Im currently building the Tamiya RX7 R1 model ( i love RX7s, ive got 2 on the drive :)) but i ran into a problem. When spraypainting the shell with a red rattle can (official tamiya paint) the shell came out terrible. The paint had gone all blotchy and in some areas has just completely gone, it was like some parts of the car had been covered in wax before spraying and as such the paint hadnt stuck to it, but i had THOROUGHLY washed the shell before i sprayed it!
Ive bought another model jsut for the shell itself, i dont want to mess this one up. What steps do i need to take regarding prepping it to get a good finish?
The problem may be the paint, but I doubt it. Washing the model first is a good idea, but only if you do it properly. What did you wash it with? Many dishwashing soaps contain additives and oils designed to moisturize the washers hands and will leave residue on the styrene. Palmolive is a great example of that (you’re soaking in it!). I wash my models with Dawn brand and always wipe down the larger area with isopropyl alcohol to remove any chance of soap residue. Windex with ammonia will also work as Windex is 30% isopropyl alcohol.
Brake fluid or Easy Off will remove the paint from the shell without damaging it. There was no need for the second model, it can be salvaged. However since you have two in the driveway, you might want two on the mantel. Good luck with the repaint!
Oh yeah…
[#welcome] to the forums! Pull up a keyboard and stay a while.
Bill has it—most commercial detergents have some sort of skin conditioner, or they have something to prevent water spots, or they just have a formulation that leaves something more or less innocuous on the surface. It only takes traces. Simple Green, Formula 409, and Windex all work well. All should be rinsed with water, followed by an alcohol (isopropyl or ethyl or denatured) wipe.
If you have to wash the model between coats, I suggest Woollite, followed by a distilled or deionized water rinse. If you are using enamels, this can be followed by an alcohol wipe. If using acrylics, do not use alcohol on the painted surface.
and [#welcome]
[#offtopic]
Bill, nice to see you posting again! [#welcome]
More [#offtopic] Hi Ross! I’ve been pretty busy with the new job, lurking but not doing too much posting. <now back to our regular programming!>
I’ll have to give the Woolite treatment a try. I have a few models that I’ve put aside after painting a portion (Darn modeling ADHD!) and are now covered in dust!
Another thing to try is just a touch—a few grams or a teaspoon to a tablespoon—of Calgon in the wash water. While it is intended to cure hard water problems, it is a marvelous deflocculant ($10.50 word for anti-clumping agent) for anything. We used to use it in clay minerology to help keep the clay dispersed.