Airbrush modellers talked a lot about the need to prime your models before you start painting. So I did this simple test: two plastic spoons were primed with Vallejo Surface Primer black (left and right); the difference is the dilution with airbrush thinner. The left spoon 50 primer/50 thinner, while the one on the right 60 primer / 40 thinner.

Priming the Test Spoons

The brown spoon was not primed and was airbrushed with Vallejo Model Air hull red.

Primed spoons

“Scratch my Back” Test

One of the primed spoons – the 60/40 one was sprayed with Vallejo hull red and left to dry for 12 hours. A scratch test with the rough end of another spoon and fingernails was made. The acrylic paint on unprimed spoon came off.

Conclusion: ALWAYS PRIME YOUR SPOONS, or MODELS!

I use Vallejo Surface primers as these can be diluted with their airbrush thinner.

AVOID AK Interactive Xtreme Metal Primers and Microfillers as these are enamel-based, emit strong turpentine smell and requires special enamel thinner! These are not for acrylic paints. Instead, there are primers made for their acrylic paints. It is recommended to use the thinners from the same paint manufacturers as both primers and paints are developed to work optimallly with each other.

What if you want to preserve the original paint on the model and not overcoat with colored primers? Surprisingly, only AMMO by MIg has One Shot Transparent Primer (Art. No. A.MIG-2041). Alternatively, use gloss or satin acrylic varnish as primer.