Jeff Rutkowski

HELLO. Yes, I have not checked in for a while.  My rocket mass heater was wildly successful.   you can check it out here :

https://youtu.be/YYAJu-WyT24

I had to take the rocket mass heater apart and remove it from my workshop because I could not afford the space which it was occupying.  I am in the process of having a Froling S3 turbo wood gasification boiler installed  with an integrated solar hot water system and approximately 1100 gallons of thermal storage.  

Rats. I tried the links but they are both for organ donors in Norway.

So I have fired up my antique backhoe and found some clay which passed the finger test. I dried some, pulverized it, and mixed it with sand to make some cob to seal the unit up. The trouble is that the clay is nearly as hard as stone and can't be mixed up using one's feet and a tarp. Now I am looking for powdered clay- any type I think will work. I am looking for a source now. I would like to make a cob that can be re-used over and over. Cob in the heat exchanger is now out of the question because of the constraints of time and money. I'll be using it on the outside of the rocket stove part- sealing the barrel and burn tube and coating the outside with it.

Thanks for the timely and helpful info! You are correct about the design- J-tube, heat riser ending 2" from the top of the barrel, and loading sticks vertically. I especially appreciate your volume to surface area discussion, after spending 10 winters in Alaska- although a few of those were in the Tongass where it is much warmer than the ADKS in the winter. I was not too clear on what I'm doing with the blocks. I am going to run the 6" pipe along the floor between two rows of block and fill the spaces up with sand, elbow up at the end of the run and run a "second layer" of pipe, block, and sand back toward the barrel and then put the chimney up just before I get back to the barrel. I may not use the sand but use cob instead as you have suggested. That sand has got to have a lot of air in it.
Time is of the essence now that I am in the middle of cider season, putting a new sugarhouse in, bottling honey, tending to about 300 raspberry bushes, and slowly getting the firewood into the shed. You know the drill, being an upstater yourself. I would like to be able to get it all apart in the spring- the cob I could re-use next season if I have time to make it this year. I think I will get that PDF you spoke of. The idea being to have enough time for one more sailboat outing and one more cruise on the 33 year old motorcycle up through the park and back- I am in the southern part. Thanks again.....J

Building a rocket mass heater in my shop for this coming Adirondack winter. I am using 6" pipe and flues and was wondering if anyone has an idea that a 30 gallon barrel would work ok for this. I have built 3 different prototypes outside and fired them up using no mass but just a straight 6" stove pipe connecting at the bottom of the barrel. I have the burn tube (6" metalbestos 3 feet long) 2 inches from the top of the inside of the barrel.
The latest version seems to work well, the only thing is that the coals seem to build up in the horizontal part of the fire chamber and slow the draft. Maybe just putting too much wood in, plus the prototype does not have the draft that the finished one will have. I plan to run the flue pipes between cement blocks and cover them with sand- maybe a total of 20 feet. Need to be able to dismantle it in the spring because of limited space. Looking for any comments/suggestions. Thanks. Jeff