Hi!

I sat down a while ago and airbrushed some models. After a while I realizes that the paint would very easily rub off if I touched the model with my fingers.

Is this normal? Does the paint take a while to cure or is something wrong with my paint?

Im using Badger acrylics with Vallejos thinner.

I'm very new to the terrifying world of airbrushing and I haven't really had this experience back when I was "brush brushing".

All paint needs to cure. Dry to the touch doesn't mean it has cured yet. Acrylics are also very easy to rub off when fresh, especially if there isn't a decent primer for them to stick to. Do your painting, set the model aside and let it cure overnight before handling and doing any weathering or clear coats.

Kimmo

Enamels are pretty forgiving, but acrylics can lose their adhesion if the model was not washed before painting. Mainly, this is to remove any mold release residue from the plastic, though oil from your skin can also be an issue. Use a bit of dish washing liquid and water, rinse with clear water, and let the model air dry. In some cases, a primer coat may also help.

Doesnt sound normal to me...
I use decanted automotive primer and vallejo model color thinned with vallejo airbrush thinner and the paint wont ruboff.
Have you used primer or do you paint directly to the plastic? If no primer I would test to some scrap if it helps to hold the paint better.
If primer is used does it ruboff or just the base coat?
(I know vallejo primer can do that)
Also make sure the model is clean as said before me.

I'm not too familiar with badger acrylics but I use their stynylrez primers and those are pretty strong. Here's a few things I've noticed that could help you

1. Acrylics don't have the same strength from brand to brand. I think that tamiya and gunze aqueous are weaker than vallejo's when you don't put enough layers.

2. Just because it looks covered doesn't mean that it has a good layer of paint. This is very evident in painting white versus dark colors. You'll notice that if the model is primed, it takes a lot of coats to get white to the color it has to end up with but dark colors seem like a few passes covers fast. Always make sure that there is a good 2-3 layers of paint for dark colors.

3. As most mentioned. Primer helps... a lot

Thanks everyone for your great replies!

The primer did actually stay on. I had washed it with wasing-up liquid and then sprayed it with Vallejo Polyurethane Primer Black and let it dry for about 36 hours. So the primer did stay on. I also tried handling the models as little as possible with my hands.

However, the basecoat for the miniature was Badger Minitaire Charred Stone, which is a really dark grey. After a few passes over the black undercoat it looked good and I moved on to highlights. Maybe the issue is that I made a basecoat that was too thin?

I can, however, think of many occasions where you'd want a thin layer of paint. Such as when making highlights and want some of the basecoat to shine through. What should you do then?

I would do a test to some scrap to see if its a problem with the paint/color/primer.
If those paints arent up to the task I would change brand.

Perhaps Badger acrylics get affected by Vallejo thinner... just a possibility to explore.

it might be better to use Badger acrylic with its dedicated thinner if there is any. Also using a thicker mixture with proportionally more resin carrier in the paint could improve adhesion.

A little heating with a hairdrier can also help, speeding up and improving the hardening process of the acrylic resin at the same time.

This is becoming more and more of a mystery.

I tried again this morning to rub off paint from a miniature that has stood on my desk for 36 hours. The paint came off fairly easily. Since it's a wargaming model it might very well be handled a bit so I don't want the paint to come off too easily.

Maybe I should try to use a hairdrier on the model since my house is quite cold, about 64F/18C.

What is your experience with the durability of airbrushed paint?

I think I found the culprit:
As an experiment I primed another marine and sprayed it with a Vallejo paint instead of a Badger paint. After letting it dry for a couple of hours I took one model painted with Badger paint and one painted with Vallejo paint and rubbed them with my thumb. The Badger mini had a rubbery feel to it and the paint came off quite easily while the Vallejo mini had a harder, smoother surface with much less friction and higher durability.

So I guess I'll stick with Vallejo in the future.

What I do when I'm impatient is let the paint dry a bit and just blast it with vallejo varnish. This helps give a stronger finish to tamiya and gunze paints.

I actually experimented a bit with varnish which I applied with a regular paintbrush. The Badger paint was dissolved by the varnish.

ok now that is strange ...

When you airbrush varnish it dries quickly and only the varnish touches the surface. Brush painting it on is a much thicker coat and can not only dissolve the base paint, but also brush it off at the same time.