Mick wrote:Just a thought............. A gas oven produces a lot of condensation, whereas an electric oven will be bone dry....... I'm no expert in the function of one as opposed to the other but it may be a factor.
Very true(ish)! Because the gas flame is burning oxygen it produces water vapour as a result (your point). That water can not condense because the internal oven temp is to high. It remains as vapour (steam) and forms a compound with the paint, giving a 'bloom'. I think! But I'm not a chemist!
Another thought. The colour coat will always 'cook' at a lower temp than the primer because then the primer does not have a chance to melt and merge with the top coat. Also, work pieces can be suspended by wire thro' 1/2 mm holes in it if they can be hidden upon assembly, but if the top coat has to reflow the paint might well sag and pool if surfaces are not horizontal.