Primer is always a good idea. Most paints are made to use the "tooth" of primer to really hold onto the surface.
On vinyl tracks, primer is probably absolutely necessary. And don't wiggle 'em around too much after you've painted them.
There's a flexible body primer, for flexible auto body parts available, sometimes at WalMart. It's clear & in a spray can, that you prime a flexible plastic part, like vinyl & then paint it using whatever finish paint you want & the paint flexes, not flakes. I've used it on vinyl & polypropolene (milk jug) plastic & used any paint I've had over it with great results.
Wash the vinyl tracks in warm soapy water , and let them dry apply a coat of future, them paint them . Never tried this , but remember reading it as a tip on a website somewhere.
I'm painting some vinyl tracks for a tank. Is primer really necessary under the acrylic paint I'll be using? Also, is primer necessary on bare styrene under acrylics? FWIW, I use Testors acryls.
I've not painted any vinyl tracks (not an armor builder as a rule) but I don't use a primer under PollyScale or Model Master acrylic. Just be sure the model styrene is clean before you use any paint on it, even primer.
MB
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