[Fireblade]

Hello all, I have a question that I have been wondering in my mind for a while now. How long do you actually cure a part in a oven? And at what temp? Is this temp the part temp or the oven temp? Here is what I have found from experience doing this. First off, I used to preheat my oven to 450degrees, then place my coated part in, let it flow out, then drop the temp to 400degrees, and let it go for 20 minutes. Pull the part out, I compared this to "Professional" shops jobs, and the powder on my parts came off alot easier than theirs. So I toyed around, and I tried this, I would preheat the oven to 340 degrees, place the coated part in the oven, then wait, I would check the part temperature every 5 mins waiting for it to achieve a 320 degree part temperature, then I would set my timer for 30 minutes. I just recently did this on a set of Harley heads. I have been told that if you bake aluminum (mainly t-6061) past 350 degrees, it could cause a chemical change in the aluminum itself and weaken it. Now after I did the cook process the second way, my parts seem to have a much more durable coating on them. What is the right way to do this cure thing? Now the Harley heads are cast aluminum, and quite a decent size, so they heat up slower then a thin gauge steel or something like that would. Here is another question, I am building a large oven myself. If I put heavy cast pieces in it, with smaller objects, would this make for a over baked finish on the small parts and underbaked finish on the large parts? Thanks for any info on this. I am kinda confused, I have done many parts, some turned on good, others I was dissappointed with. I want to to have a definitive answer to this cure thing to ease my mind. THANK YOU!