Is it ok to paint acrylic over dried enamel?

You can generally paint acrylics over (well cured) enamels without any issues at all. The thinners used for acrylics are "softer" and don't usually affect enamels.

In reverse, some acrylics may be reactive to enamel thinners. Tamiya acrylics are not usually affected, Gunze acrylics are. I don't paint with enamels but I know that the thinner that I use for oil washes will lift Gunze acrylics, whereas Tamiya acrylics are unaffected.

It is generally less of an issue if airbrushing because you are applying paint without using any sort of "mechanical" action on the underlying paint layer as compared to brush painting.

Just about any paint can be sprayed over another if done properly.

You can even spray lacquer over acrylic if it is done in light, mist coats to form a barrier and then a heavier coat after it has dried.

MikeV wrote:

Just about any paint can be sprayed over another if done properly. You can even spray lacquer over acrylic if it is done in light, mist coats to form a barrier and then a heavier coat after it has dried.

Ooh Mike... I'm surprised at you!

You didn't specifically say it, but it's implied...

Lacquer over enamel? FOR SHAME

That be a risk I'd rather not take.

jhande wrote:

MikeV wrote: Just about any paint can be sprayed over another if done properly. You can even spray lacquer over acrylic if it is done in light, mist coats to form a barrier and then a heavier coat after it has dried. Ooh Mike... I'm surprised at you! You didn't specifically say it, but it's implied... Lacquer over enamel? FOR SHAME That be a risk I'd rather not take.

Chicken? lol 

It can be done and you know it. Isn't Testors Dullcoat a lacquer? People spray it over enamels all the time and have been for years. 

MikeV wrote:

jhande wrote:  MikeV wrote: Just about any paint can be sprayed over another if done properly. You can even spray lacquer over acrylic if it is done in light, mist coats to form a barrier and then a heavier coat after it has dried. Ooh Mike... I'm surprised at you! You didn't specifically say it, but it's implied... Lacquer over enamel? FOR SHAME That be a risk I'd rather not take. Chicken? lol  It can be done and you know it. Isn't Testors Dullcoat a lacquer? People spray it over enamels all the time and have been for years.

You're right on, Mike.  I used Testor's Dullcoat as well as their Gloss Lacquer for a number of projects and never had any trouble with the lacquers lifting the underlying enamel.  I think it is just a matter of going light on the coverage.

Andy

Cluck, cluck, cluck... oop's my feathers are showing.

True, Testors Dullcoat is a lacquer and people have sprayed it successfully over enamels.

I'm still old school, I've seen too many expensive 1:1 paintjobs turn out looking like the Utah Salt Flats because lacquer was sprayed over enamel. Even enamel paintjobs that were 5+ years old.

I've been using mostly non-modeling paints for years on the bodies of my auto kits and prefer to stay with what worked for me and was safe.

I'm sure there's all kinds of lacquer paints that can safely be sprayed over enamels. But with my luck I'll use one that isn't. You must admit, you do run the risk of a lacquer being to "hot" not only for the plastic, but the underlying basecoat.

I didn't mean to pick on you Mike, was just joking.

I only intended to add a word of caution.
Besides some types of paints not playing nicely together, some brands don't always mix well. Oop's, there I go again, thinking outside the modeling products.

Y E S

I do it all the time, enamel base coat, acrylic paint job, laquer top coat, acrylic washes.

jhande wrote:

Cluck, cluck, cluck... oop's my feathers are showing. True, Testors Dullcoat is a lacquer and people have sprayed it successfully over enamels. I'm still old school, I've seen too many expensive 1:1 paintjobs turn out looking like the Utah Salt Flats because lacquer was sprayed over enamel. Even enamel paintjobs that were 5+ years old. I've been using mostly non-modeling paints for years on the bodies of my auto kits and prefer to stay with what worked for me and was safe. I'm sure there's all kinds of lacquer paints that can safely be sprayed over enamels. But with my luck I'll use one that isn't. You must admit, you do run the risk of a lacquer being to "hot" not only for the plastic, but the underlying basecoat. I didn't mean to pick on you Mike, was just joking. I only intended to add a word of caution. Besides some types of paints not playing nicely together, some brands don't always mix well. Oop's, there I go again, thinking outside the modeling products.

Thanks Jim and I didn't think you were picking on me.

Good advice. 

MikeV wrote:

Thanks Jim and I didn't think you were picking on me.

Cool

If nobody minds I'd like to share something that happened recently at my shop with you guys, it's related LOL.

A young guy (late 20's) came into my shop looking to get back into the hobby. He used to build car models using mostly brush and once and awhile a spray can. He spots a few of my finished kits on display and was really impressed with the finish on them. I pointed out which ones were done with spray cans and which with my AB. He asked me how I got them looking so good because he never could. I explained to him my steps, even wrote them down for him. He picked up a kit, some bottle enamel paints, a spray can, cement, a few brushes, etc...

A few weeks later he comes back in carrying a brown paper bag. Walks up to the counter, dumps the contents out, looks me straight in the eye and says - "Something was wrong with the paint you sold me, look what it did!" I couldn't believe my eyes... the body was painted but crackled and starting to lift. Some spots looked as if he attacked it with a blow torch. Some other parts also looked shiny and melted. Hummm... I knew right away but I had to ask - "What did you do to make the parts shiny?" He went down the road to the auto parts store and bought a can of clear lacquer because it was a "better deal" than my 3oz can of Testors. Not once did I mention to him that I use any kind of clear coat. All I do is color sand and rub out before waxing.

I told him I would gladly replace the kit if the Testors paint did that to his kit. But first he would have to do one thing for me, bring in the can of lacquer. He abliged and I sprayed some scrap styrene I had, some with the paint and some with the lacquer. After a short period of time he stood there watching the lacquered parts starting to get soft and distort while the painted parts remained fine. Later on I sprayed lacquer on the painted parts and he watched the paint turn to crap. He realized it was the lacquer and not the paint. I told him it was not designed for plastic or going over enamel. It was an automotive product intended for lacquer over metal.

Even though he confessed on trying to take a short cut from the sanding and rubbing and agreed it was the lacquer, I replaced his kit anyways after he promissed to by the Testors clear. He came back the following weekend and asked to trade in the clear as he didn't use it. He followed my steps of sanding and rubbing. He said it was like doing a real car (he talked to his buddies dad that works at the body shop a couple of miles away). I refunded his money and he bought a few more kits, paints, etc...

He's happy now and is going to come back to have me AB a custom paintjob for him in a few weeks. He's already making the AB setup list. Cha ching

Sorry for the essay

Happy Modeling

jhande wrote:

MikeV wrote: Thanks Jim and I didn't think you were picking on me. Cool If nobody minds I'd like to share something that happened recently at my shop with you guys, it's related LOL. A young guy (late 20's) came into my shop looking to get back into the hobby. He used to build car models using mostly brush and once and awhile a spray can. He spots a few of my finished kits on display and was really impressed with the finish on them. I pointed out which ones were done with spray cans and which with my AB. He asked me how I got them looking so good because he never could. I explained to him my steps, even wrote them down for him. He picked up a kit, some bottle enamel paints, a spray can, cement, a few brushes, etc... A few weeks later he comes back in carrying a brown paper bag. Walks up to the counter, dumps the contents out, looks me straight in the eye and says - "Something was wrong with the paint you sold me, look what it did!" I couldn't believe my eyes... the body was painted but crackled and starting to lift. Some spots looked as if he attacked it with a blow torch. Some other parts also looked shiny and melted. Hummm... I knew right away but I had to ask - "What did you do to make the parts shiny?" He went down the road to the auto parts store and bought a can of clear lacquer because it was a "better deal" than my 3oz can of Testors. Not once did I mention to him that I use any kind of clear coat. All I do is color sand and rub out before waxing. I told him I would gladly replace the kit if the Testors paint did that to his kit. But first he would have to do one thing for me, bring in the can of lacquer. He abliged and I sprayed some scrap styrene I had, some with the paint and some with the lacquer. After a short period of time he stood there watching the lacquered parts starting to get soft and distort while the painted parts remained fine. Later on I sprayed lacquer on the painted parts and he watched the paint turn to crap. He realized it was the lacquer and not the paint. I told him it was not designed for plastic or going over enamel. It was an automotive product intended for lacquer over metal. Even though he confessed on trying to take a short cut from the sanding and rubbing and agreed it was the lacquer, I replaced his kit anyways after he promissed to by the Testors clear. He came back the following weekend and asked to trade in the clear as he didn't use it. He followed my steps of sanding and rubbing. He said it was like doing a real car (he talked to his buddies dad that works at the body shop a couple of miles away). I refunded his money and he bought a few more kits, paints, etc... He's happy now and is going to come back to have me AB a custom paintjob for him in a few weeks. He's already making the AB setup list. Cha ching Sorry for the essay Happy Modeling

Thanks for the story Jim.

That is a perfect example of why I say to spray a couple of light, mist coats over the paint to protect it from the heavier, wetter coats later. Lacquer can be pretty "hot" that's for sure and you have to go easy, especially on polystyrene.

MikeV wrote:

Thanks for the story Jim. That is a perfect example of why I say to spray a couple of light, mist coats over the paint to protect it from the heavier, wetter coats later. Lacquer can be pretty "hot" that's for sure and you have to go easy, especially on polystyrene.

You are welcome Mike.

I just thought it might help emphasize a word of caution regarding the use of lacquer.

I understand why you mention a couple of light mist coats first. But I also know one persons idea of a light coat might not be the same LOL.

Acrylic and enamel play safe with each other.
Anything over lacquer is safe.
Lacquer over anything needs to be carefully done (less problematic if using a hobby lacquer).