On Oct 29, 3:28 pm, JJ Sinclair wrote:
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

Lots of experience here !
Yield temp is just a bit lower than when it starts to turn brown ;-)
Last time I did this I just used a hair dryer and gradually increased
the heat until the part gave a little easier.
There's got to be a better way to quickly judge it though ?
Maybe Bumper can recommend one of those nifty strips that
changes color at just the right temperature ?
See ya, Dave "YO"