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I'm trying to put together an electric foundry, with the goal of melting hotter temperature materials such as iron, so aiming for about 1600 degrees celsius. My main issue is finding a thermocouple that can handle it. It seems like I need to be looking for a B type thermocouple.

 

I also of course need heating elements, it seems like my only option is Molybdenum disilicate, but I haven't been able to find a source for this.

 

I haven't found a nearby source of bricks, the lower temperature ones are pretty common, but it's not my main concern as they are at least something I can find elsewhere.

 

If anyone can point me in the right direction I would be very grateful. It also occurs to me that a graphite crucible may leach carbon into my metals at those temperatures. Any crucible suggestions to solve that? Thanks!

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Casting iron is extremely dangerous and not recommended without proper instruction and safety equipment.  Based on the questions you are asking, I don't feel that you are prepared for this kind of equipment construction or casting effort.  I strongly suggest you find an instructor who can work you through this process.  We don't want your online name to reflect your condition.  Why do you want to cast iron?

Moly or silicon carbide elements and the hardware to correctly power them can be located in the electric glass furnace field, where they have grown in popularity in the last decade or so.  I've only seen them recommended for temperatures up to around 2,500 deg. F, so not sure if they will work for you.

For bricks that will withstand this kind of temperature, and hold up, you will likely need to divert into expensive high alumina bricks used for foundries and glass furnace lining.  You won't find them at your local hardware store.  Contact industrial refractory companies and consider castable products.  As far as I know, folks who smelt steel use the foundry shell as a consumable and don't expect it to hold up for multiple smelts, but that is a different process.

Type R or S thermocouples are the ones that I've seen for that temperature range.  Both the elements and the associated wire are quite expensive.  I"m not familiar with Type B, but they look similar from the Omega site.  Personally I think the thermocouple is the very least of your worries for this ill advised project.

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I'm looking at iron longer term, and intend to work with mainly bronze and copper initially. I am also seeking out some instruction locally, though it isn't easy to find. I have a strong interest in blacksmithing in general, and a strong desire to melt down metals and turn them into things. Be they useful, or just artwork, etc. I'm also an avid LARPer, and we can make use of a plethora of iron items.

Yea, I can find 2300-2500 F stuff reasonably easy, which would at least get me as far as the lighter metals. It may be the eventual route I take short term. I am not looking at hardware stores for anything, I've been checking with brick yards and such, unfortunately the more industrial places I have found them have had untenable minimum orders (hundreds or more pieces). High alumina and cordundum-mullite bricks, and a few others fit the needs, it's not a matter of not knowing what I'm looking for so much as sourcing them.

For steel it's really more of a question of whether I'm making steel, or just melting and reforming existing steel. Makes a big difference on how consumable my interior will be. If I can do the temperatures needed for iron, I can do steel if it comes up. It is not my focus.

Type R or S? I'll look into that, the ones I had seen were Type B, but they were either prohibitively expensive, or simply not accessible (MoQs again). The thermocouple is important for controlling the temperature, and keeping it stable. I obviously don't want to run things too hot and damage the coils or the furnace itself.

Maybe I can assuage a bit of your concern with the knowledge that I've spent quite a large number of hours over the past couple of years reading literature on smelting, foundries, forging, and so forth. Also I'm a scientist by trade, safety equipment is the very first consideration in everything.

 

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Apologies if I misunderstood you level of understanding of the process.  We get a lot of kids on here who saw the Conan movie and think that casting steel is the most direct path to making swords.

Again, I strongly suggest that you take some direct instruction with a group that is doing casting.  Not sure where you are located, but my local engineering school has an art class that casts iron.  You may need to travel to get instruction.  Even jewelry casting of non-ferrous metals should help.  Much better than getting maimed (no joke at all there).

From all I've heard, bronze casting is a much easier and safer path, and aluminum even easier.  I'm not sure why you feel you need to have extremely critical temperature control.  I think most non-ferrous casters just heat to liquid, rake the slag off and cast, but I'm no expert.  I also think most hobby grade casters use gas fired foundries.

Making steel is a major undertaking.  See if you can attend a smelt with an experienced steel maker (Lee Saunders, Tim Zoada...).  This will shorten your experimentation period quite a bit.  I don't know what kind of a scientist you are, but casting steel, in particular, is a very dangerous task.  I've cast molten glass at 2,100 deg. F quite a bit and would not even consider casting steel.  The smelters don't cast steel, they heat iron bearing ores and sands with charcoal and flux, then conglomerate and forge the resulting bloom.  Believe me that is plenty of work and will give you quite a sense of accomplishment (and it is much safer than casting steel).

While making steel is a wonderful goal, if all you want to do is produce handmade custom steel items you may wish to consider learning how to blacksmith.  After all it was a very rare smith that also made his own steel.

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I have never heard of a foundry using resistance coils for melting ferrous metals.  All the ferrous foundries I have been in use either induction, or arc furnaces or they use a cupola.

Smelko foundry products in Milton will have thermocouples crucibles greensand or Petrobond. But keep in mind the thermocouples that they have are designed for industrial foundries and will be very robust but not cheap.  They may be able to help you find a place in Canada that has a metal casting course as I do know that they have sold to several schools.  I hesitate to mention them as I hope people don't waste a bunch of their time. They are great guys there and they are running a business catering mostly to commercial foundries. They are very willing to help out and sell small quantities to individuals but they make there living selling industrial quantities of supplies.

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On 11/10/2017 at 4:51 PM, Latticino said:

Apologies if I misunderstood you level of understanding of the process.  We get a lot of kids on here who saw the Conan movie and think that casting steel is the most direct path to making swords. custom steel items you may wish to consider learning how to blacksmith.  After all it was a very rare smith that also made his own steel.

No need for apologies. I appreciate the genuine concern and help. I haven't seen the new Conan movie, I have a feeling I would be quite disappointed as a fan of the original.

I'm definitely working on connecting with nearby groups as much as I can. I am also intending to learn both blacksmithing and casting (of a variety of metals). Bronze and aluminium are my intended starting points, I'm intending to try to build robust things as I go that I can replicate when they fail or need reworking that can handle a variety of tasks. Since we're talking low quantities I feel that electrical is the cleanest and best route, and should be capable of everything I need.

Bloomery work is something I'm quite interested in, and does sound very interesting. I only have seen one place that teaches that in Ontario, a blacksmith, and it's unfortunately not a possibility for me at hte moment.

The other difficulty is finding an anvil that doesn't break the bank, or even a stand in object like a rail chunk. I've had little success sourcing anything thus far.

 

21 hours ago, JNewman said:

I have never heard of a foundry using resistance coils for melting ferrous metals.  All the ferrous foundries I have been in use either induction, or arc furnaces or they use a cupola.

I haven't either myself, but it doesn't mean it's not possible. I imagine for large quantities it simply isn't practical commercially. Arc furnaces are an interest, but quite dangerous and something I probably will look more into much further down the road.

I won't contact them unless I'm sure I can avoid wasting their time, I really appreciate the information.

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Welcome aboard Grimm guy, glad to have you. If you'll put your general location in the header you might be surprised how many of the gang live within visiting distance.

We get a little jumpy when a newcomer introduces him/er self by asking questions like your's. We tend to prefer to er on the side of caution. Check out the recent "easy burner build" thread for a good example of enough knowledge to be dangerous. 

I don't know what kind of wattage a resistance melter would require for even small quantities of iron, say 1-2 lbs. I think you'll get much farther for a LOT less $ with an induction forge. The economy model will melt a couple inches of 1" sq. mild steel bar in something like 45 seconds.

Frosty The Lucky.

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19 hours ago, Grimm Spector said:

The other difficulty is finding an anvil that doesn't break the bank, or even a stand in object like a rail chunk. I've had little success sourcing anything thus far.

Check out the Collection of Improvised Anvils thread for some low-cost ideas. 

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i'm a little late to this ..sorry if its a necropost

you can check ebay stores for some high temp elements ...  they usta have the moly  ( they also have some high temp kilns from china .. which i've seen other use it for melting steel on other forums )

not sure on the ifb's that'll handle that kinda temp...   your on your own with that as in my case, i'd only consider much more durable materials

it'll be lot's cheeper to make a propane melting furnace to melt an iron charge ...  myself, i get my refractory from vesuvius

don't worry about the uptake of carbon from the clay graphite ... it will happen, but your low carb iron will take awhile at liquid temp to pull it in 

? why not cast in cast iron ..    melt temp is way lower and much easier to reach !

 

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