Electric forge for casting 45 lbs barbell plates

[Mario prefontaine]

Hey, so my knowledge in forges and smelting is pretty minimal. But my goal is to have a forge big enough to be able to melt 45 lbs of cast iron in one crucible. My goal is to be able to sand cast 45 lbs dumbbell plates. There is a unit that I found from a company in USA called pcm supplies. I phoned the company and they say that the forge I was looking at would get to the melting temps I would need, but it says that the forge runs on 110 volt 3 prong standard plug in. I just have a hard time believing that with 110 volt I would be able to reach those temps. Would anyone have experience smelting and casting cast iron? And what do you guys think of this forge? 
 

 

I have attached a picture of the electric furnace and it’s description. 

[Steve Sells]

you seem to be confusing the terms for forge and furnace, you need to use correct terms to get correct answers, they are not the same,

As  for your other issue, 120v isnt going to get very much power on a standard 15 or even a 20 amp circuit because they only have 1800 and 2400 max watts respectively

[Latticino]

Melting temperatures for casting iron are much higher than for casting brass, and consequently it needs lots more power input and is MUCH more dangerous.  I find it pretty unlikely that  a standard 20A 115 V circuit (2.3 kW or 8 MBH, as a comparison, my forge likely is around 200 MBH and still can't melt steel, but would likely be able to melt cast iron at high fire) would be adequate to melt 200 lbs of brass, much less cast iron.

Cross posted with Steve, who I completely agree with.

As an aside, for the energy expenditure, safety equipment required, and risk I can't imagine casting one's own dumbell plates would ever be economical.

[Frosty]

The short answer Mario is NO, no way. I'm not dissing you but you don't know enough about casting to do it safely with even low temp metals. Molten metal is extremely dangerous even with proper training, equipment and PPE. Molten iron is as dangerous as it gets. 10lbs. of molten iron has the explosive energy equivalent of half a CASE of 40% dynamite and YES you can release that energy about as quickly as dynamite explodes. 

The amount of explosive energy of 4 1/2 X as much molten iron is NOT 4.5x as much, the force release is more like the square. I used to have an instructor who had all this stuff at hand but I haven't been in metal shop in 50 years.

It's good to have ideas Mario but the secret is knowing your limits. I'm sure if you put your mind to it you can cast dumb bell plates and many other things but not now. 

Frosty The Lucky.

[ThomasPowers]

Going electric would be very very expensive!  Have you looked into a cast iron melting cupola furnace?  They can be built and run by a couple of people.

Note in English smelting is taking ore and making metal from it. If you want to melt metal; it's just melting.

[Mario prefontaine]

54 minutes ago, ThomasPowers said:

Going electric would be very very expensive!  Have you looked into a cast iron melting cupola furnace?  They can be built and run by a couple of people.

Note in English smelting is taking ore and making metal from it. If you want to melt metal; it's just melting.

No, I have not really looked into cast iron melting cupola. I will have to do that, also I’m ok with spending around 6000$ on this project, and it just seemed from a beginner perspective, that the electric would be the most Efficient. But I could be completely out to lunch. And thanks for clearing that smelting and melting. I was getting a lot of xxxx for mixing up my terms. 

[Steve Sells]

When you joined you were directed to read a few things, then you signed a legal document stating you read and agreed to follow our rules.  We are serious about them, Language is one of those, this is a G rated family friendly forum watch your language, I edited out your mistake

[ThomasPowers]

It gets rough when you throw in different languages; I know a couple that use the same term for both coal and charcoal and since both are forge fuels; that can confuse a discussion fast!

[Buzzkill]

2 hours ago, Mario prefontaine said:

My goal is to be able to sand cast 45 lbs dumbbell plates. There is a unit that I found from a company in USA called pcm supplies. I phoned the company and they say that the forge I was looking at would get to the melting temps I would need, but it says that the forge runs on 110 volt 3 prong standard plug in. I just have a hard time believing that with 110 volt I would be able to reach those temps.

I have limited experience casting and have never tried cast iron.  However, I do know that you need to be able to melt more material than your finished product will weigh.  Typically there are risers, sprues, and/or runners which will contain some of the melted metal, so you need to compensate for those things.  In addition most castings require some cleanup or machining which will also reduce the final weight.

I have built a heat treating oven which uses 110v.  I built it to pull slightly under 15 amps.  Just to heat the interior of the oven up to 1950 degrees F takes about 3 hours.  That's for a space much smaller than you would need, there's no big heat sink (crucible) to add to the time, and it's still a few hundred degrees below the temps you would need.  The bottom line is you were right to be skeptical about that furnace being suitable for your desires.

I know you're probably already tired of reading it, but what you want to do is extremely dangerous and is far from a beginner's project.  If you're serious about casting you should start with easier metals and smaller projects to get some experience before diving into the deep end of the pool.  Aluminum and brass casting are also dangerous, but less dangerous than cast iron.  If your budget is $6,000 USD you should be able to get the proper PPE, but I would also highly recommend using a portion of that budget to take a casting class or get some other personal instruction from someone who has experience doing what you want to do.  You're much more likely to get the results you want and avoid serious injury or death that way.

[SLAG]

The SLAG,

Suggests that one more precautionary step should be added to the many Mr. Buzzkill has mentioned.

That is namely:

Get an attorney to prepare your last will and testament so your next of kin will be properly taken care of.

Good luck!

Sinceriously ,

SLAG.

Foundry ...  can be fatal.

 

[Frosty]

2 hours ago, Mario prefontaine said:

I was getting a lot of xxxx for mixing up my terms. 

You need to get a LOT more than terminology right before doing any casting let alone iron. If you won't do more than read a sales brochure or two before attempting dangerous pursuits then you're cutting the line for a Darwin Award.

Take a class or two at least. $6,000 is barely seed money to get into iron casting. I don't think it'd cover the hand tools but maybe if you know how to make some of your own. There's equipment you'll need other than the melter.

What kind of sand do you want to use and how are you planning on preparing it? Know what mulling and screening are? The different sands are bonded differently and require different handling and curing treatments. 

I'm no caster though I've done a little and the list of tools, equipment and skills coming to mind would cost more than $6000 on several fronts. Schooling and materials charges would run to that anyway. Equipment to prepare the  mold material is well more than that. A few sacks of molding sand alone will cost a few hundred. Let's say you make and hand riddle the sand and hand tamp you can make that equipment for call it $150 if you have the tools to do it. Oh heck you can use: hand saws, Elmer's glue, rasp, sand paper, drill and maybe get away for under $100. You'll need to buy the tool to cut sprue and riser, they need to be tapered and you can't cut sprues and risers with a knife or it loosens the sand and will ruin the casting. The knives for cutting gates and runs are no big deal, call those a gimme.

Lost wax investment casting is an option with a higher chance of success for a beginner but still handling 50lbs of molten iron to cast MAYBE 45 lbs of barbell weights is dangerous enough you really should take Slag's suggestion before you start.

Frosty The Lucky.

[George N. M.]

I realize that you are getting dumped on by everyone saying this is a BAD idea.  This is because it probably is a BAD idea.  Casting iron just doesn't work out well as a home hobby.  The equipment and danger are just too much for anything smaller than a commercial foundry.  Something like this would probably void your or your landlord's property insurance in a heartbeat.  

Another thing to mention is that handling 50 pounds or so of molten metal is something that would take a minimum of 2 people with LONG specialized tongs to carry a crucible and pour the metal.  I suppose you could have a furnace that you tap like a blast furnace and let the molten metal run in a channel to a mold but since you are talking about a crucible I don't thing that is your idea.  Again, a very dangerous process and most modern foundries do this by remote control and keep people out of the danger zone.

Do as you want and take or reject our advice but as Frosty says, if you go forward you are cutting the line for a Darwin Award.  Do you really want to take yourself out of the gene pool?

"By hammer and hand all arts do stand."

[Irondragon Forge ClayWorks]

Not knowing where in the world you are located. I would suggest checking with the local authorities about permits that may be required.