Grey Primer 200ml Bottle

You can't go wrong with this primer when working with an airbrush. Straight from the bottle it flowed beautifully through my Badger airbrush. The primer self levels and leaves a great surface for follow-on painting. I would recommend that you allow a full day for the primer to cure. I can assure you it beats the pants off Model Master primer!

This primer is a acrylic primer. That's what the polyurethane means. This means that it's not very durable as it's grip on the plastic is weaker. Acrylic paint will not damage the primer and neither will enamel paints. Lacquers are a bit trickier as too much will melt the primer (and possibly the plastic underneath) and cause the paint to become splotchy. However, if you bump a key or something hard onto the bare primer, it will scratch. It is not very durable at all. This issue is reduced when paint is applied as the top coats will harden and help protect the kit. If you try to sand this primer, then you'll probably fail. Because it gets damaged so easily, the sandpaper will only do that more. The grey primer covers much better than the white primer and is actually smoother. This means that it sprays smoother and is probably thinner, too. Unfortunately, beyond that it's just like the white primer in quality. Which isn't that great... Just go with a Tamiya spray can primer.

Follow the Vallejo directions. It's worth watching the primer video on the Vallejo site. I've been using it at 15 to 18 psi in a Grex airbrush. Remember that it is a polyurethane, and does not achieve full cure for about 24 hours at 68 to 70°F at relative humidity of 50%. Contrary to what another reviewer said, when properly applied and cured it can be wet sanded. Sufficient cure time is critical if you are going to sand it.