heat treat oven ?

S

stlsrgn

Joined
May 7, 1999
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I'm ready to buy a new heat treat oven, I'm leaning towards the 18" even heat knife oven with digital controller, I'd also like an oxygn free atmosphere.I have a bottle of argon and a flow meter.Is this a good oven to buy? Is the paragon a better oven? Where is the best(least expesive)place to buy one? Where is the best place to install the inlet for the shielding gas? What gas is best? Argon,Co2,A mix of both? Any info-comments are greatly appreciated!!!

Thanks
PJ CAREY
 
Do a search for Tim Zowada's knife site. There you will find his number or email address. Contact him about purchasing the Even Heat.

Many love the Paragon. I have the 18 inch Even Heat and am glad, but can not compare it to the other makes.

Roger
 
I just bought an evenheat for sheffields. It is easy to program compared to the older ones. I would not try to put a purge in the oven. It is lined with very close fitting fire bricks. You always run the risk of breaking a brick when you start drilling, even with a hammer drill. As for argon and co2 they are for welding. if you are trying to keep the blades clean you need nitrogen. I double wrap my blades with stainless .002 and have gotten good results.
 
Weld,

I too use the 0.002 inch wrap. I have only double wraped one blade so far. That was because I got a pin hole in the first wrap. All my other blades have been single wraped and I have gotten no noticible decarborization - yet(thank God). I mention this because I know how expensive the stainless wrap is.

EDIT: I forgot to mention that I do include a small piece of brown paper bag in the packet to help expend oxygen trapped within the packet. If anyone knows of a cleaner burning substitute I'd appreciate knowing of it. I've thought of using a smidgen of wax but am afraid it may vaporize and explode.

RL
 
I have a friend that is a journeyman smith who has the Paragon, and he is totally disappointed and disgusted with it. I have no personal experience with the Paragon, but my friend says he has to continually replace parts on it. I just bought an Evenheat and so far I am very pleased with it.
Hope this helps.
 
I have an even heat custom built 28" rampmasterII
I've had good luck with it.
I do wish I went up to the next wattage though.
argon is used for atmospherizing ( spelling) metal
used for that purpose and OK to use on knives too..
don't use CO2 though, it will mess up the elements
in the oven with time.
I haven't used nitro but they say it's OK to use.
evenheat
(at least the last time I talked to them)
(edit),evenheat, does not have an argon set up for their ovens
Paragon does, at about $150.00
you'll have a hard time picking the
parts for that price. when you air quench you may want to do it in
a can and flood it with argon until it cools enough so it won't
carbonize while cooling out of the oven
you'll have to be sure it cools fast
enough in the can too but not to fast.
you can use a reg drill bit to drill the soft brick just clear the drill bit often..
 
I've got 2 Paragons.
The oldest (14 yrs)is a KM14D and the other (10 yrs) is a KM9D. I updated the 9 to their new Sentry controller and put the KTC600 on the older one.
I think I have burned one element out in the 14 and none in the 9. I use both of them at least once a week, sometimes more, depending on what steels I'm working that week.
I looked at the nitrogen or argon set up on one at the Blade show and decided to stick with foil. I use both low and high temp foil.
No complaints on the Paragon oven.
 
Kit,

What do you use the low temp. foil for (tempering?)?

What do you use as low temp. foil. I have only seen the 2000 F. foil.

Thanks,

Roger
 
Argon is a good choice for this application because it is much denser than air and will displace the ambient air in the furnace far more readily than nitrogen. Since air is about 70% nitrogen, the densities are about the same. If you use a gas purge, you may want to consider the Paragon because I "think" you can program a solenoid to turn on only at the temps you need with their digi-control. Perhaps Plain Ol Bill will chime in here, he has this setup.

There are two caveats with argon: the first is the cost.. it is more expensive than tech-grade nitrogen usually.
Second, it displaces air so well it can also suffocate you quite easily. It will sink to the floor and displace the air. If you leave a purge on for the entire cycle, and have a small closed shop, I'd make the cat sleep up off the floor!:D Use good ventilation when using argon. It is hard to expel from the lungs because of the density.

I have a KM14D Paragon I've used without problem since about 1985. It recently finally needed a new thermocouple. Considering the expense of converting to programmable, but it's over $500. Good furnace....

rlinger.... i've recently quit using any "burn-out" paper or cig-butt etc in the pouch and notice no difference whatsoever. In a well sealed envelope, the amount of oxygen is apparenntly minimal.
 
Fitzo,

Thanks for the paper tip. I'll try one without it.

If you get it in your lungs, or the cat's, stand on your head or have someone you don't like hold the cat by its tail.

Roger
 
Roger,
I should have said high temp and higher temp :)
I use the 2000° foil for almost everything but the S90V (2150°). With the new Sentry controller I can go up to 2400°. McMaster-Carr sells a foil that goes to that high temp.
 
The shop I used to work in, had weld huts. The weldors would sit in the huts (close's off stray air currents) and TIG weld tubes.

Sometimes the Argon was so thick the weldor would have to lay with his feet in the air to clear his lungs.

Later they hooked a vacumm cleaner to hole in the floor to exhaust the argon.

So yeah, basement operation hmm.

I like the purged canister idea better. Besides less gas use.

scale prevention

read this article at the bottom of the page by Terry Primaos
 
If anyone tries the PBC compound, pay special heed to Terry's temp comments. I recently tried this on a damscus blade. Tried normalizing it coated after grinding, then hardening, based on Admiral's HT info temps on 1084. Thus, it had 4 cycles, 3 of which were in slight excess (1625F) of Terry's claim but lower than the label claim of 1650F. It corroded and pitted so badly that what started out near 1/4" had to be ground down to about 5/32, and I've now got one of those "disappointments" sitting around.

Out of curiosity, I called the tech department at Brownells to inquire as to the composition. All they could tell me is it contains boron. They sent me an MSDS but it didn't state anything more than "contains boron". Something in this mixture turns very acidic at elevated temps, so I recommend it be used for one temp cycle well below 1600F and removed in boiling water immediately. This caused enough stir at Brownells that I got a personal call from Frank Brownell, offering me a "compensatory" can of the powder, which I declined cuz it was my screwup. Haven't tried it again, but, DANG, didn't it turn out great on Terry's blade.

Obviously, this stuff isn't for stainless...temps are wrong.
 
I bought a paragon KM24 at the last blade show and had them put the argon flow meter and tubing on it. I had "assumed" this was a high pressure flow meter and that you hooked straight to it from your bottle. Not the case - you still need a high pressure flow meter on the bottle and the one on the paragon is a low pressure. We heat treated some S30V and the expenditure for the argon made foil look a lot more attractive. We used about 400 cubic ft. of gas to heat treat the material. I love the oven and the digital controls but if I had it to do over I would have saved the 200 bucks spent on the gas set up and used it for something else. Just my .02 worth guys.
 
Kit,

That clears it up. I didn't think eliminating oxygen from tempering temperatures would help much but that was the only thing I could figure you'd want it for. I'll check out the vendor you mention because I most probably will be trying s90v and my Even Heat specs to 2200 F.

Thanks for clearing that up.

Roger
 
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