I just finished construction of a 400 sq/ft cold frame in the back yard. I figured it didn't need to be heated. I got sad that there was nothing left to construct. Then I found this site, and got exited over rocket mass vids. Then I remembered some old stove looking thing and drum and in my shed. Now i'm wondering just what to create.

I'm still trying to read up. I can't help my amateur enthusiasm.

- Does anyone know what the Hercules metal stove might be? It's Sears Roebuck placard is beyond google's knowledge. There is a max psi etching on it and some openings at the top, so maybe a boiler? Interested in best exploring how this can be used as the fuel side of a rocket mass system.
- Do you think I could safely heat or boil water?
- Is there a danger in using the old drum? I don't see any rust on it, but have no idea what it was used for in it's previous life. Possibly oil.

Barney Tighe : With any Solid fuel fed system the owner operator takes on several additional layers of responsibility! By the very nature of our rocket mass heaters operations
you are the only regulator of just how much wood fuel gets fed into your system, and there are no fail safes for you to fall back on -if you over fire your D.I.Y. built system !

Our Fellow members from the British Isles tell us that all forms of solid fuel PRESSURIZED water heaters are banned for use in Residential homes, I am told that as common
practice when the pipes start banging in the middle of the night, the head of the house gets up and draws off a bathtub full of hot water to equalize the system and pops back into
bed !

The Myth Busters made up an entire episode on what can happen to your lowly hot water heater if the safeties fall ! If you have not seen it you should look for it on U-tube ! Here at
Permies it is simply called Boom-Squish! Think the Boston Marathon Bombing with more full thickness/full body burns !

As always, after you have posted an original comment, our computer will try to find 'key words'' and phrases and will post a listing of '' Similar Threads'' at the bottom of that pages
forum topics - Nothing that might be said there will change my answer ! Big AL !

Barney; Don't mess with the old boiler , round up some firebrick and start playing with rocket stoves! Before you know it you will be building a heated greenhouse!

Thanks for the advice tom, after reading more the hercules is just an extra part. I may sit it overtop the inlet for show. Your picture of your setup is what I believe i'm going for now.

Re: my 55 gal drum. There was still some oil in it, which I have now drained out. Can i expect that residue will burn out? Should i look for a new drum?

Barney:First thing is you need to get a copy of ianto evans book rocket stoves you can snuggle up to .This book is chock full of information and after reading it you will be better able to converse with other like minded people and know what each other are talking about! That said, The best 55 gal drums to use have a removable top, this allows you access to your heat riser as well as a way to clean any ash buildup. What ever drum you use, all paint and internal residue HAVE ! to be burned off For me the easiest way is to turn open end up and use it like a burn barrel, fill with dry wood waste and let it rip. There are many other ways to burn them off but for me this was the fastest. Order a copy of ianto's book, locate some firebrick you can salvage, round up some stove pipe and start playing in your back yard. These stoves are so cool that you will have to have one ! Tom

rocket stoves you can snuggle up to will make a great stocking stuffer.

after cutting off the lid, the oil residue looks pretty unmanageable. I will start looking for a drum w/ removable lid.

Barney Tighe : T.R. is giving you good advice, goto> rocketstoves.com to download your PDF Copy of Evans' Great book
'Rocket Mass Heaters'with ~100,000~ HMHs made world wide, most follow 'The Book' and 95% of all the 1st time Builds
(That Worked ) closely follow 'The Book', any other questions can be solved here at Permies.com (or our sister site richsoil.com)
For the good of the craft! Big AL!

Thanks for all the help. I've followed most of your advice thus far. got a new book, barrel, and pile of bricks. I've tried two crude test burns in the back yard. Both of which i'd consider promising and a learning experience, but not a success. The biggest issue i'm seeing is that the fire wants to crawl up the wood in the intake and back-smoke.



This is a picture of the most recent burn. There is a brick chimney hidden in the barrel that goes up to about 2" short of the top. After blowing in the inlet I would get what appeared to be a correct rocketing effect, but a few breezes later the smoke would start billowing out the feed tube.

Issues with test setup:
- Not very air tight. Dry stack of bricks
- only 1 segment of exhaust
- wind over intake

Issues that may be in the design:
- The chimney does not have an insulating wide stack (have not come across a good mat)
- Shortness of burn tunnel (i shortened by 1 brick length this go around)
- cross-width size of burn tunnel / chimney

Do you recommend pushing forward and trying to emplace inside of the greenhouse? Hoping the longer tunnel, wind shielding and morter-air tightness will make the burn more effective. Or should I continue to do outdoor burns until I get a shape that works?

I would recommend:

1. Don't move it inside until you have solved the "smoking out the feed tube" problem.

2. Try a 90° elbow and get your exhaust going vertical. If that solves the "smoking out the feed tube" problem, you know that you have to do something different as far as your cob is concerned.

In general, exhaust doesn't like to go down; it likes to go up.