Just wondering how many of you go the extra distance and post cure your parts?
Would it be suffecient to have the parts in a old stove on a low setting? How do you guys do it?
How critical is it for non structural parts?
if its non-structural then its probably non-essential to post cure.
Although, I had made a few apillars in the past from a certain epoxy that wept and deformed slightly due to the attachment points. Seems that the heat from the sun softened the resin and the pillars drouped down. The customer had to support the pillar while it cured and cooled down. after that there was no more problems in hot weather.
Apparently once the epoxy sees a certain temp then that is its service temp range.
20_rc…use only an electric oven as the gases can be flamable.:eek:
after talking to an epoxy ‘expert’ that has had considerable experience building peices for high stress and heat application, I was told that peices should be post cured to the highest temp that they will be put to use under. Apparently if parts are not post cured they can experience heat shock and get damaged/distorted. As well, some epoxies require post cure to reach max strength.
It is very important to ramp the temp up slowly as to not exceed the Tg at that point of your laminate. Otherwise your laminate will soften up and all the stresses from the compressed fibers will start to show, it not be real print through but you will get some fiber float. Bring up the temp slowly to gradually increase the HDT. Only about 2-3 degrees per hour if you can.
I use a type of oven to cure parts in the winter as the temp in garage can make curing long. I make a of rigid foam insulation and use sharp spikes (tent pegs) to hold it together. I then put an electric light in there and it soon heats up, put 2 bulbs in there and it gets very warm. I did use a thermostat but found it was easier to just switch bulbs (ie 40watt or 60 watts etc) to get the temp I wanted. When finished you can just pull the spikes out and collapse the box and stash in away somewhere. Or on a sunny day( not very often here in the uk!) I put it in a black bin liner and leave it out in the sun, or in the car if the wife isn’t about!
I post cure all my part’s for 2hr’s at 120 to 140 deg. I had a problem with the fabric print showing after the part got hot in the sun and post curing has helped that.
I use a heat lamp in a old metal tank as a oven.