Hi Folks,
just wondering about undercoating/priming a model? I've just dunushed a lovely 1:35 88mm from Dragon, but have never painted a lkit like this and want to do it justice- I'm sound with details, weathering an all but should I just spray the whole lot black and work from there, or would brass/aluinium parts need to be masked ?
Any advice appreciated!

As a rule, undercoat the lot. The more different media there are, the more the need to "even them out", or you'll find the actual paint behaves differently on different surfaces. I'd go for a true primer rather than a base coat of any ordinary paint - some of the best value ones come from car parts shops like Halfords.