efficient spot priming

Tamiya also has 40 ml bottles of brushable "Liquid Surface Primer" (which can be thinned for airbrushing if required) - Part number 87075.

It's a lacquer based product, so it's pretty "hot", but it means it dries very quickly. Having said that, it does self-level very well before it dries. You may still need to feather the edges down if you do lay it on too thickly though.

goat monkey wrote:

I want to prime an area of plastic to make sure seems and holes were filled and sanded well and texture is consistent.  I've ... finally, i could spray some primer through my airbrush but i'm trying to avoid running anything non-water soluble through it to avoid having to clean the thing.  do i have any other options?  enamel marker maybe?  do they make white sharpies?

Mr. Monkey,

I'd recommend reconsidering the part about using you airbrush for solvent-based paints.  It's no harder to cleanup than acrylics, you just use lacquer thinner.

You might want to try Mr. Surfacer 1000 or 1200 as a combination filler and primer.  The will fill tiny scratches and exposed pits, holes, etc.  Mr Surfacer 500 brushed on will fill small voids.  All three sand to a smooth finish for NMF or gloss coats, as well as flat paints.

Testors makes an acrylic white primer, which is sold under Model Master Acrylics label, but I prefer the Mr. Surfacer.