So I sprayed fingernail polish for the first time,what went wrong?!

[dantewallace]

I bought two bottles of nail polish that I really like and decided to spray them yesterday. I followed Dr CRanky's tutorial on youtube before the attempt so I knew what I was getting into beforehand. I diluted one bottle 1:1 with lacquer thinner and sprayed at 25 PSI. As I began to spray everything was going smoothly ,but then I started to get a strange surface on the body. A sandy build up of some sort that now has a sandpaper texture. Any clue as to what went wrong? I was able to lightly wet sand the surface and smooth everything back out,but who's to say that this won't happen again?

[ScaleDale]

What type of nail polish? Anything metallic?

A surface like that often comes from paint that is almost dry when it hits the surface of the model and builds up in micro clumps like sandpaper. Lacquer thinner evaporates quickly and a 1:1 mix might do that. Maybe try lower PSI and spray closer to the body. Also, since you said it started out OK, maybe stop and do a bunch of very light coats.

Dale

[Ace-Garageguy]

What type of nail polish? Anything metallic?

A surface like that often comes from paint that is almost dry when it hits the surface of the model and builds up in micro clumps like sandpaper. Lacquer thinner evaporates quickly and a 1:1 mix might do that. Maybe try lower PSI and spray closer to the body. Also, since you said it started out OK, maybe stop and do a bunch of very light coats.

Dale

Exactly. A rough "sandpaper" finish is almost invariably caused by 1) shooting the paint too dry and 2) shooting it too far from the body, allowing the thinner to flash out before it hits the model.

For the bazillionth time, THIS IS WHY IT'S IMPERATIVE TO TEST on a junk body BEFORE YOU PAINT A MODEL YOU CARE ABOUT, whenever you try new materials or techniques !!!

There is also the POSSIBILITY that lacquer thinner isn't compatible with the particular nail-polish you're using, and again, TESTING beforehand will show up potential problems and save you a ton of work correcting un-necessary screwups.

[Art Anderson]

"Ace" and Dale have it very right: Either the nail polish was too thick in consistency from the outset, or it was incompatible with the the thinner you used.

Let's take a look at "consistency"; this is a "measure" (if you will) of how thick or thin the nail polish appeared in your airbrush jar after you added thinner to it. There can be one real problem, with enamels, water-borne acrylics, and certainly lacquers--including fingernail polish: Two bottles of the same paint may, or may not (!) be the exact same consistency--that can happen for any number of reasons that are not important here. Being as I am not an engineer, nor is my college degree in any of the physical sciences, and I know just enough math to get me into trouble--I don't use set formula's to thin paint by. OK, so a little observation here: Properly thinned lacquer (and almost all nail polish is a lacquer of one kind or another), when in a glass jar, such as your airbrush jar, will "sheet" down the side of the glass container, very much like 2% milk "sheets" down the inside surface of the glass as you drink it. Many of us have found that thinning lacquers to the point that when in the airbrush jar, if you turn the jar at an angle and then hold it straight up and down, the lacquer will "sheet" as it drains down the inner surface of the jar very close to the way 2% milk does, and the effect you see is very much like that. Given the possibility that different bottles of lacquers may well not be the same consistency (one could be thinner than the others, or thicker!), this becomes an "eyeball" sort of thing. If you get the lacquer too thin, that's not a problem, it just means that you will have to compensate by laying on lighter, thinner coats to avoid runs or sags.

Second, and this relates to the consistency of your thinned lacquer--if the lacquer is properly thinned as I've laid out above (and BTW, if you spray rattle can lacquer into your airbrush jar, it will behave very much like 2% milk in a glass tumbler--that makes rattle can paint, decanted, a very good example of well thinned enamels or lacquers.

You could, as Ace suggested, have a problem with the thinner you used being compatible with the nail polish (given that you say that the "sand-finish" started AFTER you had laid on some nail polish, leads me to wonder if that isn't the cause. To test for this, mix up a little bit of nail polish with your thinner in your color jar, then close it up tight, and allow it to sit for perhaps 15 minutes or so. If the thinner is not compatible, it should make the nail polish "curdle" like sour milk. If that is the problem, then you will need to get some different lacquer thinner. I'm using Kleen Strip medium temperature lacquer thinner that I got in the paint department at Walmart and that stuff has worked for me, with acrylic lacquer (IIRC, fingernail polish almost all the time is an acrylic lacquer), Testors enamels, Humbrol enamels, and even a bit of automotive acrylic lacquer.

Last, if the problem is not the nail polish reacting with the thinner, even with ensuring that your nail polish is thinned out enough, you might try reducing the PSI on your airbrush, which will allow you to move in closer to the work (I do most of my airbrushing, be that body colors, or chassis-engne-interior parts, at less then 2" from the work, often as close as an inch!), and learn to move the airbrush more slowly, allowing the sprayed coats to be "wet" or shiny.

Hope this helps! I know it has worked for me for a whole lot of years.

Art

[dantewallace]

What type of nail polish? Anything metallic?

A surface like that often comes from paint that is almost dry when it hits the surface of the model and builds up in micro clumps like sandpaper. Lacquer thinner evaporates quickly and a 1:1 mix might do that. Maybe try lower PSI and spray closer to the body. Also, since you said it started out OK, maybe stop and do a bunch of very light coats.

Dale

Sorry for late reply guys!! I forgot to subscribe to my own thread lol.

The polish was pearlescent. I found nothing on the bottle stating what type of polish it was ,but I assumed that like most it was a lacquer.

[dantewallace]

Exactly. A rough "sandpaper" finish is almost invariably caused by 1) shooting the paint too dry and 2) shooting it too far from the body, allowing the thinner to flash out before it hits the model.

For the bazillionth time, THIS IS WHY IT'S IMPERATIVE TO TEST on a junk body BEFORE YOU PAINT A MODEL YOU CARE ABOUT, whenever you try new materials or techniques !!!

There is also the POSSIBILITY that lacquer thinner isn't compatible with the particular nail-polish you're using, and again, TESTING beforehand will show up potential problems and save you a ton of work correcting un-necessary screwups.

Yes I understand test before spray. The body was being used as a test mule that I do not care about. It just doesn't seem right that the paint sprayed flawlessly onto all of the smaller parts but not the body. All parts were sprayed at the same distance as done with all of my previous builds

Edited August 26, 2013 by dantewallace

[dantewallace]

"Ace" and Dale have it very right: Either the nail polish was too thick in consistency from the outset, or it was incompatible with the the thinner you used.

Let's take a look at "consistency"; this is a "measure" (if you will) of how thick or thin the nail polish appeared in your airbrush jar after you added thinner to it. There can be one real problem, with enamels, water-borne acrylics, and certainly lacquers--including fingernail polish: Two bottles of the same paint may, or may not (!) be the exact same consistency--that can happen for any number of reasons that are not important here. Being as I am not an engineer, nor is my college degree in any of the physical sciences, and I know just enough math to get me into trouble--I don't use set formula's to thin paint by. OK, so a little observation here: Properly thinned lacquer (and almost all nail polish is a lacquer of one kind or another), when in a glass jar, such as your airbrush jar, will "sheet" down the side of the glass container, very much like 2% milk "sheets" down the inside surface of the glass as you drink it. Many of us have found that thinning lacquers to the point that when in the airbrush jar, if you turn the jar at an angle and then hold it straight up and down, the lacquer will "sheet" as it drains down the inner surface of the jar very close to the way 2% milk does, and the effect you see is very much like that. Given the possibility that different bottles of lacquers may well not be the same consistency (one could be thinner than the others, or thicker!), this becomes an "eyeball" sort of thing. If you get the lacquer too thin, that's not a problem, it just means that you will have to compensate by laying on lighter, thinner coats to avoid runs or sags.

Second, and this relates to the consistency of your thinned lacquer--if the lacquer is properly thinned as I've laid out above (and BTW, if you spray rattle can lacquer into your airbrush jar, it will behave very much like 2% milk in a glass tumbler--that makes rattle can paint, decanted, a very good example of well thinned enamels or lacquers.

You could, as Ace suggested, have a problem with the thinner you used being compatible with the nail polish (given that you say that the "sand-finish" started AFTER you had laid on some nail polish, leads me to wonder if that isn't the cause. To test for this, mix up a little bit of nail polish with your thinner in your color jar, then close it up tight, and allow it to sit for perhaps 15 minutes or so. If the thinner is not compatible, it should make the nail polish "curdle" like sour milk. If that is the problem, then you will need to get some different lacquer thinner. I'm using Kleen Strip medium temperature lacquer thinner that I got in the paint department at Walmart and that stuff has worked for me, with acrylic lacquer (IIRC, fingernail polish almost all the time is an acrylic lacquer), Testors enamels, Humbrol enamels, and even a bit of automotive acrylic lacquer.

Last, if the problem is not the nail polish reacting with the thinner, even with ensuring that your nail polish is thinned out enough, you might try reducing the PSI on your airbrush, which will allow you to move in closer to the work (I do most of my airbrushing, be that body colors, or chassis-engne-interior parts, at less then 2" from the work, often as close as an inch!), and learn to move the airbrush more slowly, allowing the sprayed coats to be "wet" or shiny.

Hope this helps! I know it has worked for me for a whole lot of years.

Art

I use the 2% milk consistency on every occasion of airbrushing no matter what type of paint I use. I made a mistake in what I said making you think that I meant the sand like finish started "after " I sprayed, I apologise for the misunderstanding. This surface was actually occurring as I was spraying. What you guys are saying about spray distance sounds exactly right and makes total sense about the paint drying as its hitting the surface. Now that I think about it, I did spray the side view mirrors at about half an inch away and they came out great. The body and the rest of the parts were spray maybe 3-4 inches away. This comes from habit of using rattlecan and regular lacquer/enamel based model paints in my airbrush. I always spray at a distance using multiple light mist passes to prevent runs and sagging. I attempted to do the same with the polish I get what you guys are saying though, with nail polish it has to be sprayed up close leaving a wet finish when using hot thinner. Am I correct in saying this?

[Art Anderson]

Dante,

I spray at 2" or less with my Passche H airbrush, no matter the paint I'm using, be it lacquer, enamel, or waterborne acrylic. 3-4 inches out, unless you had your airbrush really opened up, would account for your "sand finish", or so it seems to me. Still though, you might test to see if the thinner you used is curdling the paint--you should see that in the color jar.

Art

[LokisTyro]

In my recent reading of an article on airbrushing a gritty surface is caused by one or more of 4 possibilities. 1. The paint is not thinned enough 2. The airbrush is being held too far away causing the paint to dry before it gets to the surface 3. The pigment isn't dissolving in the thinner 4. There is too much air pressure.

So, everyone has been on track and mentioned all the possible issues. A little testing and you should have it all sorted out.