Like the title says, I'm a new member, but I have been creeping the site for a while. Lots of info here. Great site. Seems everyone is quite eager to help each other out. I'm in eastern Ontario, Canada if anybody was wondering. I can see New York State from my front porch.
So... I do have a couple of questions. 1. When using firebrick in your build can it be 1 1/4 thick ones or should it be the 2 1/2 thick ones. I ask this because there was a recent post on kijiji in my area for a skid of the 1 1/4 x 4 1/2 x 9. The person is selling at what I think is a good price.
2. I have half a dozen sections of used insulated chimney, the stainless type (Selkirk). Can these be used as a riser in the build inside the barrel or will then burn up too quickly?
The firebrick splits are a fine material for most of the combustion core, if you can get them at a good price. Where I am they generally cost the same as full size firebrick. Lay them up on edge for sidewalls and heat riser, with insulating backup. Make the backup rigid around the feed tube and burn tunnel, as those areas may see considerable knocking over the life of the heater. Around the riser, you can do something as simple as rockwool batts wrapped and tied with wire or wire mesh.
For the burn tunnel roof you may want to use full size firebrick, or at least lay the splits on edge for strength. That roof gets tremendous heat stress and needs all the strength it can get.
The insulated stovepipe you have could be an excellent resource for your chimney as it goes through the roof and at least two or three feet above it, if you don't already have a masonry chimney to connect to. It will not last as a heat riser.
Thanks for the replays and the info. The chimney sections are left over from the wood stove install I did this past summer in my wood shop. I am finding that the stove is having a hard time heating my shop, only about 16x32, and it cools down real quick. So my thoughts are to do a RMH in the corner where my little wood stove currently lives.