can epoxy be over cured

[olie25]

so when we pressed up are first few boards, we pressed in the garage not quite at room temp. although it says the entropy is only a 30 minuet cure at 180f we had to press for about 45 min at what the pid said was 195. is there some trick to setting a pid to heat the press up better. i guess what im asking is there anyway to overcook epoxy am i damaging the bond leaving it in a little longer and how much temp flux is acceptable.

[OAC]

You're about to get 1000 different answers now.
Best answer is(should be), ask the manufacturer.

[twizzstyle]

Ha, jan is right, so here is my answer to contribute to the 1000...

Yes you can overheat epoxy, but 195 vs 180 isn't enough. Are you using one heat blanket? Where is the thermocouple in relation to the heat blanket?

Only using one blanket, the blanket will be at 180 but the whole laminate will not. It takes longer to heat soak, especially in the middle where it's thickest. Previously using super sap I've done 180 deg heated from one side for one hour.

For the two pairs I just did this week, I did 150deg for 2 hours (as an experiment to try to solve base flatness issues).

[Richuk]

Hi Olie, what PID controller are you using?

Once you fix your temperature control, you'll be in a position to determine your approach to the epoxy you are using.

[Brazen]

Yes, any time the epoxy is left at temp over the time it kicks/sets weakens the final structure...plus, that long at 195 and you may end up blistering your base material.