Donkey I'm not sure about placing this on this part of forum,so please move it if necessary. Been jumping around the forum and talked about the possibility of melting aluminum.After asking Peter about temps at the top of insulated riser tube,it seems like it could be done. Of course there are some questions(go figure LOL!) If a core similar to the Peterberg dragon type was used below a chamber similar to the institutional cooker design insulated like the riser with a lid to contain the heat. It seems to me it could certainly melt aluminum. Suggestions?? Presently I'm using a waste oil burner in a homemade foundry furnace. It requires a preheat with Propane and a blower to melt. Being frugal(read cheap)it seems like using a rocket stove for melting would cost less and be greener.A further idea will be to used pressed oak saw dust and news paper for the fuel would be even greener if it could produce enough BTU's. Suggestions?? Currently I have a rocket stove built of a section of a 30 gallon water heater. It has a 4.5"feed tube,3"X6"X18"fire box,6" dia.X24"insulated riser and 4"dia. exhaust pipe.The fire is smokeless in less than 10 minutes and it's heating my garage/shop.Originally was going to convert it for metal melting but have decided better to leave it alone and build another for melting metal(plus building and firing these is great fun). Please offer any and all suggestions you have.... Thanks in advance. Don
Heh.. I've got a WVO foundry as well and I love the thing.. I know, they're smelly, dirty, tend to splatter hot oil around. etc.. I fire mine with wood to get it started..
The issue with the rocket stove is going to be it's consistency. The place where it's hot enough to CONSISTENTLY melt the metal is down inside the heat riser, about a third from the bottom. 'Course, taking heat from that place is exactly NOT what to do in a rocket stove, it will reduce efficiency of burn by a LOT. It is possible to create thermal runaway.. I've seen the tops of barrels turn cherry red, I've seen 1/4 inch plate steel writhe around, etc.. I just don't see these things happen on a consistent, every time you run the machine kind of basis. Not yet, though perhaps through Peterberg's new additions, it may be possible to do what you are thinking.
You'll need to make a stove gets immediately into thermal runaway mode and stays there for the duration. It maybe doable. It's a tall order.
Thanks for the quick response guys. Guess I'll need to research the "thermal path",'cause I'm ignorant about it(and a lot more!!). Glad to hear about your foundry Donkey. If you're interested I think my web site is still up but probably not much longer(tired of paying for it I guess).Anyway give it a look,it was a vain attempt to cover the costs of my hobby and just covered the cost of keeping it up so will cease to exist when current funding run out. www.blindpigetc.com Again thanks for the suggestions.... Don
Post by matthewwalker on Mar 26, 2013 9:42:30 GMT -8
Love the bookends! I'm not sure if this would work, since I know nothing about metal foundry, but...
My outdoor cookers are basically standard rocket mass heaters, either vertically fed or horizontally. On top of the barrel I have a hole above the riser, with an adjustable baffle. I have built small insulated masonry ovens on top of this configuration. Upon burning out the form for the oven, I will often "fire" the oven by continuing to feed the "top fire", which is coming out of the hole on flashover, with more small wood. By doing this, I've achieved some seriously hot fires up there on top of the barrel, in an insulated masonry chamber. It completely disappeared a beer can in a matter of three seconds or so. Maybe that will give you some ideas. Here's a photo of the "oven" to help you visualize.
MW, thanks for your info. Do you think if the oven on top was an enclosed insulated cylinder with an insulated lid that the temps would climb without the added wood? I realize I'm asking for an estimate on your part but think the estimate(guess) will be enough encouragement for me.... Thanks also for the bookend compliment,there's a lamp with a couple of those little guys on it as well now. If you've melted aluminum cans in your oven can some casting be far behind? Again thanks, Don
Post by matthewwalker on Mar 27, 2013 9:37:34 GMT -8
Well, I do think you could most likely heat that insulated chamber to aluminum casting temps without the top burn. As the fellows were discussing in another thread, on flashover there is a column of flame shooting a couple feet out of the top of the barrel. By putting it up there, and retaining the outer barrel as the flue path back down, I think you'd have a good shot at getting it to work.
ericvw: Got that right, sista Daryl!
Apr 10, 2015 16:57:57 GMT -8
Daryl: I'm off on a hike...everyone have a good day!
Apr 12, 2015 7:40:50 GMT -8
ericvw: So Daryl, to where did you hike?
Apr 13, 2015 14:21:38 GMT -8
Daryl: Along the French Creek. Ok, it was more of a walk...but still! I got outside!!! And it was in the 60s, cool, and breezy! If it doesn't rain tomorrow, then I am going to try to get over to a lake. Just smelling the fishy water will be a buzz!
Apr 13, 2015 15:38:28 GMT -8
ericvw: Everyone in the states doing there taxes or something? Perhaps Spring has sprung... Boards are quiet!
Apr 15, 2015 16:18:19 GMT -8
Daryl: Warm and the sun is out = quiet boards.
Apr 16, 2015 5:08:56 GMT -8
ericvw: We've been in the rain for DAYS! And not warm rain, either
Apr 16, 2015 14:57:18 GMT -8
Daryl: You are two states south of me! You're supposed to be warm! Stop it!
Apr 16, 2015 16:14:09 GMT -8
ericvw: Talk to the hand, Daryl! You can handle being two states above me, this I know! Did you catch that buzz off the fishy creek, or is that what u youngsters call it these days?(rofl)
Apr 17, 2015 17:44:41 GMT -8
Daryl: Ooooo snap, Eric. Nah, I get high on nature...and ice cream.
Apr 17, 2015 18:16:53 GMT -8
Daryl: Well, I got a growing pile of sticks in the back getting ready for burning. Windy here.
Apr 21, 2015 12:03:16 GMT -8
ericvw: I got a growing pile of logs and buckable limbs in the back- windy and intermittent rainy here, going back down into hi 30's- lo 40's overnight. Guess I'll be firing up the old iron box! Need to get that batch box built this summer!
Apr 21, 2015 17:52:25 GMT -8
Daryl: Yep, 30s overnight here too this week. Crazy. We will be lucky to get 4 months of steady weather over the 60s. I only burn in the summer so I am looking forward to cooking outside soon.
Apr 21, 2015 20:55:27 GMT -8