Hey guys just had a weird situation, I demolded a part and I left it by accident under an infrared lamp and after a few minutes it became extremely soft and flexible. Is it the epoxy’s fault? the tech sheet says it’s up to 60C degrees. The part was laminated 48hours ago. Any ideas?
Did you let it cool DOWN before demolding? I’ve had infused parts spring back into uncompressed shape and fiber orintation after a post cure non-vac bagged. REsin went soft, and Z fibers sprang back.
Yes I let the part cool down for few hours, it demolded just fine, no signs of softness while demolding.
Interesting. No idea 
Call the manuf.
If will soften on the way to post cure, and then reach full stiffness and strength. If the resin is not made to be post cured unsupported, it can deform the part.
I have same thing. When I was cleaning new mould from PVA with pure hot water whole mould started to be really soft. But there was no postcure. No degradation in shape.
normal epoxy’s fully cure after seven days, dependent on teperature. After two day’s most parts are noticably less stiff than after a week of curing. When for a reason the temparature at night is less, the curing will slow down.
How hot do you think it will get with hot water and under a light? 
post curing is the way to rise the Heat Distortion Temp. Every epoxy does benefit from that! (stronger molucule links, so you have a better stiffnes also ;))
Yes, that make sense,post curing raises the heat distortion temp, but even if the epoxy cures at room temperature is it possible to become soft under the heat of sun even after 7-10-15 days of demolding? Does this happen only with epoxy resins because I never had this with polyester resins.
In sunshine black surfaces can heat up to well over a 100 degrees celcius (I remember something of 95 degrees celcius in about 30 degrees surrounding temp.) SP has some data about that.
Edit: I uploaded it, here you go: www.composietforum.nl/downloads/surfaceprint.pdf
on the dutch compositeforum webspace
Cheaper epoxy’s don’t withstand temp. as well as polyester resins do. Most polyester resin I use go to about 90 degrees celcius.
Lots of great info! Thanks!!!