Make your oven out of urethane foam insulation. Line it with aluminum
foil. Install 100 watt lightbulbs as needed to get the desired heatup
rate. I used 8 or 10. Put aluminum foil reflectors over the bulbs to
keep them from shining directly on the part and creating hot spots.
This is the oven I used to bond some honeycomb repairs to a Gulfstream
G-II flap, a 250° cure process. Of course, I used a hot bonder to
control and monitor it, but a simple thermostat would work just as well.

The biggest factor in your heatup rate will be the mass of your mold.
Less massive will make life easier. You'll need to have thermocouples
right on the part you're curing.

Don't use vacuum with a bladder. Apply pressure. About 2 atmospheres.
Make sure you consolidate your layup by applying pressure at
elevated temperature for a few hours before the cure cycle.

I have two Vision R-40's.

wrote:
I'm into recumbents and am exploring building a mold for a prepreg
carbon setup. This looks like an active site for composites.

Can anyone recommend a heater control to adjust the heating/cooling
ramp rate (5 degrees a minute, etc)? I'm obviously trying to keep
costs down so something surplus or homemade would be best.

Also, if I do a pressure bladder inside a female mold how do I apply
the vacuum between the composite and the inner mold line (so that the
bladder inflates)? Or should I just only apply pressure to the bladder
and not try to pull a vacuum on the mold?

Thanks airplane guys.

Joe



--
J Kimmel

www.metalinnovations.com

"Cuius testiculos habes, habeas cardia et cerebellum." - When you have
their full attention in your grip, their hearts and minds will follow.