Etching away paint on acrylic

projectinspo

#1

I’ve been experimenting with ething away paint on acrylic materials. I like the idea of creating two-tone designs by painting onto acrylic and then etching it away. I’ve been happy with some of the results, and I’m continuing to experiment – but I’d like to improve the cleanliness of the etched away areas. On clear acrylic, I’m generally happy with the frosted look. But on colored acryilc, I don’t get the finish back that was on the surface. I understand it won’t be smooth again, but if I could restore the color of the original surface I’d be happy.
I’ve experimented with depth of etching, which helped (see the giant fist on the left) but I’d love to know if other people have had success with this, or with other techniques in two-tone design.

I tend to have designs that are too complicated to go back in and manually paint after the fact.


#2

I have no idea if it will work in acrylics, but when we sand away support on other plastics like PLA and PETG, afterwards they are frequently white from the sanding.

We get rid of the white marks by slight application of heat with a heat gun. Just a quick blast - if you leave it on too long, it will soften the material and start to lose shape.

But it might be worth a small experiment on an extra piece to see if it works to smooth out the dust. :slight_smile:


#3

It’s definitely worth a try – thanks for the suggestion!


#4

Defocus the laser (above the work) instead of focusing on the surface or middle of the piece. You’ll get a wider beam that tends to melt slower vs the faster melt/burn of a focused beam.


#5

Thank you for the suggestion – does that rough up the edges of the etched areas? An unfocused beam seems like it wouldn’t give as sharp an edge.


#6

Correct - you get a softer etch. But, you can do it in 2 passes first with the unfocused and then focus it and do an edge cut along the contour of the etch design. I do that a lot regardless because it makes for nice clean edges to engraves where minute fractions of start/stop movements can affect the overall “cleanness” of the look of the engrave.


#7

When using clear acrylic, if you hit a sanded or etched surface with either clearcoat paint or clear resin, it actually restores the clarity of the material. The effect gets better the more clear you add and the closer it gets to having a flat surface again. The clearcoating also helps protect the other color of paint you added as well.

I have not tried this with colored substrates, but you can actually simulate the effect by running water over the surface and observing. Water will turn etched clear material, completely clear again while it is submerged and the water is filling the etched surface. Once it dries, the etching appears as normal.


#8

Adding some acrylic solvent (or maybe some other solvent like paint thinner or acetone) might bring the color back. Flame polishing might do it too.

I haven’t engraved or even cut any extruded acrylic, but I guess one of the “problems” with it is that it doesn’t get the same frosted look as cast acrylic when engraved, but perhaps that’s the exact look you’re after.

I got some solvent in the “2” here. It was an accident, so not much got on it.



#9

This is really cool art work


#10

Thanks! Definitely going to try that.


#11

Thanks!


#12

If you wanted to paint it. You could mask the piece off, engrave, LEAVE the remaining masking on, then paint it. You can use regular spraypaint and then peel the remaining masking off once its dry. Should keep the paint where its supposed to be.

Good luck with your experimentation!


#13

LOVEEE the fist. So much. Wow. Well done!!


#14

Perfect solution, basically the tried and true practice of color fill. You’d probably get better paint adhesion too.


#15

If you do multiple layers pausing in between and paint while it’s in the laser (brush paint is easier) on reverse engraves you can build up a bunch of different colors and it’s the first one in any engrave layer that shows from the front.


#16

acrylic cement is amazing! I have messed up, fine sanded, then brushed or misted acrylic cement, and you can barely tell it ever changed.
it’s a bit of a challenge, it’s very low viscosity, great for getting into cracks or seams but will run if over applied. I guess it’s all dependent on what kind of paint you’re using and whether it’s will be melted by the solvent.