the Rocket Mass heater any water vapor that can condense will an if it can leak out at a joint it will wetting the insulation a distorting its R-Value

The pipe should be screwed together in three places (short stubby screws) and all joints sealed with tape

Please use help and be cautious working on ladders off of the ground For the good of the crafts Big AL

Pearlite or vermiculite work. Only one inch gap is not much, better to upsize the outer pipe at least two sizes. The right length of screws in the outer pipe will help keep it centered, but the need to have some space and no point so they don't work a hole in the inner pipe as it expands and contracts.

I think the outer pipe in such an assembly should be installed with the crimp ends up, so rain will not have a way to get in and any moisture that does get in will be able to drain out. (There will be no nasty gases to make stains in this location.)

The post that I saw, if you can't find the original, did say that for rockwool insulation you need to assemble and pack it in place section by section, no preassembling sections on the ground or trying to pack more than one length at a time.