How I cut, sand, and paint your Acrylic (Plexiglas) project.
Unlike most guides you’ll find on the internet, I used a Dremal rotary tool to cut and sand my acrylic. Many say that using a rotary tool will melt the sheet and to use a razor or specialty razor blade for acrylic but this not the case for my project.
I needed to make a smooth uniquely designed letter “P” for a costume I am working on. I found that my only options were wood or plastic. The plastic I used is a .080”, 2mm acrylic sheet.
To cut the sheet use a fine grit cutting disc similar to one pictured. Take your time, move slowly at a low to mid RPM speed setting on your rotary tool. You are melting plastic and leaving a rough, dirty edge that can easily be cleaned later. It is important to keep the disc as vertical as possible, twisting could easily break the disc and a non vertical cut look unprofessional.
After cutting, you’ll have an edge that is covered in a slag (byproduct of welding) like build up. This can be taken off by rubbing you hand across each side of the sheet.
To clean up the edges and round the cuts (the top part of the “P”) use a finer grit rotary sanding attachment at a lower RPM. Again, move slowly and keep the edge and tool parallel to each other for a clean cut. Also, keep the tool moving so as not to melt the section you are working on.
To make a hole in the acrylic use a very sharper drill bit. Set the acrylic on a suitable surface and drill downward vertically at a high RPM. Again, take your time. Acrylic, like glass and unlike Polycarbonate (Lexan), cracks easily. This only works for small holes (about 1/4”) however the holes made can be widened with the same drill bit! After making the hole you can use the sides of the drill bit (still at a high RPM and moving slowly) to grind away at the edges of the hole to create any rounded shape needed. This process takes patients and time, don’t rush this step or you’ll burn/crack the acrylic.
To paint the newly formed piece, you’ll need enamel paint and (optional) lacquer gloss cote (clear coat). I have not tried other types of paint but enamel sticks very well to the acrylic I work with.
First, degrease and clean the acrylic. Since the majority of the oils on my piece are human oils, I used dish soap then dried with a chamois and then wiped down with a microfiber cloth to remove any lent / small debris.
Apply the first coat in a light mist, an airbrush would be best for this but aerosol cans would work just fine. Keep the distance from the object to the spray can that is specified by the can itself (usually 11” inches). Apply additional coats with in at least a 5 minutes or what’s specified. Allow 48 hours to dry. Enable stays ‘soft’ longer than other paints and thus requires longer to ‘fully’ dry although handling is ok after a few hours.
After the paint has dried for handling, apply the clear in two (more or less coats depending on project) medium, sometimes heavy coats. Wait 3-24 hours before use although handling is typically ok after an hour as lacquer clear coat dries very quickly.
And the finished result, front then back. You may notice some wrinkles around the edges of the black, that is due to poor masking paper which absorbed some of the paint. I had to take off some white (black was the base coat) then touch up the black by hand with a blush and spray again. Gloss black and flat white.
Click here for very basic information on acrylic (and polycarbonate).
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