Curing question

[tomg552001]

What would the cause of easy chipping be on the powder coat? It seems that at times, the powder chips easily. Could it be that i am not curing long enough? I degrease the valve cover, than bead blast with a glass bead alum oxide combo, followed by pretreatment. Than i prebake it for about 10-20 minutes at 375, spray powder, and cure another 10-15 minutes at 375. I am coating mostly cast alum valve covers and intakes. Any tips and suggestions on curing for the toughest and strongest finish would be appreciated as i think others might be having this problem aswell. Thanks in advance.

[Fireblade]

Possibly with the cast valve cover that you aren't getting the part up to the full temperature. Not sure if this is what you do or not, but this is what ya need to do. When the part is in the oven, keep checking its temp, till you reach the desired temperature you want. Just because the oven is 375 degrees, doesn't mean your part is 375 degrees. the part has to heat up to reach that temp, which takes longer on heavier, thicker pieces of metal, shorter times on thin, small pieces. For instance, say your cure time is 10 mins at 375 degrees, the part may take 45 mins to reach 375 degrees. That would be a thick cast piece taking that long, but just an example. Do you have an infrared temp gun? If not, would be a wise investment to do so. Stop pulling your hair out, and know the exact temp of the piece. Under cure can cause brittleness.

[adambond]

are you using an IR (infrared) oven. if so its probably shortwave and they typically only heat the part surface quikly while taking longer to heat the sunbstrate . but you are probably using a regular electric oven im guessing, which evenly heats very well. maybe its cheap powder. ive had powder that wouldnt even resist rubbing alcohol.
ADAM (just trying to get a higher rating) BOND