Burak Unver

Glenn Herbert wrote:Aside from the rectangular shape not being ideal, looking at the photo reminds me that that stacking method is inherently unstable. At the expense of cutting two bricks a bit shorter and using an extra layer's worth of bricks reoriented at the base, you could rearrange the core to be square and much stronger.
Replace the bottom vertical row of the core with two layers set horizontally, giving a smaller height, and run the heat riser bricks in pinwheel fashion, alternating direction with each course. The bottom course of feed and riser would need a brick cut shorter by the thickness of a brick, so the burn tunnel can be safely bridged. Do that, with the joints clayed up, and I bet it will rocket. You would also need another course of bricks laid flat and pinwheel fashion on the top of the feed, to make up the height lost by the flat layers at the base. This would have the side benefit of giving a wide flat top to the feed surface for more stability (once it is supported by cob enclosing the core.)

Do you have a photo or drawing that you mention above. That would be very helpful.

I made that design because I have that amount of bricks and I didn't want to struggle with cutting the bricks, so I wanted to try if it works.

I didn't apply mud becasu I wanted to see how it works, It didnt work at all.. Should it be a square? Is it a must that edges should be the same size?

My feed tube, burn tunnel and heat riser are all have the same section area, I thought that It's enough to have the same area.

This is how it looks like in real

I tried a rocket mass heater demo with the fire brick I had.

I followed the ratios 1:2:4 | feed tube= 20cm, burn tunnel=40cm , heat riser=80cm

section area is 12x20cm ( equal to 7" system)

when I set the fire it is not burning sideways, flames and smoke all coming out of feed tube. no flow through the heat riser.

where is the problem?

thanks.

My drum is very thick 16mm (3/5 inches) Would it be a problem for emitting heat? Should I choose a thin barrel?

Thank You John, I've noted that..

John Harrison wrote:For insulation, Pumice would be the best choice of the three materials you mention.

Do I need to crush them? Because the grains are like 1/2 or 1 inch size. I was thinking to fill gaps with sand.

Burra Maluca wrote:

You might want to spend some time reading through this thread before you do get it - using metal in the burn tunnel and heat riser

Hi, I read the whole article and totally convinced. But the thing is this, The place I want to build a RMH is a temporary workplace for me. It's a construction site and will last 2-3 years. After that we pack our stuff and settle another place

In the future when I move in to my own house, I'll definetaly build it with bricks..

I'm new to RMH and want to build one before the winter ends, because winters doesn't last long here in Istanbul. So I'm a litte eager to build one soon.

Thanks..

Panagiotis Panagiotou wrote:

Regarding the gap of the manifold i would like to hear it from someone else in the forum.Are you going to use a 6 inch or an 8 inch system?

Actually It depends on the items I scavenge I'll buy fire bricks for feed tube and burn tunnel.

I'm planning to use a steel pipe for the heat riser but didn't get it yet.

I have another question on my mind. What should be the thickness of the insulation layer? I'm asking this because If I make a thin insulation like 1.5 inches and we assume that the heat riser is 8" (8+1.5+1.5=11 inches for the riser and insulation)
The insie of my drum is 27 inches. (27-11)/2=8 inches of gap around the heat riser (B dimension in the first picture I post) 8 inches seems to much to me.. Should I make it even with the insulation layer? Does too thick insulation layer makes a negative effect on the system?

And can I use a mixture of broken glass , sand and pumice for the insulation?

Thanks..

This is the steel pipe I want to use as a drum attached below