Making an Electric Casting Furnace: Part 2

[@taow]

Been looking forward to this one for a while, Inspirational build and I really like the glass rod idea, it'll be interesting to see how well it holds up

[@ChrisDePrisco]

Still going strong after dozens of heating/cooling cycles up to 2000F. I'd say it's safe to give it a shot! :)

[@r.j.sworkshop7883]

Watching this one closely. Electric is the way to go, and with 6.2 kW of solar powering everything that I have, it is much, much cheaper than any other power source. Thanks for posting I look forward to #3. R.J.

[@ilyashoshana3950]

Man you like to make everything in hard way . My respect to you man.

[@Stephen1455]

I'm impressed you know machining and electrical, as a machinist I never conquered my fear of electrical!

[@ChrisDePrisco]

I started off with electrical stuff as a kid (low voltage DC stuff obviously) and went from there. The machining is relatively recent. :)

[@76Richie19]

awesome build, this old Tony has a video about springs where he's using the thread cutting on his lathe to make equally spaced springs. so you wouldn't have to stretch out the coil by hand. but still an awesome build - keep up the good work.

[@peterbornmann9184]

I found this, and it is 5 years old. Its nice. But is there a part three?

[@R3d46]

Fantastic video and even more interesting to see we've got the same last name. I am Italian and that last name is rare enough to see here, usually common only in a very specific area of southern Italy, so seeing it on here was definitely a surprise!

[@ChrisDePrisco]

R3d46 That's awesome, hi! :)

[@EarthlyF0rg0ten]

Love your work! Keep it up always subscribed!

[@JulianMakes]

great video! was that Celsius or farenheight? thanks

[@raymondflowers2167]

Back when I was a kid one of the things at carnivals was stretched Coke bottles. Basically the same thing you have with no bottom. Raise it off the table, tie a soda bottle neck so the body is in the kiln, turn it on, and as the glass heats up, the bottle stretches out to whatever length you want it to. Do a GIS for stretched out soda bottles

[@ChrisDePrisco]

Haha I've heard of those but never thought about how they did it!

[@gnawzie]

is it safe to handle ceramic wool with no protection???

[@filopat67]

Nice build, what is the diameter of that kanthal wire and from where did you buy it? I would have put those coils to lower two slots instead, heat rises up and all that you know, don't know if that's with any significance in this case though. Keep up the good work!

[@ChrisDePrisco]

It's 16 gauge which is the biggest I could find, easily. I got it on Amazon. Yea I don't know if it matters where the coils are. Everything I've done with it has been in the top half anyway.

[@arnljotseem8794]

Nice build. Why did you put the glass tubes in the coils? Are they not stiff enough to avoid collapse? I just built a small heat treating oven, using 1x0.3mm Kanthal wire at 3.9 ohms per meter (1.3 ohms per foot). So far I have tested it at 1560 degrees F (850C) and no need for any rods to hold the coils together. Although I did have som trouble with the coils twisting out of the slits when heated. Fastened them with some steel pins to the blocks. My goal is to heat treat a special tool steel at 1920F (1050C). Hope to put out a video soon (but my graphics car said bye bye).

[@ChrisDePrisco]

Correct. I heat to about 2,000F occasionally which was enough to completely collapse the Kanthal wire of about the same gauge in my last kiln. The staples work well enough in the ceramic fiber board but they have no grip in the bricks like I used; they just pull right back out. So, I figured I'd try and find something that would support them. So far the glass is still perfect after about 30 cycles!

[@danvandertorre9280]

what is that readout meter and were can I get one .thanks good job

[@PrivateNexus36]

What gauge is your kanthal wire?

[@MegaChekov]

she did glow very well done

[@pcngamingkolaka9184]

what the name of the electric component?

[@Yuuki1942]

nice job.wish to see some melting next time.whats the highest youve gone up temp.?

[@ChrisDePrisco]

Soon! About 2,200F so far; at 2500F the coils melt.

[@prostipirugolfo4611]

what resistance measure did you use

[@slicktires2011]

Nice build! What gauge Kanthal did you use? I'm planning to build one and run on 120 VAC, with around 1800 watts I need about 8 ohms coil. It seems to me my coil would be very short, so I can't wrap multiple turns on the furnace. Your coil seems longer, so I wonder what gauge you use.

[@tamacoable]

In one of his comments, he mentions his runs roughly 3000w, and at 220v must be pulling 13.6A (P/V=I). And so his element must be just over 16ohms (V/I=R). From your figures, you're running 120V @ 15A. I think AWG 18 kanthal runs at 1.7 ohm/meter, and he used a whole spool, so maybe a 10 meter spool? So my guess is, he used AWG18. So like you said, your coils going to be very short or very thick!

[@tamacoable]

Actually scratch that, further down he says he uses AWG16 wire, so he'd be using roughly 15 meters.

[@gomalarga]

awesome work! is there any detailed guide in your patreon?

[@Chen-zd6rx]

1750 degree c ? Why the heating wire is not blown ?

[@danielazbell2412]

Hey, any chance we could get a BOM or those plans you refrence in the first video? Thanks!

[@ChrisDePrisco]

+Da Az I'll see about the plans if I still have them. Remind me in a day or two if you don't hear back. The BOM changes based on a lot with what you can find, the wire, thickness, number of turns, etc. There are good resources online though. Kanthal 16 gauge, PID temp module, a high temp thermistor/thermocouple compatable with your PID, high current AC relay for the PID to switch the 220 or 110v AC and then just some fire brick and quartz glass tube. Has to be quartz or it will melt.

[@danielazbell2412]

Thanks! Really I was wondering if you needed a special PID to handle the high voltage but then I realized with a derp that that was what the relay is for. Would thinner kanthal yield a more resistive coil that might work on 110v here in the us? My 220v isnt in a convenient spot for smelting.

[@ChrisDePrisco]

Sure. You'd have to do the math but basically the lower voltage makes it harder to get high temperatures - at least quickly.

[@Cornpop1234]

Did your glass tubes melt?

[@ChrisDePrisco]

They did not! No cracking, no deformation or anything over a couple dozen firings of up to 2,200F. I'm super pleased with them.

[@lelearmi6186]

Hi cris congratulations for the video. I ask you: with this the resistance lasts a lot? Can you use it for a long time?

[@ChrisDePrisco]

+Lele Armi It doesn't last forever but it should be good for at least several dozen hours, if not 100+ hours.

[@lelearmi6186]

Thank you for the reply . The resistance is in kanthal? 100 hours are few, so is a machine for just the right experiment? In my opinion, with few modifications, it can be very lasting and put in a working environment. what do you think about it ?

[@ChrisDePrisco]

+Lele Armi How long it will last depends on a lot of things, the diameter of the wire, the operating temperature, how many on/off cycles, etc. There are thicker elements made of things like silicon carbide if you want it to last even longer.

[@evilcanofdrpepper]

Heat rises, I feel like you should have put the coils in the bottom 2 slots in the bricks. I wonder if it would have made much if any of a difference..

[@Moronicsmurf]

Where did u get your kanthal thread, what wire dimension is it, and how did u calculate the coils? I have only used premade ones.. But this got me curious in doing a second attempt at a electric kiln instead of my oil burning ones.

[@ChrisDePrisco]

I got it from Amazon, from a company called Temco. It's 16 gauge. For the length calculation I used their ohm/ft spec and deepfriedneon.com/tesla_f_calchelix.html for a calculator. Know the resistance you want, coil diameter and spacing and just keep changing number of turns until it calculates the length you are after.

[@jacewalton6677]

how many watts is the furnace?

[@ChrisDePrisco]

A bit over 3,000 watts

[@MichaelTeeuw]

Doing 220v electronics work on a metal desk. I see that you like to live dangerously. 😁

[@flashpointrecycling]

Chris, what is the diameter of the Kanthal wire and how many feet do you have in the kiln? Did you calculate from the resistance of the wire to determine the feet you need and amperage available? Or, did you find a plan out there somewhere? Love your show! Can't wait to see more on the mill!

[@ChrisDePrisco]

+Green Range it's 16ga which is the biggest they sell on Amazon. I did the calculation based on this into www.euclids.com/Html%20pages/element-design.htm and used a coil length calculator to get the final length. I don't recall that I actually used though.

[@hkkhgffh3613]

1750 deg c! Crazy man!

[@VojislavDjuric79]

Nice job is that 1750 celsius of fahrenheit and if i got it right you got all that heat from 1,21 kw ?

[@ChrisDePrisco]

That's in Fahrenheit. It's actually right about 3kW (~15 ohms at 220VAC) but I really wanted to use that joke.

[@VojislavDjuric79]

Well then better make torch on propane gas or you will get high bills for electricity...well if you planing to melt only aluminium with this furnace you can do it in 30-35 min so actually not bad...

[@joshua43214]

Electric furnaces are way cheaper than propane. This little thing will cost under $0.40 an hour to run. Even factoring in replacing the coils (he has a ton of shorted coils and sharp bends), it is still way cheaper than propane. It scales nicely too. A furnace that will handle a #16 crucible will also be far cheaper than propane, and you will get a better melt. Down side is the system is less flexible than a gas/oil fired job, and more complex to design and build.

[@ChrisDePrisco]

I pay $0.11/kWh so it's like $0.35/hour to run. :)

[@ChrisDePrisco]

There are no shorted coils; although it may look that way. Some are close but I made sure none were touching. It's already lasted longer than my purchased furnace, although that one used a slightly smaller gauge wire. I'm probably at about 20 hours so far, mostly at 1,750F. I have no idea how long they will last.

[@brianknickerbocker8518]

Very cool, Would love to build one, but there's that dumb ole money issue.

[@randomstranger9674]

Surprised you put the heating coils at the top, especially given the temp sender is at the bottom.

[@ChrisDePrisco]

The thermocouple is about in the middle but the primary use for this is melting metals in a crucible which hangs from the top, down to just a bit over 2/3rds of the height. I wanted the coils as close to the stuff it would be heating as possible.

[@WobblycogsUk]

Nice build, all that bare copper wire around the place makes me nervous though.

[@ChrisDePrisco]

+Wobblycogs Workshop That's all grounding wire for the exposed metal bits so its perfectly safe; or at least equally as safe as the metal. :)

[@mountainmanfab]

Nice! course now your gonna have to make a larger one...oven or kiln style...for heat treating/oven brazing etc etc :)...If you make it reasonably airtight or top opening you can even do things under an inert gas...lol gotta love tool fever! Remember too heat treatment of aluminum castings isnt rocket science either...just needs good temp and time control :)

[@ChrisDePrisco]

I know, right? I've actually been using it mostly for heat treating the S7 steel stamps I've been making for the silver casters. I got some stainless tool wrap for them and they come out extremely well compared to the flux and crap I was trying earlier.

[@mountainmanfab]

yeah covering them in borax works but a foil wrap with a bit of paper or cloth thrown in to use up the oxygen cuts way down on the cleanup

[@ChrisDePrisco]

That's an interesting idea!

[@eformance]

I call this soundtrack "Star Wars Cantina Music".

[@cylosgarage]

yay a new video!

[@Livefreeman]

I don't feel comfortable working with AC, can these coils heat up using DC power supply

[@k192447]

1750Centigrados, excelenttttttttttttttttttttttt.

[@Thefreakyfreek]

120 volts 😂 noting personal just the fact that 220 volt is special in the usa is funy

[@machinist7230]

Thefreakyfreek virtually every house in the US has 220v, its just that typical wall outlets are 120v, 15a. What happens is the power coming in is two different 110v "legs" come in, 180 degrees out of phase with each other, combined it makes 220v, for things like stoves, air conditioners, etc. Its known as 220 single phase. Industrial power is usually 220v 3 phase, which has 3 powered legs, 120 degrees out of phase with each other.

[@faxezu]

For example every normal building in Germany have a 220V 3 phase house connection which is used in the stove. Furthermore it is split to three normal 220V rails who power the normal outlets.

[@taylorcanty5890]

Thefreakyfreek Over here in New Zealand, we have 240v wall outlets

[@mungbeans9]

And a juicy 400v on 3 phase

[@neonboy22]

its 230 in NZ. 240 in Oz

[@andersmeiniche2746]

Marty are you back from the future 😂

[@TheFlyre]

wow that wont melt tungsten

[@k192447]

very gooddddddddddddddddddddddddddddddd.