Thermolyne Dubuque II heat treat oven

[JG Custom Metal Works]

I have a line on an older heat treat oven from a retiring local knife maker and was hoping to get your guys' opinion on it. Obviously it doesn't have a lot of the newfangled features of current models but I can get it for fairly cheap. He's wanting $200 for it and is throwing in a three pairs of blacksmith tongs(which I need) and "quench oil." The tongs themselves can be around $35-$50.

It's controllable via a thermocouple sensor from 0-2000F and runs off 220v. Inside dimensions are 4" x 4" x 9" deep. It definitely looks used but he says it functions 100%. Only issue that I can see is that the bottom brick appears to have a crack in the middle but he says it doesn't affect function.

Here's some pics:





I have an Atlas Mini Forge on the way but otherwise have no other means to heat treat. Should I jump on this oven or just hold off until I'm able to afford a modern oven? Any input would be greatly appreciated.

 

[Stacy E. Apelt - Bladesmith]

Well, it is old and heavily used, for sure.

The plus:
Low cost...that's about it!

The minus:
Will only do small knives and folder blades.
Will probably have issues with coils sooner or later.
Will only do carbon steel HT.
May not have precise temp control.

Those are basically dental burn out ovens. Temperature control is not important, just that it get hot enough to burn out the wax.
A 7" OAL blade is about the max for that kiln.
While the dial says 2000F, my car speedometer goes to 120MPH....both are wishful thinking. They are good up to about 1800F max. They do fine in the 1500-1600F range.
While I haven't used that exact oven, on most of that type, the controller is analog, and you have to babysit it to maintain a temperature setting. +/- 15 degrees is about as tight as you can get them to hold. Most heat very slowly, too. That could be changed to PID control, but it wouldn't be worth it for this oven.


If it is all you will have for a while, and you are only doing small hunters, then it will be a good deal ( maybe). If you plan on doing anything but small simple blades, save up for a paragon/evenheat/etc.

 

[Justin Presson]

I seen that one to and at first thought oh HT oven localy! But the more I thought about it the more it did not look as good Iike Stacy said it really limits the size of the knife and if something breaks not sure I could find parts for it. But throwing in the other stuff definitely sweetens the deal a little.

 

[JG Custom Metal Works]

Thanks for the info Stacy, I appreciate you taking the time to post. It seems like this oven might be more trouble than it's worth. Not being sure of the actual temps seems like it could lead to being a very frustrating endeavor.