We tested our initial rocket stove design today, and it works great. It’s still out there burning away. The burn is really clean, which is great. In the picture, the bottom (insulated) stove pipe isn’t part of our planned setup, it’s just there to assist the draw.
For this stove I’m using two different sizes of fire brick. The light colored bricks are the salvaged bricks I got for 50 cents apiece. The buff are new (larger) bricks I picked up at our local redi-mix plant for $1.50 each. Between the two I can configure the layout to give me a good 6″ burn tube. I probably have enough brick to build a riser, but I’ll get better draw with a round riser tube.
I still have to get perlite, mortar and something to use for the grate. I’m using light stainless screen in the test setup for the barrier between the cleanout/ash chamber and the feed tube, but that will hold up for only a short time so there’s no point in using it. I’d love to find some heavy 316 stainless stainless screen as that will keep the embers in the burn area and allow the ashes to drop through. 316 stainless will hold up for about 4000 burn hours. Steel will last less than 1/4 of that time for the same material weight, so the expense of stainless is warranted. Finding stainless screen in the configuration I need may not be that simple, so I’m planning to use something else. Hibachi grills are fairly common. I’d have to replace it every year, but it’s affordable and available. We’ll see what I can find.
Terry and I were discussing the ash clean out access under the feed tube. I’d like to use 6″ square pipe with a cap. I don’t have a lot of room under the stove for ash clean out, so I may see about making a 6″x2″ slot with a tray. We’ll see what we come up with. This isn’t the only ash clean out we need, but it is the most critical.