Enamel AND Acrylics together?

[dneid]

Hey, All,
I know I have seen a thread on this topic, but I can't seem to find it now. What are the guidelines for mixed use of enamels and acrylics? I almost always stay with one or the both and rarely ever mix them. But...... when forced, what are the general rules? Acrylics over enamels are ok or vice versa?
Dale

 

[stona]

As a rule of thumb L E A in that order. Lacquer,enamel,acrylic.
Cheers
Steve

 

[meatloaf109]

As long as the previous coat is dry, I have never had problems either way.

 

[stona]

As long as the previous coat is dry, I have never had problems either way.

I have

It can be done in a different order of course. It will depend on many factors,brand of paint etc. I would advise caution.

Steve

 

[Vic Balshaw]

Depending on the paint's it may or may not work. My advice is to trial your needs first on a test model, always allow the paint to fully cure before applying another paint type or colour and let your test sit a few days to see if there is any visible reaction.

It's a game of patience and unfortunately it can sometimes take months for any reaction to be seen, not just from the reaction of chemicals in the paint but also by exposure to air, temperature, light or moister.

 

[mikewint]

Generally speaking, you don't want to apply LACQUERS over ENAMELS. This is because the solvents used in lacquers are MUCH "hotter" (stronger, faster evaporating) than enamel solvents, and the lacquer solvents can 'dissolve' the enamel paint underneath them, leading to "alligatoring" or cracking or other things that TOTALLY ruin the paint finish.

Now, like everything else, there ARE exceptions to the rules... it can be done (sometimes) in VERY VERY THIN, gradual coats, that don't put enough lacquer thinner/paint onto the enamel surface to attack it.

Enamel, having 'softer, slower' solvents, CAN be applied safely over lacquer in most cases.

Paint formulations have gotten SO complex and different between manufacturers that it's hard to say anymore WHAT is compatible with anything else... for example I have heard of problems occuring with new Krylon even being applied over itself even after carefully following can instructions

The main thing to remember is, no matter WHAT you're using... the safest bet to ensure compatibility of the paints is to do a PAINT TEST on scrap tubing or cardboard or something similar to ENSURE that the paint coats will work nicely with each other and not attack each other...

Lastly, ANY lacquer paint or primer is a poor foundation coat to apply anything over it except more lacquer. Lacquers absorb the other paints thinner formulations which eventually turn into gasses UNDER the other paint causing delamination over time

 

[Airframes]

I'll only add that, when testing, apply the coating to the same type of material that it will be applied to on the finished product. If, for example, the material is plastic (which of course is most of the time in our hobby), then test on the same type of plastic, not wood, paper, card, PVC, etc.
The reason may not be immediately obvious, but absorbent materials such as paper or cardboard will produce not only a different finish, but are likely to alter any reaction effects, because the first coat will be at least partially absorbed.
Generally speaking, it's normally OK to apply acrylics over enamels, given that the latter are fully cured. Rule of thumb is that the opposite does not work - however, if applied carefully, and without too much thinner, and in relatively small areas, then enamel can sometimes work over acrylics. BUT - as mentioned elsewhere, test first!

 

[dneid]

Hey, Guys,
Thank you all for the feedback and help. I do appreciate it. I think I just may purchase the colors I need in enamel and avoid any further complications.
Dale

 

[meatloaf109]

I guess I have been lucky! As I have said before, "There I sat, fat, dumb and happy!"

 

[mikewint]

Paul, paints today, in general, have widely divergent formulations so general rules are hard to formula except as Terry said TEST ON SCRAP and also to echo Terry make sure it is the same type of material. As I have said before I'm an acrylic man, water is my solvent. I have a few bottles of enamel in colors I could not find anywhere in arcrlic but that's it
Terry, thanks I did forget to mention that

 

[meatloaf109]

Yep, I actually haven't used enamels for several years now, I just remember painting one over the other years ago. My current airbrush has never had anything but acrylics through it.

 

[mikewint]

Same here, working indoors without a special paint booth it is the only way to paint. A very few can brush finishes to rival spray but not I

 

[N4521U]

Boy, Lacquer over Enamel.....................

Years ago in my sign painting life, I lettered an all steel bodied Model A Ford sedan delivery. It was Ferrari red. The body shop painted red lacquer over enamel primer. It was DRY as a bone. Spent a couple of days painting "the Tobacco Shop" complete with a pipe on it, both sides. Six months later it looked like the old crackle finish pianos. Not good, not good at all. Shop had to strip, prime and paint the whole car, and I had to re-letter it. Finished it at midnight, went to the Oakland Roadster show the next day.

 

[Airframes]

Hmm. If certain Government departments saw that, they'd be bound to use it as further proof that smoking is hazardous .... I'll get me other coat!