Cindy Mathieu wrote:
cindy, on your video of assembling the vermiculite riser i noticed the inside seemed to be a different colour to the outside. do you use anything like iITC100 or satanite. on the inside of the riser?
Good eye, Bob
I am not familiar with ITC 100 or satanite.
Yes, the inside has a heat reflective coating which is supposed to increase the temperature of the exhaust and extend the life of the material. It's very expensive and we never did the side by side tests it would take to confirm that it did any good in our application.
Cindy Mathieu wrote:
Also in consideration, Dragon Heaters cast their rocket cores in a single piece.
Dragon Heaters casts cores in a left and right piece and ties them together with the paper gasket in between using stainless steel banding, as you recommended to Thomas Rubino.
In the image, you can see the stainless steel banding in 2 places on each size (4" 6" & 8"). The heat riser is made from vermiculite board and there is a paper gasket under it as the interface to the burn tunnel. There is also a paper gasket between the feed tube (which has a P-channel in it) and the burn tunnel.
The burn tunnel design is as Peter van den Berg discusses on page 111 of the 3rd edition of Rocket Mass Heaters. We have licensed his design for commercial production in the U.S.[/quote
cindy, on your video of assembling the vermiculite riser i noticed the inside seemed to be a different colour to the outside. do you use anything like iITC100 or satanite. on the inside of the riser? i am planning on making a riser from vermiculite after i finish experimenting on the outside test RMH. seems like together with the cast core it will save quite a bit of weight, not counting the thermal mass of course. the plan is experiment ion the bus before installing it in the yurt with the thermal mass.
thomas rubino wrote:Hi Bob; when i built my 8" core using matts plan's, I had 2, 50 # bags of fireclay on hand and I didn't have quite enough! I needed 3 bags ! Even on a 6" I would have no less than 2 bags. I'm sure that rockwool will work fine as a binder. Plywood will work as well as hardy board or aquaboard, what ever you use will burn out quickly. Also matt has plans for a cast riser with the same ingredients , You will need a bag of fireclay for this also . Matt used a piece of stove pipe for his sacrificial inner form , I used a piece of (soni tube) cardboard concrete form as my inner form and it worked great! Good luck Tom
Mikael Long wrote:Hi Den
I did something like that. While the drum that sits on top of the stack was heating up I put mud/clay on it. Even with it steaming I could get it to stick but it was not easy and talk about water vapor release. At one point it was a tropical rain forest in the small space I was working. It was about 50F outside so not freezing but still cold to be working with wet clay. Starting and keeping a fire in a wet RMH is hard and requires constant attention and may not run if its too cold. Use a torch or heat gun to get it going first. I also did multiple coats on the whole RMH which took about two weeks start to finish I could run it in between to stay warm it just looked well unfinished. I looks nice now minus some small cracks which I will fix next fall or this spring. I probably will redo the whole thing and go for a larger unit. This was my first attempt and I want to pull it apart and make change to get even more from less.
trying to post youtube link not sure if that is right but it is a video of my unit in action.
hi, i am a newby so may / does not know what i am talking about yet, so please forgive me if i have this wrong. from what i have read the outer barrel acts as a cold area for the hot gases to descend into as they leave the riser. this needs the outer barrel to be relatively cool i thought for this process to work properly. covering the barrel with clay will hinder this process somewhat i would have thought.