I agree  with Wajda Cory concerning the baking of multiple layers, but more to
the point why are you coating 5 layers to get 30 microns?  Especially with 4903
you should be able to coat in one, but at the most two steps, not five.  I guess
it would depend on your requirements for edge bead height, width and overall
uniformity.  If you have specifications for these I might be able to suggest
process steps that could help.

Clif