Is this ok for a heat treat oven?

R

romanx

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Jun 7, 2007
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I've found this kiln available, but I don't know if it is of any use to me. I won't be making any swords, so although it is small inside it should be sufficient.

Here are the details:

EFCO, Mod.170,220Volts,1500 Watts,1100 DegreesC°(about 2000F). (I'm in Europe so 220 volts is fine for me).
The kiln measures 270mm wide x 320mm high x 280mm deep.
The chamber measures a great 230mm deep x 180mm wide x 85mm high

Firstly, is it ok to use a kiln as a heat treat over? It seems that some folks have done this. Is there anything else I should be concerned about?

Thanks.

Romanx
 
American 220V is not european 220V.
American is tri-phase, as it is the equivalent of european 380V European 220V is phase and neuter. Using a triphase is possible, but requires some adjustment in wiring.
 
A kiln should be fine for you, as long as your steel doesn't require temperatures above your oven's capability. Some 220 here is three-phase, but a kiln is most likely single-phase.
 
Thanks for the replies. I might have been unclear - it is European 220v. I was just giving the 110v as the US equivalent as most guys on here are American. I am not knowledgeable about wiring etc. (or anything else really);).

So I could use the kiln. That's great. There aren't many steels that require over 2000F are there? I think S90V and some supersteel and maybe BG42, but stuff like O1, 154, D2 and S30v should be fine shouldn't they?

Thanks for all help given!:)

Romanx
 
You'll be fine for most tool and stainless steels and, afik, all simple carbon steels. BG42 austenitizes at 2050F. Not sure about S90V, but I think you are right that it is above 2000.
 
The only other thing you have to worry about with the electric is America is 60 hertz and Europe is 50 hertz. Would not make that much difference with the heating element but it will with the controls.
 
Never mind, I missed the part about it being European 220. I guess I really need to learn how to read. sorry
 
At 1500 watts, it may take a long time to heat up - even with the small chamber.

Also, I may have missed it, but does it have a controller? Many pottery kilns are designed to reach temp and shut down. You need some way of maintaining a consistent temperature - often for soaking times in the range of one hour at high temperatures and 2 hours at tempering temperatures.

If the kiln is top loading, give some thought as to how you are going to get the hot blade out. You can't leave it there to cool and heat coming out the top is just nasty! :eek:

Rob!
 
Yes, the kiln is a front loader and comes with a controller, but I'm not sure how accurate the controller will be. Are the operating temperatures extremely strict, or will a few (or a few dozen) degrees either way be ok?

Is it easy to attach some sort of temperature gague to see if the internal temperatures are accurate? If so what would I use? :confused:

Thanks.
 
If it has a digital controller, your oven is probably going to be fairly accurate. I think 1500W should be fine for the kiln if your inner dimensions are correct, it's about 40% smaller inside than the 1500W Paragons.

You can buy a pyrometer to test how accurate it is, I'm not sure how much the handheld jobs with a thermocouple run.
 
You could also get a PID. a ssr and a thermo couple from aubreins for around a hundred bucks and set it up to run digitally and hold with in a couple degrees,. Just a PID and a thermocouple would give you the true temps
 
No, the controller is not digital, its a pretty basic looking controller with a knob that is turned to control temperature.

I'll pretend I know what the PID etc are and how to install them;). What does PID stand for?
 
romanx said:
I'll pretend I know what the PID etc are and how to install them;). What does PID stand for?
Click to expand...

PID==Proportional/Integral/Derivitave

It is electronicspeak for an 'intelligent' controller that tries to mathematically anticipate the heating and cooling curves (in a temperature application, they are used in flow, heating, cooling, reaction, etc. processes in plants everywhere, industrial controls is my job these days) and adjust the rate of heating to prevent overshooting and undershooting the set temperature. Auto tuning controllers are pretty good. In the old days we had to tune them manually and it was a real art form!

Basically it is a lot 'smarter' than a simple thermostat and a well tuned PID will hold 1 degree pretty easily.
 
Roman, In many of these such discussions people have mentioned power ratings and it generally seems to be in the range of 3000 to 3500W for most ovens/ kilns.... Other people have regularly commented how painstakingly slow their ovens take to get up to temperature. I am with Rob on this being a concern. Your oven has a small inner volume, but just check with the supplier what they expect the time will be to get up to 1100C... It could be a source of frustration to you down the line if its slow.

Bridging phases is pretty simple with thermal appliances and the manual will probably explain it to you. 1100C is pretty sufficient for most applications.

Lang
 
I know that the slow heating comes up a lot here, but I want to point out that this oven is particularly small. Sugar Creek ovens are .49 Cu. Ft. and 1300W. These ovens are sloooow. I've never seen anyone complain about the 14" Paragon being slow and it's .19 Cu. Ft @ 1200W (had to go look it up). As long as the kiln you're looking at isn't using some sort of sub-standard insulation, 1500W should be plenty fast @ .125 Cu. Ft.
 
Thanks for all the advice guys. I'll have to ask about heat up times.

Regards,

Romanx
 
Hi Romanx.

I use a EFCO killn for heat treating since some years, mine is the bigger version with 2500 W an a chamber size of 350mm. Heat up time to 820°C is about 25 minutes.
 
Thanks for the feedback. I got a response from the seller that it takes about 90 mins to get up to 1100C, which seems slow enough to me, but then again I don't know much (anything) about this stuff really.

It might be a little on the small side, but if I can get a good price I might go for it.

In any case you have all given me some really helpful information even if I decide to go for another model.:)

Romanx
 
Romanx, This probably does not apply to you, but may be of interest to some others.

A kiln can easily be converted to a small salt pot.Just cut a hole in the lid to slip the tube through. Heat up time is not a critical factor with a salt pot. The plus is that a salt pot is a far superior HT source than an oven (most of the time). The negative is that you have to know what you are doing with a salt pot or you may be severely injured. A lesser danger is making a low temperature salt pot for tempering, or niter bluing.

If you have to ask what a salt pot is ,or how to use one, please don't attempt this retrofit.
Stacy
 
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