Should I bother with this kiln?

S

Sandeggo

Joined
Nov 17, 2014
Messages
254
A friend of a friend has an old top load paragon that he says is 3 phase. He also says it's about 2 cubic feet inside. I haven't checked it out in person, but he texted a pic of it. The price is free but I don't want to go a grab it if it's not gonna work for knives. Being 3 phase can it be ran off a vfd? If it will work, what should I look for when I go get it?
D4BF11AB-756A-4A82-8ECB-B6E77FE5AE2C_zpskgt418lf.jpg
 
VFDs are designed to run motors, you'd want to use a rotary phase converter to generate 3PH power.

For free, take it and use it till you get a 'proper' knife kiln. it wont be as easy to load or unload, but it's still usable, and the price is right.
 
Justin.Mercier said:
VFDs are designed to run motors, you'd want to use a rotary phase converter to generate 3PH power.

For free, take it and use it till you get a 'proper' knife kiln. it wont be as easy to load or unload, but it's still usable, and the price is right.
Click to expand...

Yeah if in fact it is 3 phase that will kind of kill it. I'm definitely not gonna drop the coin on a rotary phase converter. I'd rather save the money for a real heat treat oven.
 
For free ?

Take it

Three phase power in, but I bet the controller is not three phase

It will have three channels of control like a three pole contactor and three heating elements



You can just use two heating elements ans stop using one line


This could be a very cheap conversion for you.
Maybe even no cost at all



take it home, clean it, take nice photos and show us what you got.
 
I agree with the count. And if it doesn't work for you, then at least you'll have a bunch of insulated bricks to make your own kiln.
 
I agree with the count (Alexander literally took the words out of my mouth), take it! With a bit of work I would bet it can be used on single phase. Like the count said if there is a controller its unlikely to be 3 phase.

I had a gentlemen give me an old pottery kiln about a year ago. I bought a cheap PID temperature controller off ebay (mypin brand) and have a pretty decent heat treat oven for only about $60(PID, SSR, thermocouple, and some wire). Its a top load like the one in your picture. As was already stated it's a bit annoying to load and unload, but for how little I had to investment it has worked great. I'm no expert but if you do go that route and have any questions I'd be happy to help anyway I can.
 
Three phase on motors is a big deal. Three phase on resistive elements is not. Would you have a problem with a 3 phase light bulb?...No! it just heats up between two phases.

Take a look at the wiring, and if possible get a schematic from the maker. It should be easy to convert to 220/240VAC single phase.

Some ideas for such a free kiln are:
Vertical HT kiln.
Low temp salt pot for marquenching and nitre bluing. (simple and safe)
High temp salt pot for austenitizing. ( Caution dangerous - only if you fully understand this subject)
Tempering oven
Really col looking trash can for the shop :)
 
Sandeggo, having seen your other DIY projects I've got no doubt you can make this work.

I'd want to figure out if it can be used horizontally. It just seems more natural than lifting things in and out of it.
 
I'll have more specifics in the next few days. I did find out that it's an old paragon. I'm planning to go look at it hopefully thursday
 
It's a paragon a88b single phase 230 kiln. Came with a bunch of cones and even the manual. It doesn't look like it was used much if at all. It's just gigantic 18" tall, 18" wide. I can't imagine what my meter is going to do when I flip the switch on this.
.
40329873-B01E-4789-9C49-A29CE6E408CD_zpsbmpuxvg0.jpg
3ECE8DDA-AF2F-48C7-9158-7221C42E5A6A_zpsxj8wi8nx.jpg

I don't know what that plug is for.
97BA369C-357A-493C-ADE7-5A8B06326F00_zpsfaawz2oh.jpg

668303A0-4DCB-4169-ABEE-EF8FD40410C9_zpstiso5ie0.jpg

470AED67-6953-4C46-A30E-AC9DA0FC3FA9_zpsvg2vb2qy.jpg
 
What a score, and for free! You're going to need some sort of platform in there to set blades on so you're not reaching your whole arm into that beast.

Sandeggo said:
I can't imagine what my meter is going to do when I flip the switch on this.
Click to expand...

Until it reaches temperature it's going to draw something like 25 amps :) but I would bet it gets up to temperature in 10 minutes. My oven is smaller but at temperature runs at like a 5% duty cycle.

Sandeggo said:
I don't know what that plug is for.
Click to expand...

NEMA 14-60 I think. I assume that's for pluggable receptacle instead of direct wiring. But I know nothing about kilns.
 
zhyla said:
What a score, and for free! You're going to need some sort of platform in there to set blades on so you're not reaching your whole arm into that beast.



Until it reaches temperature it's going to draw something like 25 amps :) but I would bet it gets up to temperature in 10 minutes. My oven is smaller but at temperature runs at like a 5% duty cycle.



NEMA 14-60 I think. I assume that's for pluggable receptacle instead of direct wiring. But I know nothing about kilns.
Click to expand...

Just read through all 46 pages of the manual online. It's a 4 element kiln. I need to get a digital control unit and then fab up a rolling base for it. That way I can wheel it around the outside of my garage to get close to my 220 plug and still have the kiln outside. I don't want to use it in the garage as there's a sprinkler system in it because I'm in a high fire zone.
 
I have mine on a wheeled wire rack cart so I can do just that. The actual oven is pretty harmless but quenching can smoke and/or catch fire.

What's the control interface? Relays? Is there a thermocouple in it already? I've had good luck with the $30 Chinese PID controllers, shouldn't be hard to rig up one of those to control this.

It may be worth rewiring so only half the elements activate, that just seems like a lot of wattage. Too much power and it will be harder to stabilize.
 
Single phase and 26 amp draw 240VAC. You really need a 40 amp circuit wired in 8 gauge copper wire for that baby to run on. A 30 amp circuit would work, but is getting close to the max draw. I would only use 8 gauge copper because the draw time is long and steady.

What you need to do to make the kiln useful for HT of knives is modify the top so you can hang the blades in the kiln. You DON'T want to open that up while hot. Repeat - DO NOT OPEN A TOP LOADER WHILE HOT!!!

Cut some holes in the top and put firebricks or a sheet of kaowool over them when in use. To hang the blades, make 1/8" stainless rod hangers in an "L" shape ( 12"X6") with a wooden handle on the end of the long leg and a hook on the end of the short leg. Hang the blade from this and set in a hole. Place a fire brick over it. Pick up with the wooden handle when removing the blade and lower in the quench tank on the hook.
Another method is to make "T" shape hangers and lift them with tongs.

A PID and a 50 amp SSR will run that kiln. Get a good heat sink and a fan for the SSR. Use an 8 gauge type K TC. The sticky on a toaster oven conversion is basically the same as this conversion. Just make the controller, wire the power cord from the kiln into it, and set all the kiln controls on HIGH.
 
Stacy E. Apelt - Bladesmith said:
Single phase and 26 amp draw 240VAC. You really need a 40 amp circuit wired in 8 gauge copper wire for that baby to run on. A 30 amp circuit would work, but is getting close to the max draw. I would only use 8 gauge copper because the draw time is long and steady.

What you need to do to make the kiln useful for HT of knives is modify the top so you can hang the blades in the kiln. You DON'T want to open that up while hot. Repeat - DO NOT OPEN A TOP LOADER WHILE HOT!!!

A PID and a 50 amp SSR will run that kiln. Get a good heat sink and a fan for the SSR. Use an 8 gauge type K TC. The sticky on a toaster oven conversion is basically the same as this conversion. Just make the controller, wire the power cord from the kiln into it, and set all the kiln controls on HIGH.
Click to expand...

Would the amp draw be the same if I was only using 2 of the elements? Since this thing is so large, I think I'm going to get some kiln bricks and stack them in the bottom to essentially cut the volume in half. Then I could just use the top 2 elements. Besides that, I don't see why I couldn't fab up a stand and door hinge to use this on it's side. If that is not recommended please tell me. I found a local ceramic supply that has kiln bricks in stock for $5 a piece. I'll read the toaster oven sticky, thanks
 
zhyla said:
I have mine on a wheeled wire rack cart so I can do just that. The actual oven is pretty harmless but quenching can smoke and/or catch fire.

What's the control interface? Relays? Is there a thermocouple in it already? I've had good luck with the $30 Chinese PID controllers, shouldn't be hard to rig up one of those to control this.

It may be worth rewiring so only half the elements activate, that just seems like a lot of wattage. Too much power and it will be harder to stabilize.
Click to expand...

The control is a timer and this deal they call a kiln sitter. Basically it's a lever that triggers a mechanical switch. You place a cone inside holding the lever up and when the cone bends it shuts the breaker off. I can control the 4 elements with the 2 knobs. 2 elements per knob, top and bottom independently. So yes you can just use 2 elements. There is not a thermocoupler
 
Stacy E. Apelt - Bladesmith said:
...What you need to do to make the kiln useful for HT of knives is modify the top so you can hang the blades in the kiln. You DON'T want to open that up while hot. Repeat - DO NOT OPEN A TOP LOADER WHILE HOT!!!...
Click to expand...

Stacy, why is it you don't want to open top loading kiln while hot? I mean obviously its hot and heat rises so you need to watch out for that, but is it bad for the kiln as well? The reason I ask is I've been doing that for the last 6 months :eek:...you've not steered me wrong in the past so I'm thinking I should probably look at modifying the top.
 
You must log in or register to reply here.
Back
Top