Starting my first and only electric foundry build

Discussion in 'Furnaces and their construction' started by DIY Builds, Feb 22, 2018.

  1. DIY Builds

    DIY Builds Copper

    I was thinking I would use a old hot water heater I have in my basement for pouring the casting refractor in? That should work pretty good and prob about the size I was thinking of
     
    DavidF likes this.
  2. DIY Builds

    DIY Builds Copper

    How heavy of Kanthal wire should I get? Is 14ga to big or is 16ga heavy enough ? I see in the one video he uses 14 I guess so prob answered my own question
     
    Last edited: Feb 23, 2018
  3. Jason

    Jason Gold

    14 is actually larger than 16. In wire, the smaller the number the bigger the wire. My kiln has 14ga in it. How are your electrical skills? You'll need to sort out resistance, length of coils, amp draw ect. AND you have to run it on 220vt and that can be lethal. Proceed with caution.
     
  4. DIY Builds

    DIY Builds Copper

    Yea I had a brain fart shen I was typing wire size. As far as the electrical part of it I don’t know how to do the amp draw and figure out the length I guess. As far as hooking up 220 I’m not worried about that. I’ve hooked up lots of 220 and even 480. Put new sub panels in but as far as figuring out how much resistance or amp draw I need I will say I do not know how to figure that out and was hoping someone could help with that.
     
    Last edited: Feb 23, 2018
  5. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    DIY, you've mentioned that you want to melt cylinder heads but I don't recall you indicating what you actually want to make.

    While I do use electric, it can be easily converted to fuel and I have a larger furnace as well which is primarily fuel fired with electric capability. My smaller furnace is just the opposite.....primarily electric and fuel fired capable. There are pros/cons to each but it depends upon what you want to do. For me, I wanted to make automotive and machine parts, 90%+ of which were either fine or best in aluminum. I also wanted to have a go at investment and shell casting. A PiD controlled electric not only could melt but also heat treat castings, perform investment and shell mold burn outs, and heat treat tool steel....all in essentially one machine. The latter tasks have long temperature schedules and an electric can be left alone and inside for these tasks over hours or days. I couldn't control temperature sufficiently nor would I leave it unaccompanied during those tasks. Electrics tend to be a little slower to melt compared to fuel fired furnaces but in my case I see hardly any difference or benefit over 10 minutes difference in melt time but you don't have to replenish fuel and melts literally cost just a few pennies at the flip of a switch. I set myself up to have bronze/iron capability but neither scratches my itch at the moment. As the hobby goes, I'm not just passing through, I've taken up residence.

    For my build, I started with the weight of the biggest part I wanted to cast and added ~30% to that for sprue, gates and risers. That brought me to 50Lbs+ of aluminum. The first crucible I bought was an A60 and everybody gasped. The furnace and equipment to handle that task is not for the light hearted. I took advice from the casting community but even my small furnace can handle and A20 which is about ~25lbs which is much more than most hobby casters will ever do. I designed my furnaces around those crucibles. My furnaces have lift off bodies which makes them smaller than most furnaces to accommodate those crucibles because they don't have to accommodate lifting tools between the crucibles and furnace wall. A lift off furnace is a big complication to a furnace build. You can build a conventional lift out crucible furnace in a weekend or two. My electric is 8.5kw because that was the maximum energy density recommended for furnace that size with coiled heating elements.

    If your interested in higher melt point metals I'd discourage you from going the electric route. But if you fit my description in the first paragraph above, it may be right for you. Your going to invest time and energy into developing and controlling either a source of electric heat or a burner for fuel fired heat. Some of this decision also depends on what knowledge and skills you already posses. Machine design, fabrication are second nature to me and my shop is so equipped. That's not the case for everybody. I've been around castings and foundries but that's not the same as managing it all yourself. It also depends on how committed you are to entering the casting hobby. Which reminds me of one of my favorite jokes.

    So I ask, are you up for one or would you like to have a go at them all?

    Your probably thinking you'll build a furnace and be there, but your going to have to acquire mold making materials, flasks, lifting tongs, pouring shanks, maybe make some molding sand and possibly a muller to process it in order to cast parts. If all you want to do is melt some aluminum in a soup can and pour some ingots into a muffin tin so you can make a YouTube video, some charcoal, plaster, and sand in a bucket will do. Now if you're not just passing through and intend to stay for a while, you've got some research to do....otherwise you'll go through some iterations improving your equipment if your ok with that.

    There's help here for any and all of the above here. What sayeth you?

    Best,
    Kelly
     
  6. DIY Builds

    DIY Builds Copper

    Thanks kelly for all of that. All I want to do is melt some stuff right now. Maybe sell some lead or what not. I’m sure there’s no money in it but just thought it would be nice to have access to melting metal. Just something to add to my stuff. I would like to make some parts that I could turn in my lathe someday maybe but only have 1 project I started last year that I haven’t finished requiring machining. I’d like to make some 4” round stock out of steel since I don’t have a spool gun. I can always go to town and buy it though. Just thought with all the scrap laying around I could make my own just to say I did it. I mainly wanted to do electric because I can fine-tune the temperature and maintain the exact temperature I wanted. To be completely honest if I spent $150 on it I would be fine with that. I’m not looking to pour a pile of money into this right now
     
  7. DavidF

    DavidF Administrator Staff Member Banner Member

    Melting temp of steel?? Melting temp of the elements?? Huston we have a problem!!!
     
  8. Frank Clark

    Frank Clark Copper

    3C1BCD6E-3BC4-4DD9-BAA7-007730B7638C.jpeg My electric furnace draws 50A @ 230v. This takes 6ga wire. I did have to upgrade wire between my main panel and the sub that the 50a breaker went into. My house has 400A service. If you have 200A service you may have to consider what else in the House is running. If you have 100A service this may be a bad idea.

    I use ceramic mat heaters with kanthal wire. These are similar to those on heatandweld.com but are made in custom sizes/voltages for us at work.

    My furnace uses two 110v heaters in series and my kiln uses 1 240v heater. Both are capable of running to 1600f+. But I’m not wired to run them both flat out at the same time.
     
  9. Frank Clark

    Frank Clark Copper

    And No, you are not going to melt steel with an electric element furnace. I do have a customer that uses induction. But he draws 7MWs (that is 7 MILLION watts) when he fires that thing up. Induction heaters are great - but that is a science and would require significant education for a DIY implementation.
     
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  10. DIY Builds

    DIY Builds Copper

    Thank you for being that to my attention. I would have to see how big my panel is in the garage and house. Maybe my best bet would be to grab the bertha torch and use that for now. I just want something simple and low cost right now so I can see how it goes
     
  11. Jason

    Jason Gold

    You can do a lot with a HF weedburner running on propane. It all comes down to the duckets.
     
  12. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Honestly, I'd recommend you consider a conventional tangential Tuyere lift out furnace with a dense castable refractory hot face, a couple inches of insulating wool, and a Reil-type naturally aspirated propane burner, but as Jason said, a HF weed burner gets you a fair way there. You can do a lot with such a set up.

    As far as the budget, it depends upon the size of your furnace and whether you need one or two bags of refractory. Most people can't get there with one bag and if so probably puts you closer to $250. You can make a Reil burner for $10 worth of parts but you'll need a propane tank and a high pressure propane regulator.

    Ya-know, if all you want to do is melt some stuff, you could literally dig a small hole in the ground or an uninsulated steel bucket surrounded by dirt, filled with charcoal, force air with a hair drier, and melt aluminum in a steel crucible. That would be just the cost of brickets and some scrap you have layin around.

    Best,
    Kelly
     
  13. DIY Builds

    DIY Builds Copper

    You lost me at tangential Tuyere lift out furnace.
    If I went the propane route that’s exactly the burner I was going to make Reil type and I’m starting to tink that might be the best route. I don’t think I’ll be digging holes anytime soon where I live lol
     
  14. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    It's the most popular style of home foundry furnace.......because it's simple and effective. The Tuyere is the hole you insert the burner. Tangential means it inserts on the tangent of the furnace ID. Lift out means you must use tongs to lift the crucible out of the furnace. More mandatory reading for you.

    http://www.alloyavenue.com/vb/showthread.php?2469-Foundry-Tutorial-Book

    ...or straight to the glossary....ya-gotta learn the lingo man.:)

    http://www.alloyavenue.com/vb/showthread.php?2469-Foundry-Tutorial-Book&p=70018&viewfull=1#post70018

    Best,
    Kelly
     
  15. DIY Builds

    DIY Builds Copper

    Lol thanks!! It would’ve been a lot easier if they would’ve just called it a hole in the side where you put the burner. Then I would’ve known exactly what you were talking about
     
  16. Jason

    Jason Gold

    Tuyere... pronounced Twee-Air. Lesson complete for the day. ;)
     
  17. DIY Builds

    DIY Builds Copper

    Baahaha thanks
     
  18. _Jason

    _Jason Silver

    DIY Builds likes this.
  19. Jason

    Jason Gold

    That's a good book for 9bucks....I need to pick that up. Thanks!
     
  20. crazybillybob

    crazybillybob Silver Banner Member

    That's a good book to start with for an electric build. It shows you 2 sizes of furnace. You can take what you learn ad make one bigger. #1 rule Buy a crucible and build the furnace to fit. #2 rule buy a bigger crucible than you think you need starting off. You can always put less metal in then the crucible can hold but never more.
    Basic rule of thumb for USA electric service if you plug your dryer in it it's 220 30A (or gas but let's ignore that). Normal wall outlet is 15A. Build to one of those, unless you are trained and comfortable with electricity (plugging crap into the wall is not Training!!) This stuff can and will kill you and not stop to think about it!!
    Listen to Kelly! He's built one of the (if not "The") nicest Electric furnaces I've seen on the hobby scale. He's got some talent in pattern making too.... Plus he's great about sharing what he's learned and what he's doing. Read the foundry manual in the link he posted. It's the short version!! Many folks here will point you to the US Navy foundry manual for things. It's also great but it's a big read, most find the topic in it they need help and reference it. Also have a since of humor we are a jovial bunch and can sometimes go off on a tangent (ask Jason about his BP ;))

    Use all the proper PPE!!! (Personal Protective Equipment... it's not just the bedroom where you need to be safe!)....no Flip flops are not proper work boots, no matter what they are wearing on YouTube!

    CBB
     
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