Re-shaping fiberglass parts with heat

I knew the concept was valid from Schempp-Hirth instructions on how to
heat up an early Cirrus wing and put in the twist that Cirrus's after
s/n 175 had. I have a badly twisted gear door (corner stood proud a
good 5mm), so I thought I'd give it a try on a much smaller scale. I
held the gear door in front of an electric space heater for a good 8
minutes, until it was too hot to leave a finger on the surface. Then I
put it in place on the wheel-well (fuselage inverted) and held the
ends with two 25# shot bags. I slipped in a 5mm shim to achieve over-
twist for the expected spring-back. Let it cool for an hour and it
fits like new!
Anybody else have experience heat-twisting epoxy/fiberglass parts?
What's the yield temp?
JJ