Runny primer; edges of thin plastic items

[bhayss]

I have been practicing painting before my 'real' plastic ship model (1/98 Constitution).

 

I bought some Krylon primer at the auto parts store. It seems very, very, runny. Is this typical? When I try to paint an item like a rudder, or plane wing, the primer runs on the flat surface as I am trying to get the thin edge.

Does a primer coat need to be 100% coverage? Will a light dusting of the primer be adequate? If not, should i practice patience and put on two light dusting coats?

 

Many thanks -

[mtaylor]

Are you washing the parts first?  All plastic kits have mold release on them.  Wash in dish soap and water and rinse well. Try to keep your fingers off the surface to be painted.   Also, use several very light coats of spray and allow to dry between coats.  The coats should be fog like, thin, light, airy almost. 

[bhayss]

I didn't wash those parts. I will wash my next batch.

Is it customary to prime the parts while on the sprues?

[mtaylor]

Your choice.  Back in my plastic days (cars, tanks, ships, etc.), I usually painted on the sprue and then touched up after cutting it off.  However, some parts need to be assembled before painting, in that case, with small parts, I got a pin hot and stuck into the part(s)/assembly in a non-visible location.  The bigger parts just needed a jig.  For example on a car, the body was assembled with masking tape in the hidden areas, the whole thing mounted on a carefully bent coat hanger and painted.  Not just primer, but the color and clear coat also.

 

There's a lot of different ways of doing this. I'd suggest check the Kit Log area out on how they've painted.  Even with the wooden kits, the same techniques would apply.