A guy in another newsgroup wants to make a small box for a pellet stove, and
so far, we've decided that if he can find a small piece of cnc punched
plate, that would be the way to go. I suggested post fab heat treatment.

Now, the question.

After you heat it up in an oven, say 500+ for an hour or so, do you let it
cool slowly, or dump it into oil?

What result do each of those actions do?

What he wants is to keep this little box from deforming, even with the small
fire of a pellet stove, and I've had questions about larger applications,
and want to understand more about this.

Good answers or good links appreciated

Steve

It ALL depends on what kind of material the punched plate is made from. If
it is mild steel, A36 for instance, it won't harden up or anneal anyway, let
alone at that low temp of "500+".
Thickness will matter a lot in this application. If the plate gets hot
enough to glow when in operation, it will oxide rapidly and, pretty soon,
there won't be any material left. We used to make maple syrup in a home
made evaporator fueled by wood. I made the grate bars out of 5/8" diameter
rebar. The bars didn't even last one season. They just got smaller and
smaller, day by day. Sagging is also a problem.

Cast iron works much better, as long as you NEVER allow ashes to build up
high enough to touch the grate from below.

Depending on the size of the device, if you can find a cast iron sewer floor
drain with appropriate sized holes or slots, that should work well.

Pete Stanaitis
---------------

"Steve B" wrote in message
...
A guy in another newsgroup wants to make a small box for a pellet stove,
and so far, we've decided that if he can find a small piece of cnc punched
plate, that would be the way to go. I suggested post fab heat treatment.

Now, the question.

After you heat it up in an oven, say 500+ for an hour or so, do you let it
cool slowly, or dump it into oil?

What result do each of those actions do?

What he wants is to keep this little box from deforming, even with the
small fire of a pellet stove, and I've had questions about larger
applications, and want to understand more about this.

Good answers or good links appreciated

Steve

Steel won't work very well for this application. It will quickly
deform.

as mentioned cast iron is the ideal. pretty hard for the home shop
type to do.

Stainless steel, #304, in a suitable thickness will work and can be
welded into the correct shape. You should know this material is a
stone bitch to saw or drill. It work hardens and dulls your tools.

Karl