Would Appreciate some advice on "Electric Furnaces"

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wa8dof

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Hi Guys

I have been casting aluminum parts for several years (mostly successfully) using a "Ginery style" Charcoal Foundry. As you know, it works well, but is a "fair weather" operation and difficult to do in the winter, especially here in the Upper peninsula of Michigan.

I am rebuilding my heated workshop and have a corner set aside for casting operations so that I can pour "year round". Since I don't want to burn charcoal inside the shop, I am considering an Electric furnace and was hoping to get some advice and maybe some "war stories" from those that have "been there and done that". Am interested in your experiences, brands, cost, power requirements, venting, etc.

I am not adverse to building an electric furnace if I can find the heating elements, but would probably just buy a commercial product if it meets my needs.

Anyone have any advice for me? Thanks for reading.

Dave
 

William May

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If you are going to do small castings, I would check into a small electric crucible furnace from Rio Grande. They are normally used for jewelry pours, but I bought the biggest one and use it for brass and aluminum pours in lost wax/plaster. You can use this on top of a table, although I would suggest it be a metal top table.
Look at their catalog and videos, and you will be impressed.
Now, go down to a local jewelry supply shop, and ask to see their used equipment. Most jewelry and lapidary supply places have shelves set aside for used items that were traded in on better or bigger equipment, or the items are from estates and the family is liquidating them. These are a good source of relatively cheap equipment, the only drawback being most of it will NOT have a warranty. The good news is that any reputable shop will have checked out the equipment and they will make sure it actually works. You can find the same stuff as in the Rio Grande catalog (It may even be equipment from them)
If you are thinking about a larger furnace, such as an induction furnace, you will have to modify the power that comes into your house. Industrial power
(480 volts) is what is normally used in induction furnaces, and they use a LOT of power. The key thing is they melt in a couple minutes, whereas a gas or propane furnace takes 20 minutes to heat a pour aluminum, and 30 minutes for brass.
I have seen some amateur-built induction coils, but I don't know how successful they have been. I think most of them use two 12 volt batteries in series, for 24 volts, but I don't think they will melt very much.
The good news is that 480 Volt power is really cheap. Power companies love to sell that power, and most industrial users are set up for it.
HOWEVER, you will probably have to have it specially installed, and then you will face a minimum charge each month for the 480 volt power.
Unless you are going to pour all the time, and you are going to sell a LOT of castings, it will not be worth it.

I have the same problems as you, except for me it is the summer heat of 120 degrees. I really don't want to pour in that heat, so I either try and pour in the off season (In Tucson, October through May) or if I have to pour in the summer, I pour in the early morning, using my gas foundry furnace.
If you only want to do small castings, or you want to do a bunch, but one at a time, you can start with as little as a propane or acetylene gas torch with a rosebud tip, and a small hand crucible from the same jewelery supply stores I mentioned above. You can buy a small amount of casting sand from Rio Grande, (They sell a sand called "Delft Casting Sand" (It is so fine, that it will pick up fingerprints when you mold it. I poured a speedometer fitting for an antique car with it, and not only did the "Stewart" logo come out, but also my fingerprints on one section.) (From a big casting angle, that type of sand is way too expensive to do a large casting with, HOWEVER, for learning and trying things out, it is ideal. it comes in a one or two pound package, and costs about $10-$15 per lb.) If you want industrial molding sand like Petrobond, you will have to buy a drum of it, which is usually 85-100 lbs. of sand. That is how I buy mine.) but with a hand crucible, put a plumbing faucet or bronze pipe fitting in the hand crucible, then put the torch in a holder, and turn it on. Use gloves to hold the hand crucible tongs, keep the crucible under the flame until it melts, plus a minute or so, and then pour your little mold. You can start casting for as little as $100 for all the stuff you need, probably less if you have the torch and rosebud tip already. And it will give you a good taste of foundry work. It's nice to start on a small scale, as a #8 crucible full of molten aluminum can be pretty daunting, unless you have gotten used to it.
Good luck.
 

abby

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You could consider adding a chimney/flue to your existing set-up , a 10ft x 6in flue will provide sufficient daught for decent sized crucible furnace and take any fumes outside your shed. This would be my first choice as it is so quiet and peaceful. However coke is no longer available in the UK and the charcoal is mostly the barbecue variety which is not ideal.
I use a propane fired furnace with a melt capacity of around 20 lbs bronze , this is inside the workshop ,with a short flue through the wall to outside .
On a casting day of say three melts I would not do any other work in the shop for several hours because of the uncomfortable temperature.
This lost-wax brass casting for a GWR castle class 5" gauge locob weighs around 4 lbs.

 

LSEW

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You may want to consider a used ceramics firing kiln. I think they have adjustable temp settings.
maury
 

WOB

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I have had a Neycraft Fiber Furnace (Neycraft Fiber Furnace - American Jewelry Supply) for many years. It has performed well for my purposes( heat treating). The ceramic fiber muffle is durable and light weight and I have never had a failure. The manual control takes some time to get a precise temp setting, but that is usually not a problem for a hobbyist. The control knob works like an electric stove burner controller. The insulation is very good and little heat escapes into your shop. It will run on a 15A circuit.

After a few years, I converted mine to electronic control using a tiny Fuji PID controller that fits in place of the meter. It was very easy and much improved the convenience and usability of the furnace but is really a luxury that is not mandatory for hobby use.

WOB
 

Richard Carlstedt

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There is a nice jewelry supply operation near you in Norway Michigan
called Kingsley Supply. I have used them years ago- nice people

If you do aluminum only , then electrical kiln is easy
Rich
 

wa8dof

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Thank you for all the input guys. You have given me a lot to think about.

I am also reevaluating my plans, and may go with a propane fired furnace with a hood and vent to remove the fumes from the workshop. So many options!

I am also thinking about sand. I have been using some used foundry sand from a cast iron foundry that was once located in the area. It has worked for many years but never gave me a nice surface finish. It is just too coarse. Thinking about making or buying a finer sand or switching to petrobond.

Winter is slowly leaving (snow in yard is down to 18 inches) so shop renovation and foundry work can soon commence. I have a few patterns made and am working on others in preparation for good weather. If I can move the operation inside, then I can pour in the winter.

Thanks again for all the advise. I really appreciate your time and thoughts.

Dave
 

William May

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Thank you for all the input guys. You have given me a lot to think about.

I am also reevaluating my plans, and may go with a propane fired furnace with a hood and vent to remove the fumes from the workshop. So many options!

I am also thinking about sand. I have been using some used foundry sand from a cast iron foundry that was once located in the area. It has worked for many years but never gave me a nice surface finish. It is just too coarse. Thinking about making or buying a finer sand or switching to petrobond.

Winter is slowly leaving (snow in yard is down to 18 inches) so shop renovation and foundry work can soon commence. I have a few patterns made and am working on others in preparation for good weather. If I can move the operation inside, then I can pour in the winter.

Thanks again for all the advise. I really appreciate your time and thoughts.

Dave
If you haven't used Petrobond, I highly recommend you try it out. It is great to use, and you will see a big difference in the finish on your castings. An 85 lb. drum doesn't cost that much. (But you might want to just go pick it up from the foundry supply house, if you can, as it will save shipping.) I drive from Tucson to Phoenix to get my drums of sand, from a company called "Porter-Warner Industries." The reason I like them so much, is that, although they deal with the big foundries in Arizona (The copper mines pour hundreds of tons each day!) when I first approached them, they treated me as if I was a big business, even though I am just a one-man shop. They really have bent over backwards to handle my tiny needs, give me good advice, and show me better ways of getting good castings. They are my favorite foundry supply place, and I give them all my business.
 

Wizard69

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The first thing that came to mind is that you need to be careful doing any casting indoors, even with the electric furnaces. The reality is you can have gases generated that are not good for you and as such any indoor casting needs significant ventilation. Just after leaving high school I spent 2 years working in a zinc die cast foundry and even in upstate NY during the winter we had the windows open and the fans running. The furnaces where natural gas but it wasn't the fumes from them that was a big concern, it was everything else in the air.

So given that you need ventilation I'm not sure an electric furnace will be a big win. Even so there are good reasons to go this route and you best bet is to look up the DIY solutions out there. By the way there are more than one approach here for electric casting, induction furnaces are a possibility if you are up to doing the electronics to make it possible.

Commercial systems can be had from companies like: Small Induction Furnace for Iron/Steel/Copper/Brass/Titanum/Gold/Silver. Yes a few bucks more due to the control systems but for indoor usage it might be the right path to follow. In any event I just wanted to highlight the number of options that can be had and still be "electric"
 

Willyb

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Don't waste your time melting Cans as you can see by "swst" video all you end up with is junk.

Cheers
Willy
 

Willyb

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Making Electric Aluminum Foundry DIY by the broken electric stove
👇👇👇
Excellent job building your electric melting furnace. What did the soft fire bricks end up costing you? I know they are considerly more over the hard fire bricks.

Cheers
Willy
 

Rational Root

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Unless you are using perfectly clean aluminium ingots, you will have some pretty nasty fumes. Aluminium wheels have lacquer finishes, and usually lots of oil and other gunk.
At minimum I'd want a garage door open for ventilation, and a big fan blowing the smoke out.
Zinc carries further problems, as it can easily boil, and you end up with zinc oxide fumes.
And finally, spilling a large crucible of aluminium indoors might ruin your entire day...
 

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