On 2011-01-03, Tom Gardner wrote:
We just bought a used HT oven for $60. It has about a 1.5 cubic foot
interior and goes up to 2kF. It has an analog temp meter and a rheostat
that controls the on/off ratio instead of a temp dial setting.
Not really a rheostat (which is a variable series resistance),
but rather a duty-cycle control.
I forget the
name but one of the guys says it's a better but older make and model.
Possibly Blue-M? I've worked with one about that size.
I doubt it'll save us money on heat treating but it'll be fun and the guys
have a new toy...very important for morale.
Certainly. I would suggest replacing the duty cycle controller
with an electronic one -- Omega makes nice ones. Gunner has some of
some other brand used I believe. The duty-cycle type keeps inserting
that off cycle even when you are barely on the way up to temperature.
The electronic one (based on the behavior of my Omega which I fitted to
a smaller oven which I got with *no* controller) is that it will stay on
full time until it reaches about 75% of the set point temperature, then
it will turn off for a while and observe the overshoot, then it will go
back full on until it gets close to the setpoint and start cycling just
right to have perhaps a 1 degree F overshoot at 1850 F. Even with this,
it takes about an hour to get to set point. I'm not sure how long it
would take with the duty cycle controller -- I wasn't after as great an
accuracy back then. :-)
My question is: How hot and
how long to do a steak in there? Crusty on the outside and red in the
middle! Mmmmmm!
Hmm ... fifteen seconds perhaps? 0.0625" thick black outside,
and the rest red and jucy. :-)
Of course, it depends on how hot you get it first. (There is
also the trick of how you will get it back out if you don't have proper
heat treating gloves. :-)
Enjoy,
DoN.
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