My friend, Krylon Matte Finish for priming

[sargentx]

I did some experimenting this summer in search of the ultimate primer for plastic. I tried Tamiya fine surface, automotive primer, Krylon Fusion for Plastics, and just about any can of aerosol paint that said "Primer" or "for plastic" on it that I could get my hands on. I did multiple scratch tests on styrene to assess and document the various adhesions. In the end, I discovered Krylon Matte Finish. This stuff is so amazing by leaps and bounds beyond anything I tried. In fact, you can't scratch it off! All other brands can't survive a good fingernail scratch. For interest sake, Tamiya Fine Surface fared quite poorly compared to just about everything else and did not have any outstanding "fineness" compared to the others. It was also considerably more stinky and headache inducing for me as well.

Because the Krylon Matte is formulated as a finish for multiple artistic surfaces, it tends to grab onto just about anything. I don't even wash my plastic anymore,! (I do soak my PE lacquer thinner over night to remove the enamel coating) One coat of this and it's bonded for good. Not only that, it leaves a most beautiful toothy surface that just loves receiving airbrush spray and hand painting. You'll find that your subsequent paint layers are also very well bonded. I personally love the grey that most models are moulded in as a base-colour. I simply spray the Krylon Matte on my sub-assemblies before painting and I'm ready to go. It starts things off very nicely for me.
Anyway, definitely give this stuff a go. It's dreamy.

[MareNostrum]

Thanks for this additional tip, I've been using Krylon Fusion for Plastics and have been delighted with it (prefer using the white, but not all that easy to find). Sounds as if the Matte version adds more versatility, will have to pick up a can or two.

[hawkeye3d]

I'll have to hit Crappy Tire and see what they have

Bob

[sargentx]

If you like starting on a white base, just spray your mode with the Krylon Matte, then spray a light, white coat. Should be great!