HT oven advice (particularly for a 45" oven)

SBranson

SBranson

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Oct 29, 2006
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I know, I know... the same questions over and over...

But, I am looking to get a HT oven, either Paragon or Evenheat and am just looking for a little advice.

Because I enjoy making swords and intend to make more, I am tempted to go all out and get a 45" model. But, I suspect that swords will not be the majority of my work so I also think of getting a 24" oven and figure out something like a warm oil bath for swords or temper them in my kitchen oven. The only thing against that is I like the idea of using the oven for thermocycling.

Just wondering if someone will say "don't get a 45" unless you plan on doing lots of swords because they aren't great for smaller blades".. or something like that.

Thanks
 
It occurs to me to wonder how much more energy a 45" oven consumes per hour to maintain a particular temperature than, say, a 27" oven... or a smaller one. The underlying question would be how long would it take before it made good business sense to have two or three ovens so that you weren't wasting money heating smaller knives.

Also, does anyone have any Mean Time Between Failure (MTBF) numbers for the various sizes? Are the coils prone to degradation at the same rate regardless of length?
 
Yeah, I was wondering about consumption but never even thought about that second comment.. Hmm.
 
Damn.. now more questions. Inner dimensions of the 45" Even heat are 10" x 6.5" whereas the Paragon is 4.5" x 5.5". Would make the Paragon more efficient but would that be limiting. But, the Evenheat has 2 doors.. could mean I can do several blades at once with ease... Hmmm.
Price with shipping works out to the same.
 
As long as we're bringing up questions:

(1) - if you get two ovens, you can always use the larger one for tempering knives heat treated in the smaller oven, so it might be useful to have both.
(2) - On the other hand, if I were making swords, I would probably try to do my heat treating with salt baths as there is little or no decarb, so cleanup is (reportedly) MUCH easier.
 
Thanks. Well at $2500 for a 45" model then to add another $1500 for the 24"... a bit too much $$ at the moment. I can get either but not both.

I'm more thinking thermocyling and tempering for swords. For Japanese style blades with water quench, salts would not work so well both for the clay and that I need to keep the spine below austenitizing temperature to prevent cracked blades.

I think the final piece of this puzzle may end up being as simple as the plug.

The Paragon uses a Nema 6-20P whereas the Evenheat uses a Nema 6-50R plug that's the same as my welder which I am already set up for.
How easy it that to change?
 
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Thanks.. I figured but I wasn't sure about the rating and such. I just don't like messing around with 240v much.
(nor do I want to void the warrantee)
 
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I think there's a reason why so many sword makers end up building an HT oven, furnace, or salt pot for sword work. I'm in the same boat currently. I need a real device for precise thermal cycling, and it's the last big piece of gear I've put off for too long. The more I look at the prices of both the evenheat and the paragon's, the more I'm leaning toward a DIY solution.

Gas actually seems to cost me less than electricity considering my highly overpriced "electric co-op", and I've still got a fair bit of cerachem left over, so I may just go that route. One thing that occurs to me about a DIY solution is that it shouldn't be too impossible to make a modular setup with two blown burners, that could be walled down to one burner and a smaller chamber size most of the time, to save on fuel, then opened up when needed for larger stuff. I'm sure an oven could be build using high temp elements also along the same lines.

Maybe I'm missing something though.
 
Several of the oven types can be "stacked". You remove the end and clamp them together.You can make the assembly horizontal or vertical.
David Catoe uses three 18" ovens for his blades. He stacks them vertically as needed for swords and daggers to get a 36" or a 48" HT oven. He cut a small opening in one door and lowers in the blades on a stainless hook. He places a fire brick over the hole while heating. He ran three circuits from the power panel to a box on the wall next to the HT area. He also mounted his large readout pyrometer there too. Each circuit is a 220VAC 20 amp circuit. That way, each segment has its own power supply circuit from the breaker box.

When he is doing normal blades, he takes the top unit off the stack and puts the door and end back on. It is a regular 18" oven then. The stack is still a 36" oven.

IIRC he paid about $2200 for everything.
 
I think Sugar Creek makes stacking kilns.

As for the plug: I have one plug type in the wall, and a different one on the kiln. It would have been easy to change the plug in the wall, but than my KMG wouldn't have plugged in. So I made a 1' extension cord with the right plugs at each end to adapt from the kiln to the wall. As I understand things, is OK *provided* the think getting plugged in is of lower amperage the wall is capable of providing (of course, you should talk with an electrician about your specific application).
 
You could probably build one oven with 2 sets of elements. A front and rear set of coils that could be seperated by a brick wall when working on normal size blades, and then remove the brick wall and apply power to the rear coils for your swords. This is if your talking about a horizontal unit. Just a thought.
 
Stacking kilns.. Genius!! It would be better for swords to hang vertically too.. Neat idea.

Turns out for $50 Paragon will change the plug (and I get to keep the warranty). I looked into doing and jumper cord to adapt the plugs when I got my welder but you wouldn't believe how much trouble I had finding parts locally. Seriously.. everyone was out of parts.
I ended up getting a dryer plug to 6-50R extension cord and would just plug into this.

Best would be a combination of the two machines. I like the double doors of the Evenheat but the inner volume and apparently more robust build of the Paragon. I think I'll end up with the Evenheat because in the end it's cheaper and the extra volume might be better for not dinging the sides putting in a long curved Katana.
 
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