Can I spray Acrylic varnish, gloss or matt, over enamels? Are there any gotchas? Thinking water over oil based paints might not mix.
What about Future over Enamels?
If neither of these anyone tried Humbrol enamel varnish gloss or matt. Any good?
You can apply either an enamel over a fully cured acrylic or an acrylic over a fully cured enamel. The key phrase is “fully cured.” Cured is not dry, curing takes much longer, especially for an acrylic. While enamels cure faster, they often outgas longer. As a general rule of thumb, Wait a minimum of 24 full hours before applying one system over the other, especially in cool, humid conditions.
Furthermore, and this is critical: acrylics must be applied to a surface completely free of skin oils, mold release agents, or any other surface contaminants. The best prepainting cleaners for styrene and resin are surfactant cleaners (Simple Green contains surfactants, but must be rinsed). Rinsing must be done with distilled or deionized water. Follow this with an alcohol wipe, either 90+% isopropyl, ethyl, or denatured alcohol. Do not use 70% alcohol for this.
Ross,
How about skipping the Simple Green altogether and just using 91% Iso Alcohol? That is what I do or I use Polly S Plastic Prep which also works well although I am sure that 91% Iso Alcohol probably works just as well and for a lot less money.
Mike,
Just my “belt and suspenders” approach, though there is a good reason, especially with resin parts and some foreign kits. Resin parts tend to bleed plasticizers and other things for a long time, and many manufacturers don’t clean them too well. Some kits made in both Europe and Asia have some truely difficult form release agents still clinging to them, or maybe they bleed plasticizers, too.
It takes so little time to clean the kit surface, and it’s such a pain to strip a paint job or try to “fix” a problem spot.
Thanks Ross. Your expertise is always appreciated my friend. [:D]