Bulk Scrapping Furnace

I gave up on the stack melter because of the sorting, Jeff.

 

Here's an idea:

You'd need a ready supply of graphited ingot mo(u)lds.

Also, you'd probably want to keep a neutral flame going on the drippy side to keep the melted alumin(i)um flowing into the mo(u)lds.

Advantage is you'd get little extraneous "stuff" in your alumin(i)um, compared to some other stack melters.

Trouble is, this kind of construction almost mandates a fair volume, i.e. you and several other casters in your area pool resources to run such a beastie - as one of these things could do hundreds of pounds/kilos in a campaign!

 

Same here. I must be a glutton for punishment because I went back for seconds and that sealed the deal.
Slicing with a circular saw or table saw leaves swarf everywhere but I'll go back to it if my modified stack melter takes too long or just fails.

Andy, you're running oil, build you one of those Glumpy flame throwers. He melted that head in no time.

 

Interesting. Bonz mentioned a rocket stove earlier. I'm not sure if this is what he had in mind but this could be the solution to ashes and charcoal in the pool if the ashes are contained in the burner box.

Pete

 

I think Kelly has it right. This one time.

A wettable refractory with a reverberatory flame seems the easiest way to go, with steel left in the bottom for cleanouts. The solid fuel chimney design seems to me you could melt steel at least if you are firing it hard and do some serious aluminum contamination. Ideally melting into a hot crucible which could be poured into ingot molds. Definitely a free fuel bonus operation.

 

OK. Cans are out. That clears out a corner of my shed. Make friends with a mechanic. Check.

 

Glumpy
You guys probably miss hearing his voice.

 

Note: solid fuel is not a requirement. You could use a Glumpy creation for the main fire if you wished. The reason I wrote of solid fuel in that location was for those who wished to dispose of tree-trimmings and the like. (E.g. Tobho, as he wrote earlier)

The reason for the long 'stack' on the drawing is to extract as much heat from the fires as can be readily managed.

Note also that the bottom, at least, looks like a prime place to use used/salvaged hard-brick. Upper parts might use the Gingery mix of 2 parts sand to one part fireclay. (? I think Gingery spoke of it in one of his books. The chief issue is its suitability. Unless you are Art in Spokane, (he sells ingot) or doing a lot of casting, you'll probably not use this contraption more than a few times a year.)

Speaking of mo(u)lds - I have a few already, including a "corn" mo(u)ld and another old cast-iron piece. If I make more, though - I'm thinking 1×2 c-channel, to fit smaller pots more readily.

 

That is what I'm doing with the fire box in the back. The flames will go through the opening in the wheel chamber.
Where I've built it is a natural wind funnel and if that is not enough, will add a blower.
I've got enough wool to line the drum and add a second skin over the wool.
Need to do a test burn first when the weather breaks.

 

A couple things put me off to the Glumpy idea. One, no I don't miss his voice, although he makes some serious heat with those burners. The other is the dross. I do some scrapping in a reverb fueled with waste oil and get quite a bit of dross. The furnace is similar in design to Yoda's except not a direct flame on the metal. The burner plugs into the barely visible hole in the left end and the burn takes place mainly in the enclosed chamber. Flame comes into the main melt chamber along the top and generally terminates just below the access hole which is about half way across and also barely visible in the picture (it has its plug in it as well). It's pretty effective, but as I said, I lose probably 10% to dross. Even though the flame isn't "directly" blasting the metal, the bath is still exposed to the products of combustion. So, I think it's because of the oil. My point is, as others have pointed out like Tohbo and Donkey, the DRIPS from the wood-fueled stack melter don't seem to produce that kind of waste. I highlight drips because they may experience a residual mess inside the melter when the day is through, but the collected metal seems to be pretty clean-melting. This has been my experience with stack melting with wood as well. I know it seems counter-intuitive (as Kelly mentioned surface area), but it doesn't seem to be the case. I'm thinking that the oil vs the wood may make a difference.

Pete

 

I found the labor with the bulk melter dripping into water with charcoal to be the biggest deterrent. Recovery ratio was not too bad but the labor saved in not disassembling heads and blocks or cutting up wheels far offsets the loss of aluminum for me.

In doing microscopic analysis of my melts I have found that melting gassy ingots results in a clean pour. I use no degassing and get clean pours. Although we've discussed this before I want to reiterate for new members. I've melted window frames with plastic on them, aluminum cans with all their problems, and aluminum castings I couldn't get clean. There is a lot of dross and the ingots are full of porosity. When those ingots melt I find the porosity does not persist. If the porosity is bifilm it must float out. If the porosity is hydrogen or another gas I surmise that at the melt front the aluminum ingot is only at melting temperature so it has little affinity for gas like it does at higher temperatures. I have sectioned many ingots and castings and find I get clean castings from a second generation ingot and pretty good castings from a first generation ingot. I guess that makes me a bull. Or is that bull-headed...

I do have videos showing the results. And no, my castings are not completely void free like most automotive castings I've cut up but they are certainly clean enough to hold water pressure. My test pipe from a few years ago is still at about 40 psi with two o-rings and a valve.

We obviously have experienced different results and I can't explain that.