Continuing on from my weathered builds, I’ve decided to experiment with some chipping medium to see what effect it produces and if it works well with the paints I use. Due to easy local availability, I bought a 35ml jar of Vallejo Chipping Medium.
I took some spare plasticard and cut some small sections for testing. First I put down Alclad grey primer. This is my usual primer and it works very well for me. Next I made up a “rust” paint – a mix of Createx pearl red (as I wanted a bit of metallic feel to the rust), with some Tamiya black to darken it down. I added a little green, yellow and orange just to adjust the colour slightly and thinned the mix with Future Finish and Tamiya acrylic thinner – a combination I know works well with the Createx paints. On top of the rust I sprayed a protective layer of Future Finish and let it dry overnight.
Next I sprayed on the Chipping Medium. It is a thick liquid, but for my first test I wanted to see how it worked straight, without thinner. It went on thick, and left some raised bumps where it dried. That’s an interesting texture, but not what I’m after. I then added some various types of paint to see how they would chip: Createx pearl red, Tamiya yellow, blue, metallic blue, and a grey mix that I made mostly from Createx but thinned with Future Finish and Tamiya Acrylic thinner. Just to be different, a sprayed some of the Tamiya colours over the grey mix as they’re going to look different over grey than brown. Also, the Tamiya blue paints were thinned with their lacquer thinner, which makes the Tamiya colours sprays better and set harder.
The results were interesting. After the top layer of paint was dry I added some water and went rubbing at it with a brush. Soon the paint started to flake off. The Createx pearl red came off very easily. It’s not a strong paint to begin with. The rest took some work, but all reacted well to the chipping medium. I liked how the grey mix worked, and the paints that went on top of the grey mix.
The next experiment is to see if the protective layer of future finish is needed. Again, I primed with the Alclad grey primer and added a layer of the rust. On one side I then coated with Future Finish. This time I’m also trying thinning the Vallejo chipping medium a bit to see if that works better.
Ok, this didn’t work too well…. The side without the layer of Future Finish was way too easy to damage the rust layer.
With the thinned Chipping Medium, the grey mix came off very easily with just a little water and a brush. The Tamiya paints dry quite impervious to water, so they needed the help of a sharper object to start poking away at the paint. But then… it all came off, especially on the yellow.
I don’t like the look of the surface at 1:1. It gets a crackle effect, so if you don’t mind that effect, it’s quite reasonable. We also know it makes for easy chipping as it gives some bumps for the brush to latch onto and pull off the paint. At 1:2 dilution, we now have a smooth finish, but on the tougher paints, it’s hard to chip.
Next to test 3:4 dilution (3 drops of Medium, 4 drops of water). Like the 1:2 dilution it’s going on smooth enough. This is good. Chipping performance is reasonable. The grey mix comes off very easily. If I want heavy chipping, a mix with a Createx base is going to work very well. The Tamiya yellow paint is quite tough. I didn’t let it dry very long – it was basically just touch dry a few minutes after painting and that’s when I began to chip.The blue colours worked reasonably well. They’re tough paints (which is why I like to use the Tamiya lacquer thinner), but the water did make it through to the chipping layer. What I did find is to use a dental pick to just slightly break the surface, and that did work to help guide where the chipping occurred.