Electric smelter idea

[sammorgan3]

Check my thinking here guys.

Flat bottom cast iron pot with a stove element brazed to the bottom along with a brazed K TC. PID control set to 700 along with some insulation should prevent melting in zinc. Worth a shot for me to prototype?

[blikseme300]

Not sure if brazing the element to the cast iron pot is a good idea as I have seen cast iron crack easily after being brazed.

A number of members here have built their own smelting pots and I can't recall any using cast iron. I copied ideas from the work others have done and black steel and SS are the materials I used. The way I did it is documented here: http://bliksemseplek.com/boolits.html

[sammorgan3]

Duly noted on the cracking. I know CI can successfully be brazed or welded with a slow ramp up and down in temperature, I'll have to look into it. Already have a cast iron 5qt dutch oven with a flat bottom, seems would be ideal. Would rather braze for thermal transfer between element and pot, perhaps something else will work. Braze element onto a steel spreader plate with Tcouple embedded in the middle? My thinking is if the heat source never passes 700* then zinc shouldn't be a problem, just dump skim and pour ingots. Of course melt times would probably be slower due to DeltaT being lower but with insulation probably not too bad.

Edit: That Mother of All Melters is insane!

[Idz]

I believe your typical stove element is about 6 kW which translates to 20,000 BTU/hr . Turkey fryer burners run about 35,000 BTU/hr and I use a weed burner torch that can put out 500,000 BTU/hr. With my insulated propane tank pot loaded with about 100 lbs of scrap it takes about an hour for a melt with my torch running about 50,000 BTU/hr. Electric is fine for small batches or if you're patient but to go into production you'll want something bigger.

[country gent]

Another issue with brazing will be the diffrent expansion rates between materials, the heating element, cast iron, braze. Alot of the electric elements are bands or inserts that are wraped around or set into holes in a plate. MAybe a false bottom with the element in it.

[ssnow]

I like the idea of a large electric smelter, basically for more economical operation, and you would avoid all the hassle involved in propane bottles. If I ever get around to building one, I would simply use steel, and avoid cast iron.

Yes, many do use cast iron pots so they certainly work.........but I would not have to worry with steel breaking, and besides, steel gives you a lot more options. You can use plate and make it whatever size you want, or there is a lot of pipe and tanks available fairly economically.

[craig61a]

I do recall seeing a pot that someone built using electric stove elements - ah... have a look at this thread:
http://castboolits.gunloads.com/show...t-Construction

[dikman]

I wouldn't have any confidence in something like that. Welding/brazing cast iron is problematic at best and when it's subject to heating/cooling cycles like that I reckon you're asking for trouble. Maybe if you bolted the element somehow to the bottom?

[Handloader109]

If it was me, I'd do something similar to blikseme300. You can get cylindrical heating elements pretty cheap. And I would stay away from cast iron

[sammorgan3]

Hm. Perhaps something simpler? Like a large PID controlled hotplate? Could even remove the lead pot and put the big 40gal crawfish pot on it then!

[sammorgan3]

Cylindrical element would be nice wattage wise. Would have to build a steel pot though. Biggest pipe I have laying around here is somewhere around 5.5OD x 1/4Wall. Not really as big as I wanted, would make a tall skinny pot that's difficult to work in.

[dikman]

Yeah, tall and skinny isn't good when you're dealing with a lot of hot lead! Not the best, stability-wise.

How about a propane tank, cut the top and bottom off and weld a piece of round steel plate in the bottom. Then you could attach your heating element to the bottom.

[sammorgan3]

I was just having thoughts along these lines myself. 8" round of 3/16 welded in to flatten off the bottom would work and could get more capacity. I can save my dutch oven for chile. Steel would allow easier thermocouple attachment as well, just weld on a nut.

[sammorgan3]

http://castboolits.gunloads.com/show...1-Lead-Smelter

Well this guy seemed to have good luck with a stove element. Basically what I've got in mind + engineered stand and PID control.

[bangerjim]

Welding on those elements will probably ruin them. And the CI warnings above...ditto!

I still feel nat/propane is the best way. Fast, easy to control, high BTU concentration. Much faster and more efficient than anything electric. Why do you think pro chefs use gas stoves? You never see electric stoves on pro cooking shows!!!!!! You can't beat a blue gas flame.

Electric is perfect for casting.....would not have it any other way.

Good luck in your search for the perfect illusive electric smelting pot!

banger

[dragon813gt]

Has anyone sat down and done a cost/benefit analysis. I'm able to smelt hundreds of pounds on one tank of propane which costs $20. I pay around $.075 per kWh for electric. I would have to sit down and do the math which would be based on the heating element size. And the BTUs needed are dependent on a lot of environmental factors. I think propane would be cheaper if I did the math.

[angus6]

buddy did the math last year when we built a 17.5"l x12"w x 10"d pot , worked out cheap enough

[bangerjim]

With Obummer shutting down all the coal plants in the next couple years, your electric bill will far exceed the cost of a tank of propane!

banger

[sammorgan3]

My point with the electric smelter was to never let the bottom of the pot exceed 700*F. Therefore no sorting required before smelt. Maybe pick out stick ons if you wanted.

[bangerjim]

My point with the electric smelter was to never let the bottom of the pot exceed 700*F. Therefore no sorting required before smelt. Maybe pick out stick ons if you wanted.

But.......sorting is half the fun!!!!!!!!!!!!!!!!!! HA.......ha!

Actually I hated it when I used to mess with ww's. Not any more, I mix all my alloys. If I want something close to ww's, I make it.....all from clean pure alloys.

good luck with that pot.

banger