I'm very interested in hearing what experienced folks have to say about this. I have a Paragon oven, and have been using it for years. I have toyed with the idea of a salt bath, only because one of my primary steels is O-1 and it supposedly responds extremely well to the salt regimen. I have almost everything I need to make one salt pot and was thinking of making a low-temp pot for tempering rather than a high temp pot for hardening. Only because you can use a variety of anti-scale coatings and reduce the scale considerably, if not eliminate it. I would still be using the oven for initial hardening.

I can count on one hand the number of knifemakers that have been using a salt bath longer than I have, and I would say that if you have a reliable and accurate oven that can do an argon purge, or you are happy with anti-scale, the oven would be the cheaper, safer and more hassle free route to take. For a while it seemed like ever new maker felt that they could be an instant success if they just threw enough money at a salt bath rather than just putting in the time required to be a really good knifemaker. But there is no fancy gadgets that will ever replace time in learning the skills, and, without that, all fancy equipment will do is allow you to make lousy knives twice as fast. This, coupled with the number of near death experiences I have had with salt baths, is the reason I took all the salt bath "how to" information off my web site.

On the salt baths- If you are not really sharp with selecting and wiring the proper PID controllers with proper relays, (heavy duty mercury displacement for electric heating, or proper solenoid burner valves for gas), you are probably better off going to Evenheat and buying a premade salt bath unit, but one of their kilns, or Paragon's, will be more versatile at a lower cost. I have seen salt setups without proper controls and it was a painful mess to behold. The whole purpose here is unsurpassed control of a very even heat, without a proper PID, thermocouple and relay system all you have is a really dangerous pain in the neck.

Next you have the salts. You need to buy the right stuff. The main reason I stopped giving out advice on salt baths was the number of people who contacted me and said that they had their salt bath rig setup all built and now want to know if they could use water softener salt or sidewalk de-icer. My astonished standard reply was "so let me get this straight, you just told me you have built something about as benign as a nuclear reactor and now you are just getting around to ask somebody what this "nucular fizzyun" stuff is all about? The fact that they were already cheaping out on the salts told me that this was a train wreck waiting to happen. Proper salts for salt baths are not easy or cheap to obtain. If you go with the most basic, like Park Metallurgical Nu-Sal (good luck with that) you will not have any hazardous material concerns, but you will top out at 1,600°F. But even these most basics of salts are carefully neutralized so that they will not decarb and destroy the surface of your blades. These salts need to be maintained, they need to be checked and rectified with special additives regularly or you will wish you had just used a kiln with the decarb you will get. If you go for a higher temperature rating you can get other high temp salts from many more sources, like Houghton, but you will then have to deal with the toxic heavy metal additives. Some middle man suppliers sell the salts in smaller quantities, but they have to make a living from doing it, so the cheapest way to buy the salts is from the big guys in 400lb. drums.

If you don't go with something premade from a place like Evenheat, you will also have to work out the tube situation, and this has been the single greatest challenge for the whole salt bath thing, that I have encountered. I have had terrible luck with tubes, and when they leaked they cost me thousands of dollars in kiln components, before I went to gas. The best way I have found to insure they don't leak is to use 316L tubes, which run from $500 to $800 to procure. You will want to set the high temp units up somewhere where the spatter or vapors will not turn anything with iron in it in an 8 foot radius bright red. And I am not even going to get into what can happen to you if you get careless with 1500°F molten salts, but I could write pages on it.

I have both kilns (Evenheat and Paragon) and salt baths, and for what I do, between swords and metallurgical research, I need them all. But if I were starting all over as just a knifemaker, I would just get a good kiln and call it good.

Kevin I watched your videos on You-Tube and between those and your post here I am convinced that the Electric Kiln is the way I am going!! I think its going to be a Paragon 23" with the purge on it. I just need to do a little more research on the control for it. I was also toying with the idea of building one and I may. I live very close to Sheffield Pottery so light weight refractory fire brick are $4.03 ea and a little bit of gas no shipping! Thanks for putting this question to rest for me!

I went through this. I went with a electric kiln. To much to learn with the slat baths to figure out on my own.

Here is one I built with stuff laying around my shop. But Kevin is right about proper PID's and solenoids. I have ordered a better PID and solenoid. And I am going to redo my burner. This PID I am using was for another project. I have a ramp/soak PID coming so I won't overshoot my temp. My SS tube is 2" 316LSS 18" long. I should of took a pic of my tube. I got it from a pipe supply place. Its schedule 80. I had it threaded. I put an 316l ss steel cap on it and welded it up. I figure it has double fail safe with it being threaded and welded.

https://youtu.be/FgFHiy3pUOA

Here is an oven I built. I used a TAP controller on it. I have around 800$ into the oven and around 350$ into the mini salt pot.

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Here is one I built with stuff laying around my shop. But Kevin is right about proper PID's and solenoids. I have ordered a better PID and solenoid. And I am going to redo my burner. This PID I am using was for another project. I have a ramp/soak PID coming so I won't overshoot my temp. My SS tube is 2" 316LSS 18" long. I should of took a pic of my tube. I got it from a pipe supply place. Its schedule 80. I had it threaded. I put an 316l ss steel cap on it and welded it up. I figure it has double fail safe with it being threaded and welded.

https://youtu.be/FgFHiy3pUOA

Here is an oven I built. I used a TAP controller on it. I have around 800$ into the oven and around 350$ into the mini salt pot.

What are you getting for a Ramp/Soak PID? If I build an electric oven I would like to use one for my project. Thanks!!

|quoted:

What are you getting for a Ramp/Soak PID? If I build an electric oven I would like to use one for my project. Thanks!!

I'm going to use a ramp/soak on my mini salt pot. The one I have on there will overshoot temp. I would use a TAP controller on an electric oven you can order them from SDS industries. You can save different heat treats. Set it for a thermo cycling pprogram.