Acrylic with enamels

I keep hearing the cautionary phrase, "Acrylics and enamels don't mix."

I always assumed that it would be very unwise to mix them in the bottle. Is there a reason that acrylics cannot be used alongside enamels on the same model? Or, either over-sprayed with the other when suitable dry?

I really want to switch to mostly acrylic, but don't know too much about them.

Thank you in advance,

Don H.

Reply to
Don Harstad
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I can't see any problem if the paint you are overspraying is absolutely cured - but remember that doesn't just mean touch\handle dry, full cure could be days.

The best thing to do is a test yourself.

Not sure how widespread this is, but in the UK (and I think Europe) from Jan

2010 the sale of oil-based paints will be banned, presumably in a bid to save the environment. We have just had a ban on 100W lightbulbs too!

So it looks like I will have to move from the humbrol enamels that I prefer. The trouble I have with acrylics is brush painting. I still haven't moved to spraying (I have an airbrush but have never mastered it). Whilst I find I can brush paint with enamels pretty well I find acrylics (especially Tamiya ones) really difficult.

Cheers,

Nigel

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Reply to
Nigel Heather the-heathers.co.uk>

I tried spraying enamel over acrylic several years ago. It frosted or checkered the acrylic. I found I could use acrylic over well cured enamel. I hesitate to do so, however, since I generally use a lacquer overcoat- either dullcoat or glosscoat. It seems to go over enamel ok, have been afraid to try it over acrylic.

Reply to
Don Stauffer

Correct. They're chemically incompatible. Results would depend on the brands, but it could be like mixing oil & water or milk & vinegar.

You can safely apply acrylic on top of or beside enamel if the enamel is fully cured.

"Fully cured" means letting the paint dry for at least a few days, preferably a week, maybe longer in humid weather. It may feel dry in less than an hour, but it'll continue hardening and shrinking for some time as the remaining solvents slowly evaporate.

You may be able to spray enamel on top of acrylic if the acrylic is fully cured AND you spray very light coats so the enamel will dry quickly. The problem is that the solvents in enamel are stronger than those in acrylic, and will dissolve dried acrylic very quickly, causing problems like paint lifting or cracking.

Reply to
Wayne C. Morris

Simple rule of thumb, apply the "hotter" paints first. I found that out years ago when I found that I could put flying model dope (generally Butyrate Dope back then) on plastic, but not over enamel. I didn't have as much as problem with enamel over the dope (at the time, the dope was the only source for the color that I wanted, a day-glo orange, IIRC). Later I found the same to be true for lacquer -> enamel -> acrylic. As always, test first on scrap plastic and NEVER try to store them in the same bottle.

Reply to
The Old Man

Some good info here.

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Sorry for the earlier post; too much multi-tasking, Curt KVPS

Reply to
Curt

Wayne C. Morris wrote: : : You may be able to spray enamel on top of acrylic if the acrylic : is fully cured AND you spray very light coats so the enamel will : dry quickly. : For applying "filters", I do not have any problems with brushing paint thinner over PolyScale gloss clear.

One of the things I like about PolyScale is that nothing seems to phase it once it has dried.

And, I have applied PolyScale flat clear over the same oil based "filters" without any problems.

Bruce

Reply to
Bruce Burden

Don Harstad wrote: : : I always assumed that it would be very unwise to mix them in the bottle. : Well, I would not suggest ever mixing paint in an original bottle. You can purchase empty bottles easily enough, and mix the concoction in the empty bottle. If the concoction fails, you are out a bit of paint, not the entire bottle or more of the original colors. : : there a reason that acrylics cannot be used alongside enamels on the same : model? Or, either over-sprayed with the other when suitable dry? : I have to disclose the fact that I do not like enamel paints, and a big reason why I don't like them is how long they take to dry to the touch, nevermind cure.

Having said that, there is no reason you can't use acrylics and enamels on a model. The caveat is that the proceeding coat has to have cured.

Acrylics cure very quickly, as a rule (sometimes too quickly), lacquers also tend to cure quickly. Enamels - not so much, in my experience. : : I really want to switch to mostly acrylic, but don't know too much about : them. : As mentioned above, acrylics cure quickly - too quickly, in general. The way to solve that problems is to add some retarder to the base color. 10% or so retarder will help a lot when working with acrylics, either airbrushing or paint brushing.

Also, be prepared to accept that what the color is in the bottle is not necessarily the color you will get when dry. Use the company recommended retarder until you have some experience, then you can try alternative retarders on scrap first.

And, when using water-based acrylics, (as opposed to synthetic acrylics), use distilled water as a thinner, not tap water. You never know what the minerals and chemicals in tap water will do do the paint.

Bruce

Reply to
Bruce Burden

There is a big difference between different acrylic paints, Gunze ( Mr Color) and Tamiya are great for airbrushing but not so good for regular brushing, I find some of the others like Lifecolor and humbrol acrylic better for brushing. There is also quite a difference regards thinning agents. Gunze and tamiya will thin with propenol ( rubbing alcohol ), Metho, GP thinners etc and the others need a bit of Distilled water and Windex. you will need to experiment a bit but hey that's all part of the fun? I think acrylic paints a more colour fast, Humbrol enamel for example can discolour with age quite a bit. ( especially white.) There are quite a few sites with info on the paints but I have used acrylics for years and don't seem to have any problems with them regards Jim "Nigel Heather the-heathers.co.uk>" I can't see any problem if the paint you are overspraying is absolutely

Reply to
JDorsett

I have found that by clear coating the painted surface with Testors Clear lacquers, I tends to prevent the white enamels from discoloring. I did a couple of aircraft in the day that weren't overcoated and the paint and the decals both yellowed a bit. But others that were overcoated didn't turn. Is this some form of oxidation? And does the lacquer seal the surface against it? Damned if I know, but it does seem to work.

Reply to
The Old Man

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