Can you use acrylic paints over an enamel primer undercoat? Yes, you can. Here’s what you need to know to do it successfully.
Over the years, I’ve painted a LOT of figures, miniatures and models. Whether it’s an Airfix / Tamiya scale aircraft or tank, Warhammer minis (40k are my favourite) or buildings for model railways, I’ve painted them.
In fact, I’ve always got at least one building or miniature on the go, in some state of construction or modification. I dread to think how many models have passed through my hands and I forever seem to be answering questions from friends, family and Facebook contacts about one technique or another.
And one question that keeps coming up is can acrylic paints be used over enamel primers?
Before answering this it’s worth first touching on why you’d even want or need to do this.
The answer lies in why we use primers and the different behaviours of the two types of paint.
Why use primers
Primers are used for a foundation layer that gives subsequent coats of paint a surface to which they can bond more easily.
Priming also shows up blemishes in the figure that can be corrected before you get too far into the painting process.
And why enamel?
Acrylic is great for model and figure painting, there are more colour choices, its easier to work with and clean afterwards and, of course, it dries quicker than enamel and oils.
However, acrylic doesn’t adhere well to the injection-molded polystyrene that most kits are made with. Enamel is much better at this. It bonds well to plastic and then provides a better base for subsequent painting.
As a result, I always use primers and because, as said, enamel takes to the raw material better I’ve always used it it for my primers. Most of the models you see on ModelRailwayEngineer start life with them.
(Don’t bother with acrylic primers. They maybe cheaper but they don’t work).
From this you can probably guess the answer to the original question.
Once an enamel primer has dried, acrylic paints will adhere to it well and give a strong lasting finish.
With this combination you get an enamel undercast that grips the plastic and a great range of colour and easier to work with top coats.
In my experience, the most important step in getting good results is to clean the plastic first (warm soapy water and scrub with a toothbrush) and then use enamel primer in aerosol form.
Personally, I — along with most experienced modellers — swear by P3, Citadel (Games Workshop/Warhammer), Testors and Tamiya primers. These rattle cans produce a fine mist spray that don’t fine swamp the details of your model. I’ve had better results from them than those the cheap and plentiful car primers some use. The Citadel, Testors and Tamiya brands produce just the right finish, not too smooth so that subsequent coats of Acrylic can’t grip to but smooth enough so as not to add texture to the finish.
How to do it successfully
Shake the can vigorously, hold it approx 10cm away from the model (less for Citadel sprays, more for Tamiya – experiment to find what works for you) and spray on medium humidity days and not super dry. Give it a couple of coats with about 15 mins between each coat, then leave to dry. Modern spray primers will dry quickly but I always give it 24 hours to be sure. Painting before the enamel primer has dried is the cause of most problems I have when applying acrylic to enamel.
Lastly, make sure you do it in a well ventilated space or in a spray both and wear a mask.
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