# Heat treat oven or Kiln?



## aliva (Jan 22, 2017)

I'd like to build a heat treat oven. I've seen several plans on the net and they don't seem to be to difficult to build. 
I've checked various sites where I could just buy one already built,  this would certainly save a lot of time and effort. But the pricing is more than I'd like pay.
 So I got to thinking why not buy a used ceramics kiln, there are a lot  available for reasonable prices. Most will produce a max temperature of up to 1800F. more than enough for my needs
Some kilns have manual rotary temperature adjustment, but I'd prefer a PID controller. which is not difficult to add in the future.
My question  is can a kiln substitute for a heat treat oven?
Has anyone done this/?
Any thoughts would be appreciated


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## Terrywerm (Jan 22, 2017)

I have not done this, nor do I know anyone that has.

I believe that heat treat ovens have finer temperature control than kilns do, in fact I am quite certain of it. Converting a kiln to fit your needs may not be a bad idea, but I think you would be better off converting it to PID control right away.


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## randyjaco (Jan 22, 2017)

I have been using a small kiln for years for heat treating.  So far I haven't had any problems with temperature control. 

Randy


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## eeler1 (Jan 22, 2017)

Yup, if the kiln can hit your temps, you can put all kinds of controls on it, from a basic temp gage to a controlling unit.  I have one that was unreliable in terms of temp, but after installing a temp gage works pretty well.  Just gotta watch it because it is hard to maintain temp.  Better if it had a controller to maintain a particular temp.


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## Tony Wells (Jan 23, 2017)

One our members projects might give you insight into what it takes to build a decent one:

http://hobby-machinist.com/threads/heat-treat-oven.9929/


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## Ironken (Jan 23, 2017)

Watching this thread! I could use any ideas you guys wanna throw out there.

This is what I have. About $900 from Delphi Glass......my wife calls it her ceramic/glass kiln and it's too small for her needs. I call it my heat treating furnace. It has a fully programmable controller and a TC midway up the wall. Is it a highly accurate HT furnace?....No. I have yet to give it a go but, I think it can be made useful.


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## kvt (Jan 24, 2017)

That looks nice,   What range does it have.   I have never used one of those.


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## Ironken (Jan 24, 2017)

kvt said:


> That looks nice,   What range does it have.   I have never used one of those.



I have never used it to HT metal yet either. Max temp is 2000 f. I'm itchin to try it though!


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## aliva (Jan 25, 2017)

Thanks to all that responded.
i'am going to starting looking for a Kiln


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## Tony Wells (Jan 25, 2017)

About the only serious negative I've heard about using a kiln as a metals unit it the fact that the top opens to get to your work. We all know that heat rises, and when you open a kiln, the hot air rises and creates an inrush of cooler air to replace it. If you're annealing something you want a slow cool so would probably ramp down slowly and it wouldn't create any problems, but I'm not so sure about opening a kiln at quenching temperatures. I guess you could detach the lid and rig up a way to run it upside down and just lift the main body off the lid, which would serve to support your work. Probably would require some modification, which of course may not go well if you are sharing this with a potter.

Then again, it may not be such a big deal. I haven't done it myself.


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## mksj (Jan 25, 2017)

There are a number of manufactures that make small ovens/kilns for jewellery, knife making and heat treatment that are relatively light, they heat up quickly, and they have a number of programmable features.  It will hold very tight temperatures and some have features to flow inert gas in the heating chamber. I use a small Paragon oven, but the interior size is a bit small. The knife making ones tend to be a bit longer. Prices can vary quite a bit but I have seen ones with a PID control starting around $600. Pottery kilns tend to be much heavier, are slow to reach temperature and can be hard to keep the temperature in a narrow range. 
https://www.dogwoodceramics.com/product/paragon/paragon-metal-heat-treating-kilns-and-furnaces.htm
https://www.dogwoodceramics.com/product/paragon/paragon-knife-making-kilns.htm
http://usaknifemaker.com/knife-maki...and-accessories-c-57.html?dir=asc&order=price


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