Fun Furnace Picture

[Bovine]

Checking on the pot of hammer heads and carbon flakes before leaving them to carbonize overnight.
Makes me want a pizza!

 

[nfk]

Hi,
I got access to this kind of oven, it reach 1300c!
My wife use it to cook clay pots and ash keepers!
I always wondered if i could use it to melt aluminum. Should it work and be safe enough for it?
Any of you have ever used one for this purpose? Any tip?

Norberto

 

[robcas631]

Makes a fast Pizza!

 

[bhowden]

I use an electric kiln to melt aluminum. I added one of the PID controllers out of Hong Kong and a thermocouple to keep the temp where I want it. I put in a steel crucible and bring it up to temp first so the aluminum is not sitting there oxidizing as it heats. I add half salt (KCl _ NaCL from the grocery store) as a flux. I get a bit more dross than I did with propane but it is a lot cheaper and quieter.

Brian

 

[nfk]

Nice I'll give it a try.
Should i configure the PID with any special setting? The oven already has a chinese PID controller but all the settings are for clay and go up to 1200C in a slow ramp.
How much salt per alum Kg do you add?

I've spend the last 3 years collecting alum from old cylinder heads and engines! i got about 200Kg of scrap waiting to reborn in something else!

 

[bhowden]

I have not used it a lot yet but so far I have just set the temp without the actual PID functionality. (ie on / off mode) I am still trying to figure out how to calibrate the temperature. The crucible is glowing at a colour of red that looks to be about 100 C higher than the controller is indicating so I just went with how liquid the aluminum was. I did not measure the flux or weight of aluminum exactly but I would guess it was about 12 ml per kg. The crucible is about 100 mm id and will take up to 250 - 275 mm in height but so far I have only been filling it half way. Don't forget to unplug it when you open it as the coils are all live when it is on. You don't want a 220 volt shock when you are holding several Kg of molten aluminum. You don't normally open a kiln when it is hot so I am a little concerned about themal shock or oxidization reducing the life of the element but so far, so good. The brick is quite fragile so I made a shallow steel tray to go in the bottom to catch any slop or spills. Not sure if it helps but I painted the tray and ouside of the crucible with kiln wash.

Brian

 

[nfk]

Thanks, I'll follow your recommendations.
I'll build a crucible out of a 5 inch pipe, it should be OK to experiment and maybe cast a few ingots.
If it work as expected, i'll go bigger!

My wife yelling at me in 3, 2, 1....
Molten alum: priceless