Drying Enamels -basic question-

Good advice from Scott.

- enamels will 'cure' and the solvents continue to evaportate for a while. If you put something overtop of them, the 'curing' may harm the top layer. That doesn't mean it *can't* be done, because I've done it and had no problem. Your best success would be if the paint was very thin, and airbrushed. If it was a really special project, I likely wouldn't risk it and let the underlying coat fully cure.

- primer will provide better paint adhesion, but it will also provide a more solid/uniform base for your top colors. This would be more noticeable if you had lots of putty/body work on the plastic, and if your using a light paint color. There would be a higher chance that you'd see the body work through the paint. Personally, I use primer on almost everything.

Murray

QUOTE: This is a simple forum question(s): Is it advisable to paint over a coat of undried(not dripping wet but semi-wet) enamels, or should I wait until the enamles have cured(overnight)?

The "Best" way is to let them sit overnight, or better yet about 24 hours. The longer they have to cure the better. I've painted over them a lot sooner than that, but I don't like to.

QUOTE: Will primer make a big difference in the final appearance of the model? Are the differences between models with and without primer noticable?

Depends on the primer. True primers (as opposed to just using another color of the same typr of paint) are usually very "Hot" so they dry pretty quickly, leave a flat finish, and also have very fine pigments so that they don't cover up much detail. I've had very good luck with Tamiya primers.

Primers provide a good bonding surface for the top coats, especially acrylics. They also allow you to see flaws in the surface very readily.

In some cases the color of the primer will affect the final color of the top coat. Some "Opaque" paints are not always completely opaque. Yellow is frequently that way. A dark color underneath yellow will frequently give it a darker appearance than a light color underneath. Translucent and some "Metallic" colors are very dependant on the color of the primer underneath. Spray something like "Candy Apple Red" over gold and silver and you get completely different final colors.

I like primers primarily for two reasons:

1) I use mostly acrylic paints and a coat of enamel primer beforehand makes them adhere much better.

2) I can see flaws in the surface before my final color coat. Things that looked great before a coat of primer sometimes look nasty afterwards