Outdoor Rocket Kitchen

[fzurzolo]

Hi All,

This is my first thread on this forum and it's my first rocket build ever. Many thanks to Donkey for the inspiration for this build and of course all the other contributors that led to the development of these great burners!

After using my cob oven successfully for about 4 years I became very interested in the possibility of building a complimentary rocket powered burner so I could do things like fry and grill without constantly burning the backs of my hands/arms on the hot oven arch (those who know what I'm talking about say "I"). 

After sourcing some clay from a friend's fencepost install, some insulated fire brick from a local pottery studio that had just redone their kiln, and a bunch of slop clay (from the same studio) I was ready to build. The basis is a (150mm) 6" system moulded around some 6" stainless vent pipe I had from a bathroom reno.  My burn tunnel is probably a little long as you can see from the pics but I find it still works great.  I need to redo the feed tube as the clay isn't tough enough to handle the sticks banging into it.  I still have to put on a final plaster on the cob/perlite sections but I'm waiting to get my roof up first before I do it.

No barrel was harmed in the making of this stove.  The top cooking surface is a cast iron pizza pan (14") that I got off Amazon for $25 and then a cob formed flue directs the gasses under my boilin' pot and out to what will eventually be a chimney (probably coffee can type, or similar, coated in cob).  I've been cooking on it since I had the chimney up and I can say now that the cob is dry, I can fry and boil at the same time, or put a pot on the cast iron and do 2 pot things at once. 

For anyone that is wondering between the cob oven and rocket stove, I'd say that it's best to have both .  The rocket stove can't bake like the cob oven can (I've got about 3" of heat retentive clay followed by >4" of lime-perlite insulation in the shell and base of the oven) but the cob oven can't grill or fry as easily, and certainly can't boil things like the rocket stove can.  And the tiny amount of wood used to cook on the rocket stove is still baffling to me.  Maybe that's the best part.  Or maybe it's the no-smoke after the first few minutes part.  Both are great.  Anyways here are the pic's on my google drive. 

drive.google.com/drive/folders/0B8B1nNJ4O7d8TFJieEhtdUxxOEE?usp=sharing

 If I figure out how to easily host them somewhere I'll post them right on the thread.

Ok now for questions:

-->Has anyone done lime plaster right over the cob or is clay plaster better?

-->Any good ideas on a stronger feed tube or should I just use brick?  I was thinking about maybe taking the bottom out of a properly sized terra-cotta pot.

-->And from what I've read, secondary air in a traditional J-tube rocket isn't really necessary.  Is that true?  Anybody with experience on this could help save me the effort of doing something useless to the stove if I don't have to.

Many thanks again to all the contributors on this great (and reasonably addictive) forum!

[pinhead]

I haven't done lime plaster but I've heard that's a bad idea - since the lime will harden while the cob stays fairly soft. From what I understand, this difference will cause them to separate.

Like I said, I've not done it, so more research is likely needed. IIRC I've seen people do it - but haven't seen any long-term results.

When you say "secondary air" what do you mean, exactly? If you mean "fresh air added after the burning fuel," then you mean tertiary air which works wonders on the standard J-tube. Look up the development of the P-Channel on the forum.

[fzurzolo]

Thanks Pinhead,

I see the p channel in the j tube, along with the trip-wire development. I will be incorporating that into the stove as I fix the feed tube. In terms of primary, secondary, and tertiary air, I found this explanation presented by Karl (no longer a member).  Is this also what you would say is a correct description of the different points of air supply?

donkey32.proboards.com/post/9616/thread

If so, then I get it.  And would you also agree that J-tube rockets don't need primary air? 

Turns out mine has only secondary right now   Still burns pretty well though.

[pinhead]

Sept 15, 2017 6:52:20 GMT -8 fzurzolo said:

Thanks Pinhead,

I see the p channel in the j tube, along with the trip-wire development. I will be incorporating that into the stove as I fix the feed tube. In terms of primary, secondary, and tertiary air, I found this explanation presented by Karl (no longer a member).  Is this also what you would say is a correct description of the different points of air supply?

donkey32.proboards.com/post/9616/thread

If so, then I get it.  And would you also agree that J-tube rockets don't need primary air? 

Turns out mine has only secondary right now   Still burns pretty well though.

Yes, that post is where I got my terms as well.

Performance of a J-Tube can be destroyed with the addition of primary air by this definition; only secondary air and tertiary air are needed for optimum combustion.

I was amazed at how much more easily the J-tube started after adding the P-Channel - it improves the performance of the J-Tube in every conceivable way.

The same can be said about the P-Channel in the batch box.