New (old) heat treat furnace - looking for help

TLR

TLR

Gold Member
Joined
Oct 5, 1998
Messages
1,574
Well over Thanksgiving my wife's uncle let me know he had picked up an old heat treating furnace and was willing to let it go. This guy has a large shed/workshop filled to the rafters with stuff he finds all over. He even found and rebuilt a really nice little giant power hammer.

The furnace was made by Hoskins Mfg Company, model number FD202C. It looks to be in really good shape considering it's got some years on it. There seem to be no cracks in the firebrick at all and while I haven't heated it up to temp I did plug it in and make sure the element at least heated up.

It uses an old rheostat as a control mechanism and therein lies my biggest fear with this kiln. I'm not at all confident in the old wiring or the rheostat to keep a consistent temp. I quickly read through the stickies on PIDs and may move in that direction but need to do some more research.

Below are a few pics. Hopefully I didn't buy something that isn't practical due to it's age. Any and all advice or information on this kiln or in general is appreciated.

attachment.php

attachment.php

attachment.php

attachment.php
 
That is an ancient beast of a burnout oven.
It should work for smaller blades in carbon steel.
It will take at least an hour to come up to temperature, and you should soak the oven for 15 minutes at temp before putting in the blade. 1600F is probably the max usable temp it will hit.

The PID instructions for a toaster oven conversion are the same as you will need for this oven. It should run about $100 to convert it.
 
I have the brother to yours, it was slightly updated at some point with a metal box with a control knob, but there were no witness marks or calibrations. The only thing I’ve used mine for so far is making some mokume, it was easily hot enough for that. I don’t have my notes here, iirc when I did a test run it went to better than 1600 deg F, and I think bladsmth’s 1 hour to come up to temp is a bit optimistic, I’m sure it is partially due to how much use and abuse it’s had, mine came out of a school. It took a while to heat up, but was quite steady according to my pyrometer, there is a lot of mass in that hard brick muffle for such a compact furnace.

I need to look at the PID instructions that seems both more flexible and economical that what I was thinking about, something like a TC-3A from Thompson Enamel. A visiting artist brought his own TC-3A to a workshop and it gave him good temp control on our old fixed temperature kiln.

Todd
 
Thanks guys. I appreciate the input. So here's the big question in my mind. Is this older oven worth putting the time and effort into or did I waste $100?
 
$100....you are OK. That is about the top value. Do the math - 1200 watts - and compare the power to a Paragon or Evenheat and you will see where the difference lies....that plus a good controller.
 
Thanks bladsmith. I appreciate your help, insight and encouragement.
 
You must log in or register to reply here.
Back
Top