nanner wrote:
I found a cheap convection oven (on sale from $70
to $40) and I have burnt 2 batches of test-pieces and the temp doesn't hold
consistently. I even *melted* polyfil!! wtf!!! I had a oven therm ometer in
there and it seems to hold steady for 10 min then increase 10 degrees, etc.

I am going to return it and there is this cheap toaster oven I am going to
try

A second option (to buying a used range) is to smooth out the
temperature lows and highs with a layer or two of ceramic tile. That
will help if the convection oven's thermostat is basically good, but
lightweight oven construction and relative lack of insulation is
causing the oven's heat source to cycle on and off too much.

You will have to let the clay tiles soak in the heat for a while before
putting in the poly clay.

Soft tiles (e.g, Mexican red, low-cost tiles) work best because
high-fired tile doesn't like to go up and down in temperature (like
non-Pryex glass).

All bets are off if the thermostat is lousy.

Dave