After seeing a video on powder-coat-filled laser engraves, I decided to try to adapt the technique for use with the studio Glowforge.
I temporarily blocked the air assist to keep it from blowing the fine powder around, which you can read more about by following the link.
The studio laser has a pretty potent external exhaust fan, which kept smoke from being an issue with the air assist restricted.
I wore a dust mask and gloves while working with the powder. I don’t think it is particularly toxic but, I’m sure I don’t need it in my lungs.
I did quite a few experiments on pre-finished 3mm maple plywood and clear acrylic. Initial results with normal initial engrave depth and, settings optimized to melt the powder coat were kind of a bubbly, uneven mess.
A pretty low power level will fuse the powder coat. A little more than that completely vaporizes it.
Increasing the resolution of the fusing pass helps a little, up to a point. Higher resolution delivers more energy to the fill and, also requires adjusting the power to compensate.
Giving the material a shallower channel improved things some. I switched to using half the standard power for the initial engrave, resulting in engraves about .4mm deep. The final result still had a lot of texture.
I finally hit on defocusing the laser for the fusing pass. While there is still some texture in the completed fill, it is a lot smoother.
The general technique is:
- Pin the material down so it won’t move
- Do the initial engrave (at half-power for the normal material engrave)
- Dump some powder coat over the engrave
- Tap the powder into the engrave with a square-end paint brush
- Scrape the excess powder level with the surface of the material using something like an aluminum business card
- Run the engrave again with the poweder coat settings
Using masked material simplified clean up on the test pieces. The un-fused powder wipes off fairly easily or, comes off of the ply with a light sanding, though.
This produces a nice opaque saturated fill and, is available in a rainbow of colors and metallics. It also works great on acrylic.
Settings for Glowforge
Half-depth initial engrave (~.4mm)
1000 / 15 / 340 LPI
Focus for 1/8” stock: .2”
One-minute demo video: