Tell me about this kiln please

R

Randydb

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Sep 27, 2014
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This kiln is for sale locally. Looks like it heats to 2350 degrees.

I have to admit I know absolutely nothing about heat treating. I have sent my work out for HT so far. I just see the digital controller on it and wonder if this would be a good buy.

IKiln / Furnace $ 399.00 OBO
Inside Dim 18" x 18" x 18"
5500 Watt 208 volt 3 Phase

My questions. I have 220v single phase in my garage...this being 3 phase...I know that it is close to impossible to get 3 phase into my residence. I do have a vfd that converts to 3 phase, but that is for controlling motors.

If I can get around the 3 phase part, would this be a good deal on a kiln for knife making? Is the digital controller allow me to set things up to do ht and just set them off to run?
kiln stats.jpg controllerkiln.jpg kilnpic.jpg
 
Several things:
1) It is a pottery kiln. They are not really right for knife HT. It will work, but not optimally. You will have to re-configure the top to allow blades to be hung inside the chamber.
2) It is 3 phase. While a VFD of suitable wattage would run it, the total cost of kiln and controller would be nearly what a new knife kiln costs.
3) It is a resistance device. If you are handy with electricity and such, you could rewire it to run on 220VAC single phase . It wouldn't be hard to do if you fully understand wiring circuits.

I would only offer $200 for it and then re-wire it.
 
My $0.02, I HT vertically and love it. I use kanthal wire and make pieces several inches long with a small hook on one end and a closed loop on the other. I have several of these wires premade. Then I have a nonconductive plastic rods with a hook that a wire hangs off of. I close the top opening with some broken scrap pieces of soft brick I had, and when it comes time to quench you just lift a rod up and the steel out of the oven and then straight into the quench tank. Hanging vertically helps heat the steel evenly and reduces warping, and no fumbling around with a door open trying to grab a blade with long pliers.
 
[QUOTE="Stacy E. Apelt - Bladesmith, post: 19354420, member: 134698"

2) It is 3 phase. While a VFD of suitable wattage would run it, the total cost of kiln and controller would be nearly what a new knife kiln costs.
3) It is a resistance device. If you are handy with electricity and such, you could rewire it to run on 220VAC single phase . It wouldn't be hard to do if you fully understand wiring circuits.

I would only offer $200 for it and then re-wire it.[/QUOTE]
Couple questions more....I own a vfd already and use it to run a 2 hp motor on my belt grinder. I am guessing it might not be a vfd of sufficient wattage. I will have to look. But how much is a single phase kiln with digital control worth? When I look on Canadian Knifemaker the are around $2800.

My son in law is a journeyman electrician. I would expect he would be able to rewire it to single phase. I saw a couple sites talking about rewiring to single phase. My question here is how do you know it is a resistance device and is the easier type to rewire?

Thanks
 
All electric ovens heat using resistance. Only other way to heat with electricity is arc and induction and both thoes are way out of the league of home shop stuff. Then again I am looking at trying to cobble togather an arc furnace and using my 400 amp welder as the power supply lol. Sorry off topic. But yeah it’s resistance, the coils around the inside heat up because of the resistance. You would have to look at the wiring inside the controller and figure out which ones are the elements and then use an ohm meter to see where your sitting at for resistance. Then require the 3 phase elamants to single phase. The digital controller part could be simple or a pain. It could just be running off 2 legs of the 3ph or it could be wired to 3 wires. But if you look at the picture it’s plugged into a regular outlet so it’s possible and quite common that the control side runs of standard 120v. Most of the guts of controllers run off a DC source anyway.

if it was close to me and I could get it for cheep I would buy it but I have doing a good bit of wiring of this type of things.

Oh and that oven is going to take a good long time to heat up to temp at that wattage. My oven is 5.5x5x31.5=866 cubic inches and it’s 4000w which is 4.6 watts per cubic inch. It takes about 40-45 min to hit 1900-2000°. This oven is 18x18x18=5832 cubic inches and at 5500w that’s .943 watts per cubic inch. I’m guessing to hit the upper temps if 1900° it would be an all day affair.
 
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What JT said.

The re-wiring is just a basic reconfiguring and all you really need to do is figure what size breaker you need at the wall box. The controller runs on single phase almost surely and will require little or no rewiring.

The biggest issue it the large chamber volume, which is just a matter of heat up time and cost to run.

You can cut five or six 2.5" holes in the center of lid and cover each of them with a 4X4"piece of Ins-wool and a firebrick. As Randy said, there are advantages to vertical HT.

None of these are deal breakers and the kiln will be fine once reworked.

I stand by my $200 valuation. I doubt people will be beating his door down for a 3 phase kiln.
 
Lucky you ! If you notice its nameplate. states 208-240V.
Running on 240V, it will be get hotter faster than 208V.
Notice also it has 6 heating coils. Easy to reconfigure to singlephase.
You may have to increase size of its line cord, and fit a NEMA 14 connector of suitable ampacity.
Your Journeyman Electrician should have no problem to reconfigure and verify your singlephase circuit is large enough.
 
Okay, much more reading later... first up, if I buy a proper ht kiln with a digital controller I am looking at how much $$

I read this at another site... "If your 3-phase system is Delta, which means there is no neutral, you can probably use the same elements. If your system is Y, which means there is a neutral, you will need new elements." https://www.paragonweb.com/FAQ2.cfm?FID=326

How do I tell if this kiln has a neutral or not?
 
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