Getting back to modeling after many years. I use airbrushing primarily. The question i have is I recently purchased a simple car model 57 Chevrolet Bel Air and cleaned it up to paint the body. I wash parts first. But the problem i seem to have is after putting primer on the car and letting it sit for a week while on a fishing trip. I came home to work on the car. I wanted to paint the car an opaque red over white primer. which I did. now the red paint after sitting for a day or so did not seem to set up as expected. both primer and red were acrylic water base. but the red is not set or hardened. I litely sand the first coat to prepare for the next coat. The paint did not seem quite ready, which i can’t figure. It’s like it’s not hardening. It’s not sticky but it’s not what i call done. i included pictures of the paint bottles but they wont upload
Just name the paint brands used.
Yes, what brand of acrylic paint did you use? And what, if anything did you use to thin the paint for airbrushing?
Us art supply opaque red acrylic
vallejo mcha primer acrylic
I’ve never used the US Art Supply paint, so I can’t comment there. But the Vallejo primer, if it’s anything like Vallejo Model Air, may have a “rubbery” feel once dry, for lack of a better term.
Rubbery was what the red paint felt like
I have never heard of this brand. I googled paint reviews and read the same issues you are having were noted on plastics. That paint may not be suited to go on plastic but on canvass or clothing. I suggest using paints designed for our hobby as in plastic models. As for Vallejo, not a fan of it and would use a better primer that has good adhesion.
What paint do you use?
I did a search on US Art Supply, too, and it sounds like it’s really more of an arts & crafts paint brand.
I use some craft store paints, among other paints, like Americana, Folk Art, and Apple Barrel. They’re all fine for hand-brushing, especially on figures, and for weathering. And they can be airbrushed.
But since they’re formulated more for arts & crafts use than for scale modeling, I don’t recommend them for airbrushing. I found that the pigments are a little more granular than in modeling paint brands. So the finished surfaces can have more of a texture than say Tamiya, or the now-defunct Model Master, MRP, Mr Hobby, and so on.
Are you limited to using water-soluable acrylics, for example, because of the fumes lacquers or enamels give off? Or could you try those? Many car modelers do.
I’m not a fan of Vallejo or any water-based acrylic for airbrushing either. For a primer, I use decanted Tamiya Surface Primer, thinned with MEK for extra bite on the plastic. Gunze has their Mr. Surfacer primer that is already in bottles, and its pretty much the same stuff as far as I can tell. I used to use Mr. Surfacer 1000, also thinned with MEK, and that was an excellent airbrushed primer. For painting a car body, I would recommend an enamel paint like MCW or Model Master (you can still find Model Master enamels, but they don’t make them anymore, so they’re usually pretty costly). Enamels do take a while to fully cure (about a week for a gloss paintjob) and they are a little fragile, but they’re far more durable than most acrylics, and lacquers are great for durability and drying time, but its much more difficult to get a good gloss with those because they dry so quickly.
Not limited to acrylic but i am both by fumes
i did not know you could use mek with acrylic paint. However i have a paint hood with extraction to outside.
MEK and acrylic paint aren’t compatible, so don’t mix those together, it’ll gum up your airbrush. The primers I thin with MEK are both lacquers.
The good thing about both MEK and lacquer-based paints and primers is that, although they all are really smelly, they dry so quickly that the smell doesn’t linger like it does with enamels. You can also keep the fumes to a minimum with your airbrushing technique. Unlike a lot of guys I see making videos on YouTube, I’ve never seen the need for using my airbrush like a firehose and shooting clouds of paint mist. Nearly all of the paint I’m shooting is going on the model and not into the air.
Ditto
I use enamels and lacquers like Mr. Color, Tamiya, Testors, Alclad. As for primers I use Mr. Surfacer, and Tamiya both have superior bonding qualities over acrylics.
My editor messed up i thought you said it could mix with mek and i ment to say i did not know it could mix
I am a fan of Vallejo primers. Used properly, on a clean surface they work quite well, especially under Vallejo paints.
Paint and solvent compatibility is always an issue. Unless you really know your paint chemistry, mixing different types is an experiment waiting to go wrong. It’s not worth ruining an expensive kit or wasting expensive paint.
I was once a coatings chemist, and I don’t experiment on kits. My suggestion is to strip the paint from the model, and only use compatible paints intended for scale modeling.
And if someone wants to experiment, use a “test mule”-an old kit, other scraps of styrene, like lawn signs, milk jugs, plastic spoons, etc, before shooting it on a model.
I have no issue with Vallejo paints. The primer in my book is just OK, but Stynylrez is a big notch up and a very similar type of primer ( acrylic/poly). Both apply nice but Vallejo really is a next day cure type primer, where Stynylrez is ready to go in 30 minutes to an hour. Vallejo is non sanding, Stynylrez sands or scuffs very well. Stynylrez will handle a full blue painters tape pull test ( I’ve conducted this test myself). Stynylrez will accept all acrylics, water borne or alcohol, along with enamels and mild lacquers. If hot lacquer is someones thing then stick with the solvent based lacquer primers . Stynylrez is also a primer/sealer. Not sure if Vallejo primer ticks that box or not.
I’ve been using Stynylrez in the fashion I mention above for 7-8 years now. The only stipulation is if it’s shelved for long periods of time then it needs a good power mixing with something like the Badger battery operated hand held mixer. You will never get it all back together by shaking or with a stick. And never let it freeze, if it freezes it’s over with. Just sayin.
I’ve discovered that very light sanding (≥800 grit), or even polishing with a polishing stick can be used to remove minor defects in Vallejo primer coats.
Somewhere on the Vallejo website I read a recommendation for buffing the primer coat with blotter paper or equivalent. Haven’t tried that, yet.
I used to buff up Stynylrez with 000 steel wool ( it actually made a sheen on it), that may work on the Vallejo primer well, though I haven’t tried it. I should, then I can add it to my 8 year long list of tests of various acrylic paints lol. I have nothing against Vallejo primer personally, I just like Stynylrez better. I know some folks just about hate the stuff but I have no idea if they follow Vallejo’s suggested 24 hour cure time etc.
Anyway, I stopped the steel wool idea on Stynylrez for a couple of reasons. Most of the time it needs nothing. When it needs a scuff micro pads work fine at around 1000- 1500 or so. But I wanted a bit of tooth to the scuff, not a polishing. But with stynylrez you can sand it down to feather it off if you wanted to.