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Rocket forge, is it doable?  RSS feed

 
Chadwick Holmes
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So, I heard Paul mention a blacksmith mention that you could heat steel in that thing.....

It's been on my mind ever since, can it be done to a level that can create a working forge? I had some thoughts on what it would look like from a blacksmithing perspective, but it may be way off from a rocket stove builders perspective.

I hate using coal and propane to do things and I am committing to building a forge from a rocket, but I need to ask for some help and input on how best to arrange the burn chambers to get it to work.

This is a sketch of my initial thoughts on the core shape and all, again from a smiths perspective.....is there enough heat up at the forge chamber?
image.jpeg
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allen lumley
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Chadwick Holmes : Here is a little more information, the 1st is from a Paul Wheaton podcast

http://www.richsoil.com/permaculture/2925-podcast-241-rocket-stoves-efficienc/

rocket forge portion starts at 5th paragraph but its all worth listening to !

Origionally there was a 4 DVD Rocket Stoves video set out there and I believe that it contains some footage of

Ernie working soft steel, There is in the works an 8 DVD set for those who have signed up for it via 'kickstarter' eventually

(this year) I expect that that set will be for sale to one and all !

I did find a lot of posts mostly speculating on the future of forging simply by using the Permies [ Search ] feature

And typing in ''rmh forge'' in our search engine ! Another perk of your membership ! God luck and good hunting Big AL

 
Chadwick Holmes
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Thanks big Al! Are you the sole responder on rocket stuff?! You seem to be the only person to say anything when I ask! I want to get enough firebricks all at once for a mass heater, The firepit I was bothering you about, and this forge, so I am working on planning them at the same time.

So I guess my question really comes down to:

temperature at the top of the riser? And how much flamey stuff can I get in the fire box?

J tube or L?

Will a box at the top interrupt the draft too much?

How do you push the temps at the top of a riser higher?

Is there a design flaw in how I am looking at it?

So, that's a lot but maybe I can get one or two of these answered without those steps in trail and error.

I was late to find the Kickstarter but as soon as the DVDs are out I'm buying them!
 
allen lumley
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Chadwick Holmes : You brought a smile to an old mans face ! Actually after 40+ years of just one basic design adapted over and over again to fit individual D.I.Y. Builds,

There has been an explosion of new ways to create a whole new range or types of rocket mass heaters and I am seriously in danger of becoming non-relivant.

So have you been to Rocketstoves.com to download your pdf copy of the new 3rd edition of Ianto Evans' ''Rocket Mass Heaters'',yet. ! copy to use, 1 to lose and 1 to

loan to a close friend - all one price !

This is ''The Book'', It will save you time. effort, materials, money, and frustration and you will be just a little bit better prepared to come back here to Permies.com with

your future questions ! All the math you need is all 4th grade stuff, no problem !


Any well built rocket mass heater RMH, should be capable of making the top of your barrel glow dull to cherry red if you push it ! Or you can take a large salad bowl as

a form and make an oven from several crumpled layers of Aluminum foil, The Thermal mass bench itself can be used to raise dough for bread that can then be baked on

the barrels top !

If you are going to place it within a home and want 24 hour heat at your location in western PA. then You want a 6'' J-bend Rocket with a large Thermal Mass, If this is going

into a workshop I would recommend the thermal mass anyway possibly with the introduction of a 1/2 barrel " Bell'' -to deliver more Prompt Heat . more later !

With the 6'' RMH as your starting place, a tall heat riser, and a 1.5'' to 2'' gap between the top of the heat riser and the barrel, the hot exhaust gases rising in the Heat Riser

slam into the barrels underside and roll in a doughnut shape giving up a lot of its heat to the barrel top and the upper 1/3rd of the barrel ~40%~ the rest going to your

Thermal Mass. So yes. the box would be a potential problem.

This does not mean that you can't make a simple rocket stove with a tall Heat Riser and no barrel and coal for fuel reach low forging temps inside that Heat Riser .

Just today fellow member and rocketeer Satamax Antone posted a new video showing the teardown and rebuild of an old 6'' j-bend style RMH to a include the installation

of a ''Bell' where previously there was only horizontal ducting through the Thermal Mass . //// see link below :


http://permies.com/t/52663/rocket-stoves/Rocket-stove-secondary-air


I took the liberty of sending you through another post as I have answered some of your questions more in-depth there ! Please note that I have a strong bias towards the

older style J-bend RMHs. Almost all of the batch box style rockets are less than 2 years old, are a harder 1st build to get right, and improvements or problems are both still

probable .

My recommendation for all 1st time builders is to follow a traditional build and live with it for a heating season -and then work on adopting any changes .

Call me an old stick in the mud, For the Crafts Big AL
 
Chadwick Holmes
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Thanks Al! I'll look at those resources!

 
Mike Cantrell
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So, I do a lot of forging (I have a gas forge set up at home, and I go to a weekly open-forge-night) and just a little bit of rocketing (i've built one working batchbox).

There are two issues that I expect to cause you trouble.

First, your typical forge is adjustable. I don't know how well you'll like working in a fire that's only full-blast.

Second, there's a reason you forge in coal or charcoal, a reason besides the heat. Burning wood emits lots of junk. At forging temperatures, steel is susceptible to absorbing junk. This can be problematic. Will the heat at the end of the riser be sufficient for forging? My guess is yes. Will the exhaust at the end of the riser be clean? With all the undesirable compounds destroyed? I really don't know. If I ever tried it, I'd be carefully, diligently, suspiciously watching for the symptoms of having contaminated my work with sulfur or other nasties.

 
Chadwick Holmes
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Yeah, I was thinking on that, sulfur is very volatile in that it doesn't like to stay in a form when energy is around free to use......meaning I am hoping that at the end of a rockety riser most of the compounds that would be an issue if you put wood in a coal forge and touched your steel to it would be gone......again it's a hope.

All this stuff came about when folks would use wood rather than charcoal for blade smithing, the wood touched and surrounded the steel in the forge, but charcoal is ok, the volitles are released in gass form when making charcoal, so one would think that the gasses that are reburning in a rocket are partially the very same ones that historically caused the issues. And have they oxidized and become compounds in the energy transfer of the second burn?

So, are you with me, am I a nut? I think it's worth a try, but I need to troubleshoot the forge "box" at the top to eliminate issues, that way we are dealing with one thing at a time.
 
Mike Cantrell
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Chadwick Holmes wrote: I think it's worth a try, but I need to troubleshoot the forge "box" at the top to eliminate issues, that way we are dealing with one thing at a time.


Definitely agree.

A few people have talked about this, but to my knowledge, no one's done it. Be a pioneer!

I like your box. That's pretty much exactly what I'd do.

- A bit of a chamber to catch the heat (better than just sticking the work in the exhaust path)

- Open at both ends to pass long pieces through

- Insulated a bit


Keep us posted!
 
Chadwick Holmes
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I was thinking the box is fire brick with a fire board top or something too.....

 
Glenn Herbert
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I would want the box positioned and shaped so that I could see the iron in the heat and know how hot it is getting without having to lean over or pull it out to check. With the opening oriented to face front to rear, there is the issue of exhaust pointing toward the smith. You might want the box shaped to allow more exhaust to leave at the rear.

The hottest, most corrosive part of the heat riser is the lower third, judging by the failure pattern of metal liners. Shortening the riser enough to be nearer the hot spot while letting enough combustion occur to minimize nasty compounds in the exhaust would probably be the trick. Some way of easily adjusting the riser height for experiments would be good, maybe 2" or 3" high rings of insulated riser... actually a mix of 2", 3" and 4" rings would allow extreme adjustability.
 
Chadwick Holmes
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Yes Glenn! That's perfect the ring idea is gold! I also figured that the whole thing would end up on a stand to bring it up to forge hieght, glad to have a second on that idea too!
 
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