Enamel

I've used Model Master enamels over Tamiya acrylics for a while now, and have not had any problems. True, the paint has to cure, but I find that an hour or two is way more than enough time for the acrylic to dry. It's one of the advantages of acrylics...

You are right, this is interesting!

Could have been your primer, I guess, but presumably you had used it before. I've had very good luck with Tamiya primer, as I mentioned, and I don't do anything special. Spray it, let it dry a couple of hours, do whatever I want to on top of it.

That primer is very "Hot" though, so it cures (or at least "Dries") pretty quickly. I usually spray it outside, and by the time I get back to my bench I can see it drying to the touch. A couple of hours in front of a fan seems to be all it takes.

This is VERY interesting, Scott...! My most horrific moment was when I 'primed' an Airbus A300 in white, then airbrushed the top half of the fuselage with Tamiya purple to give it a Federal Express guise (old colour scheme). Looked wonderful for about one day when the purple started to crack, revealing the while...

I've never had problems ever since I used (automotive) Acrylic primers... I throw anything on it and it does not move!

QUOTE: Originally posted by djmodels1999 MusicCity, funnily enough, I'd have said exactly the opposite... I've had troubles (paint crackling in particular) using acrylics over enamels. I use acrylic primer on all my models and then spray them with enamels without any troubles at all... Enamels take much longer to cure and I'd only apply acrylics over enamel if the later was thouroughly dry.

We use the exact opposite procedures

Probably 99% of what I paint now is acrylic, except for enamel primer. I frequently spray parts with enamel primer (specifically Tamiya primer), sit them in front of a fan for a couple of hours, and then paint acrylic over the top. Haven't had any problems with cracking so far.

Just goes to show that none of our "Rules" are carved in stone!

MusicCity, funnily enough, I'd have said exactly the opposite... I've had troubles (paint crackling in particular) using acrylics over enamels. I use acrylic primer on all my models and then spray them with enamels without any troubles at all...

Enamels take much longer to cure and I'd only apply acrylics over enamel if the later was thouroughly dry.

I always use an acrylic car paint primer (comes in spray cans & is meant for painting plastic parts on cars such as door mirror housings etc) It's cheap, easy to use & rubs down smoothly, it also fills some imperfections nicely & shows up others.
Onto that I usually brush paint thinned enamels (Humbrol) & can honestly say that I've never had a reaction problem between the two.
I thin the enamel down by about 30%, it means a quicker drying time & no brushmarks.
Pete

I used to use Enamials, but I just completely got rid of them. I now use Acrylics exclusivly and never use enamials because of their health risk. Everything has a health risk in modeling, I just decided to lighten the load. Ive never had a problem with Acyrlics and Enamials together when I used to use enamials, but I sealed the oppisite paint off before I added the other, so maybe that was what saved it.

I have not had good luck applying enamel over acrylic. I've heard that if the acrylic is allowed to cure thoroughly (as in several days) then you can paint enamel over it, but I have not been able to do that. The enamel always appears to dissolve the acrylic when I try it. A coat of Future over the acrylic may help, don't know if I've tried that or not.

You can, however, paint acrylic over enamel without any problems. The acrylic won't bother the enamel at all.

Enamel is easier to brush paint than acrylic because it doesn't dry nearly as fast. You should have proper ventilation in the area, especially if you are spraying it, because the vapors in enamel thinner can be harmful and you should avoid excessive exposure. I always use a respirator when I spray enamels (I should when I spray acrylic, but I don't always).