Powdercoating Bicycle Frames

On bicycle forums, e.g. www.bikeforums.net, powdercoating of bicycle frames is a frequent topic of discussion. But there is a lack of authoritative information on the possible harmful metal-weakening effects of different powdercoating approaches and temperatures upon the alloys typically used in bicycles frames, chromoly and 6061-T6 aluminum. If one calls local powdercoating shops, they tend to say things like "I've powdercoated many bike frames and have never had any complaints."  But the reading I've done suggests there is reason to be cautious. 6061-T6 alloy can be weakened at 275F (I'm still looking for information on the temperatures chromoly can take). The typical "neighborhood" powdercoating shops, the ones specializing in motorocycles and hotrods, for example, use 400+F baking. Few have heard of the 250F powders or the new UV cured powders.  I don't know what you might be willing to do to help, but I'm sure any authoritative information would be appreciated by the thousands of bike-enthusiasts who are considering powdercoating as an alternative to painting.

Regards

T