Recently, as I was concluding a massive project, I learned that if you spray paint on aluminum and then engrave off portions of the paint, you leave a beautiful residual shadow of the paint's color. Because the shadow is so thin, the tinted aluminum reflects light, creating a shimmery effect. (Which you can see here!)
I wanted to combine my newfound effect with what I already knew about making multilayered spray paint stencils, so I created this art piece. Peacocks are beautiful, vibrant creatures, and I knew that I could use the paint etching method to create the iridescent effect that their feathers have.
This project is designed to fit on an 8.5"x11" piece of aluminum, because that's the paper size I had to make stencils. Since I'm including the stencils and the engrave files in this Instructable, you can scale it to whatever size you want.
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Step 1: Gather Tools and Supplies.
Buckle up, cause this is a loooong list, with looooong explanations.
- Because spray paint is both a particulate and an organic vapor hazard, I would highly recommend that you invest in a really high quality half mask that is rated to handle both. In my opinion, it is worth the extra money up front, especially if you plan on doing a lot of spray painting, like me.
- If you can't afford an expensive respirator, you can get cheap disposable respirators that are rated for R95. You can pick those up at Home Depot. The downside is that they don't filter out organic vapors.
Tools & Resources:
- Laser cutter
- Spray booth, or other designated painting area - Always paint in a well ventilated area, where you don't care if overspray permanently colors the surface of whatever you are painting on.
- Fan or drying area - This design uses a lot of stencils. You shouldn't ever put stencils down on wet paint, so you'll need to dry the project between layers.
- Wooden dowel - This holds parts of the stencil down as you move along the stencil.
- Little weights - Also to hold down parts of the stencil. I use nuts, washers, and assorted fasteners.
- Spray paint - Choose your own colors! Or don't! I've tested a wide variety of spray paints, and all of them seem to create that shimmery effect when engraved off of aluminum. I've also included the brands and colors of paints that I've used for my example pieces, if you want to copy mine.
Step 2: Prep the Aluminum Surface.
Whatever texture you create now will show through later when the paint is etched off. I used Scotch-brite to create a brushed aluminum finish, buy sanding in a single direction all across the piece of aluminum.
After you create the finish that you want, take a damp paper towel or shop cloth and wipe the dust off of the surface. Any dust you leave means that the paint won't adhere well in that spot.
Step 3: Cut Your Stencils.
You'll need one of each of the attached files: Stencil1.svg, Stencil2.svg, Stencil3.svg. Because these are so intricate, each one will take some time to cut - even with a laser cutter.
Step 4: Test Your Paints for Compatibility! Test Your Settings!
On a scrap piece of aluminum, test the compatibility of your paints by layering your base, then your colors over the top. Finish your test with a clear coat. Some clear coats do NOT play well with certain paints. While I've tested the combinations that I listed at the beginning of this Instructable, I cannot vouch for any paints that you try on your own.
Using your test piece, figure out your settings for the engraving later. I got the best results from using a lens with a long focal length. The burning of the paint on the gold one is from using a lens with a shorter focal length.
[If you happen to be a user of the Invention Studio at Georgia Tech, my usual makerspace, here are the settings that I used:
- Cutting construction paper stencils: Fig, black lens - Power: 50, Speed: 30, Pass: 1, Air Assist: On.
- Engraving paint: Cantaloupe, blue lens - Power: 80, Speed: 60, Pass: 1, Air Assist: On.]
Step 5: Spray the Base Coat.
Don your respirator and lay down a smooth layer of paint on the prepped aluminum surface. Let the paint dry to the touch. I let mine set for 10 minutes, although I think it was dry enough after 2 minutes. The last thing you need is paint sticking to your stencils.
Note: Spray painting good thin layers takes a lot of practice. Hold the can 8-10" from the surface you are painting, and then make quick, light strokes across the surface. If you do it right, your layers should dry within a minute.
Step 6: Paint Color 1.
Lay the stencil over the top of your aluminum, lining the edges of the stencil up with the edges of your workpiece. Carefully place your chosen weights all over the stencil. Spraying over the stencil can cause it to lift off the surface in the really fragile places. (Lifting off the surface will cause cloudy edges and blurry features.) This is true even for low pressure spray paints, like Montana, so you need to be especially careful with high pressure spray paints.
Gently spray over the stencil with the appropriate color. You may find that the stencil is too fragile to put weights on it at key parts. You can use a wooden dowel to push the stencil down to the surface temporarily.
As soon as possible, peel off the stencil. Ideally, you would do this before the paint dries. If you do it after the paint dries, there is a chance that your paint will lift off with the stencil.
Note: Reusing my construction paper stencils also prevented me from getting good, crisp lines on the gold background one. I would highly HIGHLY recommend using another material besides construction paper, which warps when wet.
Step 7: Repeat for Colors 2 and 3.
Step 8: Engrave the Paint From the Aluminum.
I've attached another .svg file for you! Please engrave the blue filled parts - ignore the red cut lines. That's for another layer that didn't quite pan out.
Step 9: Finish With a Clear Coat.
Brush off any residue or soot left on top of the paint.
Take the piece back down to your paint booth, and spray a layer of clear coat over the top. Because I chose to do a glossy coat, it made the colors pop more in the final design. Make sure that you don't spray the clear coat too close to the surface of the painting. If you do, you run the risk of disturbing and deforming the paint layers.
After the clear coat dries, you are finished!