# How to use finger nail paints (polish) to paint a Rubik's cube



## CarlBrannen (Dec 16, 2012)

I got a PM asking about how to paint a Rubik's cube. You can do this sloppily quite quickly. To get a nice result takes some time and since it might be of general interest, I'm giving instructions here. Some painted cubes. My color scheme replaces yellow with black, and I use gold instead of orange, and my blue is metallic. This makes red and "orange" easier to distinguish:







I use fingernail paints. If there's a "Dollar Tree" store near you, you can buy these for $1 each. Otherwise consider waiting for sales. Generally speaking, more expensive paints go on easier and sometimes require fewer coats. You should be aware that each company sells huge numbers of paints with only slightly different colors.

Make sure you either buy enough, or know where you can buy more and know what to buy. Avoid driving to the store with the intention of buying more of, for example, "white" fingernail paint. You will discover that the same company sells three different white colors. For example, OPI sells three white colors: "alpine snow", "funny bunny" and "my boyfriend scales walls". All the other colors are similarly duplicated.

Since fingernail paints all use the same solvent, you can mix them. I begin with a partly full bottle and simply pour another bottle into it. The paint is very thick, compared to the diameter of the bottles it comes in, so this is easy to do. After pouring in the new paint, you need to mix in thoroughly. I mix them by stirring with a thin rod. Because of the high viscosity, you can also use a thicker rod and turn the rod between your fingers.

Before using a paint you need to stir it as the pigment sinks to the bottom. This is worse with the metallic colors. Don't shake fingernail paints you'll get bubbles in them that will ruin your finish. Instead, they should be swirled between the hands. This works best with the cylindrical bottles. This also warms the paint up to hand temperature which makes them flow easier.

Finger nail paint bottles include brushes but the brushes are somewhat unprofessional. You'll get a better job from real paint brushes. Art stores sell the best but good brushes are expensive. Ask for advice at the store or better, ask a friend who paints. In general, for cubes, you want a brush that is just as wide as the cubies you're painting as this will avoid seams between strokes.

Test your paints to see how well they'll cover.

I like to paint black cubes and these need 3 or even 4 layers to hide the black. Paints which are more translucent should be avoided. Most pinks are translucent. You might have success with these on a white cube, or they might work on a black cube if you lay down two or three coats of white before painting the pink.

You paint one side at a time. You need to mask the edges. I use Scotch Magic Transparent tape. I avoid other types of Scotch tape, it must have "magic" in the name. This peels off better and leaves a sharper edge.

The tape comes in rolls about 3/4 inch wide. I use a contraption made from razor blades to cut the tape into strips of the appropriate width. The bigger the cube (i.e. 7x7x7), the smaller the strip as the cubies are smaller. On cubes with gaps such as the modern speed cubes, I ignore the gaps and paint right over them. The paint is so thick that it doesn't slip down much into the gaps. You end up with square paint patches on cubes that would have used chamfered inside corners on the stickers. (I.e. see http://en.wikipedia.org/wiki/Chamfer#In_printed_circuit_board_.28PCB.29_design ) I think square looks better and it's cool when someone sees a retro square "stickered" cube but then realizes that it's actually a modern speed cube in disguise. Masking chamfers would be difficult. If you want that effect, I'd paint it square and then cut the excess paint off with a razor blade after it's dry.

After giving a coat, let the cube dry perhaps 5 or 10 minutes. This is not long enough for the paint to become brittle. Give recoats waiting 5 or 10 minutes between them. I should probably point out that new lacquer coats dissolve old coats so you shouldn't mess around when you're giving a side it's 2nd, 3rd or 4th coat. Just put the paint on, if you mess around you're going to dissolve the lower layers and it's all going to move around on you.

Now wait about 4 or 5 minutes. The idea is to let the paint dry to the point where it is not soupy, but not so dry as to become brittle. Ideally, you want the paint at the consistency of cheese. At this time you remove the mask.

To make the mask easier to remove, put all the strips down in one direction then put down the perpendicular strips. Remove them in reverse order, one at a time. It's better to pull up fairly quickly so the paint is split (rather than stretched). This will leave you with patches of paint that are thick and look a lot like somewhat thick stickers. If you pull off too slowly and or too soon, you'll get paint spatters. If you pull off too quickly or too late you'll end up with paint tearing, that is, the edge will look like torn paper instead of a clean cut edge.

If the paint tears, it tends to pull up corners. While these are wet, you can push these back down with your finger. It might be useful to keep your paint handy so you can touch up these sorts of tears. You'll probably have to do some touching up after it's dried.

It's useful to paint an extra plastic surface at the same time as you paint your cube. Then you can judge when the correct time to mask is by testing on the test surface. You can also use the test surface to verify that the paint is dry enough to sand, etc.

Let the cube dry for an hour or two before trying to paint another side. Otherwise you're going to leave marks in the still soft paint (especially with the very thick coats which take so long to dry completely). Do three adjacent sides at a time. You can do this without having to touch the already painted sides. Now let it dry for a couple of days before painting the remaining three sides. Be very careful where you put the cube as the fresh paint is very easily marked and will stick to things.

Once you've got the whole cube painted, let it dry for perhaps a week.

Yes, that's right, I said let it dry for a week. And during that week, let it rest on its edges. Don't leave it sitting on a flat surface or the paint may bond to the surface. Make sure it's a relatively warm place so the paint will dry thoroughly.

Fingernail paints on a cube take a lot longer to dry than on a finger nail. This is for the following reasons: (1) Fingers are warmer than cubes. (2) Fingers keep moving around so they get air flow. (3) Cubes end up with thicker paint. (4) Fingernails absorb solvent so fingernail paints "dry" on both sides, that is, they release solvents to the air and to the body of the user. Wearing gloves is a good idea (I never do) and make sure you have good ventilation. The solvent for fingernail paints is usually ethyl acetate which is less toxic than most other solvents but still it has an MSDS: http://www.sciencelab.com/msds.php?msdsId=9927165

Now you can solve with it, but it's not quite done. The different faces will feel different if you used some glitter paint, or certain "gel" fingernail paints that go on especially thick, and some smooth paint and this is illegal for competition due to the different feel. In addition, fingernail paint is somewhat brittle and will chip off. So you need to put a guard coating. I use spray enamel.

Anyway, before giving the top coat, I'd recommend solving the cube a couple hundred times. When you pull off the masking, there will usually be little stringers of paint and solving the cube will knock a lot of these off.

After the cube is very very dry you need to smooth the surfaces with sand paper. The sand paper to use is 1000 grit which you can buy at places that sell supplies for painting cars. Use a flat surface to support the sand paper. This probably works best if you disassemble the cube and sand it a cubie face at a time. The reason for this is that a cube doesn't have equal heights on its cubies. If you sand too much you may have to touch up a face or two. Don't worry so much about these little imperfections, the worst painted cube looks better than the best stickered cube after 1000 solves.

After smoothing the surfaces with sand paper, it's time to clean up the masked edges. Some faces are nearly perfect. For the others, I use a razor blade to scrape unwanted varnish off of the cube. Don't worry about marking up the black plastic, after you give it the top coat the black will look smooth and beautiful.

When painting on top of old paint, it's important to follow the Lacquer Enamel Varnish (LEV) rule. You must always paint lacquers first, then enamels, then varnishes. Otherwise they will not stick. Fingernail paints are "lacquers" so they go on first. I use a clear gloss enamel as the top coat; I like how it looks and how it feels on the hand.

Probably the highest quality top coat would be the clear top coat in making car paint repairs and I will try this soon. I believe that these are enamels nowadays. By the way, modern fingernail paints were invented in the 1920s as a consequence of new developments in automobile lacquers. Women decided that their finger nails should look as nice as the nice cars. If they'd been invented in the 1990s their use would have been banned because they're made out of noxious chemicals. Be sure and use a well ventilated area to mess around with fingernail paints.

Before putting on the top coat it's time to put on your logo. I put information on. By WCA regulations, this goes on a single cubie. I use the white side. I've got my name and cell phone on there, and complete identifying information as to the type of cube it is and the date I labeled it. To write really small it helps to have a 0.1 mm "technical pen". Staedtler is one of the brands. These are not cheap: http://www.staedtler.com/Mars_matic_700_gb I'm sloppy at my logos, I really should put more effort into it...

I reassemble cubes before giving them their top coat. The more modern cubes have gaps between cubies. I fill these with modeling clay so I don't have to remove enamel from the guts of the cube. The enamel I've been using dries in 30 minutes or so. I let it dry about that in between coats. After another 30 minutes of drawing, I disassemble the cube again. I do this early because the top coat will glue the cubies together so this is easier before it dries really hard.

Now it's time to let your cubies dry out again for perhaps another few days. Enamel dries faster than varnishes as it is a chemical reaction.

After it's completely dry, it's time to clean the enamel off of the moving surfaces of the cubies. I also lightly sand all the external faces (so that they're all identical). Again, use the 1000 grit sand paper, and if you want to polish it you can use the usual techniques.


----------



## benskoning (Dec 17, 2012)

Interesting, I will have to try this.


----------



## cubingawsumness (Dec 17, 2012)

Could you post some pictures of cubes you've painted?


----------



## Xenon (Dec 17, 2012)

tl;dr try to make it shorter next time.


----------



## bluecloe45 (Dec 17, 2012)

I did this with some old Diansheng to make it black. Didn't really do it right I guess.


----------



## Isaac Paurus (Dec 18, 2012)

couldn't you just use sharpie paint markers?


----------



## Wassili (Dec 18, 2012)

Isaac Paurus said:


> couldn't you just use sharpie paint markers?



Paint markers tend to scratch off on plastic surfaces.


----------



## CarlBrannen (Dec 19, 2012)

I added a photo of some painted cubes. I thought I'd photographed the process but don't know where I left the pictures. If they turn up I'll add them to the above using the "spoiler" thingy so they don't take up too much time downloading.


----------

