I started fooling around with watercolors recently and read about the waterbrush, which you use with your standard dry paint-cake-in-a-box. Instead of dipping your brush in your clean water jar to wet it to get paint from the paint cake, you squeeze the barrel of the brush. Instead of cleaning your now-dirty brush in your dirty water jar, you squeeze the barrel to get more water to flow out of the brush and scribble on scrap paper until it runs clear. GENIUS!

This is most useful for people who do watercolor painting outside, as you don't have to bring a your jars of water with you. I just like the idea of the waterbrush because I'm lazy.

I was at the art store today and looked for a waterbrush, but they were out. Later I happened to be in Target with my sister and they had some in the kids' art section, 5 for $4. (This is cheaper than the $6ish + shipping I'd have to spend to get one online. I'm also cheap.)

The problem: they were already filled with color!

SPECIAL NOTE: This Instructable is mostly to say "hey, look, cheap alternative" and show pictures of the internal doohickeys of this kind of waterbrush. Here are the steps: 1) take apart; 2) dump out the color and rinse; 3) fill with water. Not intensely challenging.

Step 1: Buy, Take Home

The brand was Elmer's Paintastics. What a horrible name for a kid item.

Luckily, I noted that there was some kind of spacer in place between the color (which looked like food coloring) and the brush tip. Which meant that the tips were still untouched by the color. A sinister plot was hatched.

(There were also other brands, but these were the cheapest and I didn't know at the time if what I planned was possible.)

These are pretty decent, actually. The waterbrushes are a good size, and you don't have to squeeze superhard to get water flowing. They also don't constantly drool water.

I got 'em home and took 'em apart over the sink.

Step 2: Take Apart Over the Sink

The brush tip unscrews and the color-reservoir half of the pen has a blue stopper doohickey attached to a tube, which has a white stopper at the other end. I have no idea how it works.

You can get your fingernails under the edges of the blue stopper and pull out the tube assembly. At the other end of the tube from the blue stopper is a white stopper. Pull that out and rinse everything well.

The reservoir half is actually colored plastic, which I didn't know for the first pen I "converted." I kept rinsing and wondered why the color-water wasn't coming out. I felt really smart when I realized the reservoir half was colored plastic.

Just rinse until the water runs clear (a white sink helps here). It's OK if there're still a few drops left; you're gonna squeeze the pen and flow water through everything anyway.

Step 3: Fill With Water and Put Back Together

I'll skip the pictures for the reversal of the steps. Put the white cap back on the blue-capped tube, fill up the reservoir, put the blue-capped tube back in place. Screw the brush tip back on.

Squeeze the barrel a little and squiggle to get any remnants of color out of the works (you can see just a hint of the original yellow in the photo). Voila! $1 waterbrush.

The point is surprisingly good for a super-cheap brush, and the squeezy part is back behind where you grip it. True watercolorists may feel differently, I suppose, but for just fooling around, I think this is a surprisingly good waterbrush, especially to start with.

I deem this experiment: a SUCCESS!

Thanks for reading and enjoy your painting!
Your pal, El Rey

Step 4: Optional: Use Ink Instead of Water!

Thanks to SeamusDubh for the reminder/idea: you can use ink instead of water when you fill it back up! I used Higgins Black Magic ink, which comes with an eyedropper cap. The flow is a little dry, but a gentle squeeze wettens the line right up.