This is a prototype that my wife and I set up this past weekend, using some scrap MDF from building the wasteboard. Total size is about eight inches in height, and the deepest spots of the V-carve are about a quarter inch deep. This was done with a 60-degree bit and fairly aggressive feeds using the stock spindle, then painted with craft-store sourced Ceramacoat acrylics. We painted the lines, sanded the surface to remove slop, then my wife painted the rose detailing. When we applied urethane to finish this (after this photo was taken) we got some odd ‘puffy’ looking gunk in the deepest corners. I think it might be some kind of reaction of the paint or MDF to the urethane, so fair warning! Next time, we will use sanding sealer before the paint, just to be sure. With natural wood, that’s essential to prevent bleeding of paint along the grain, but it hasn’t been in MDF up to this point. Live and learn!
That is really sweet !
Would you be willing to share the g code for it? I make jewelry and keepsake boxes for fun and a little extra $$$ and it would look nice in that setting.
Prior to painting engravings i like to spray blonde shellac as a sealer and let it dry thoroughly then apply my colors. Lacquer thinner takes the excess paint from the surface but does not affect the shellac which I then sand off the main surface, cleaning things up nicely. the I recoat with shellac before the final finish.
I hadn’t considered using shellac as my sealer, I’ll have to give that a shot! I’ve been using either commercial sanding sealer, diluted titebond glue, or minwax spray-on poly as my sealer before paint. I do have a tin of shellac as well for my pen sac work, so I’ll give that a shot. Thanks for the idea! On natural wood, I’ve been sealing, painting, then running it through my planer set to take off the tiniest cut I can manage. I just very slowly lower the planer (say, .010 or so at a time) until I get the paint completely removed. Of course, that’s no good for something like this where part of the surface you want to keep paint on. Shellac seems like just the ticket for cleaning up with some lacquer thinner…
I’d be happy to share the G-Code, this was generated in V-Carve and posted with their standard GRBL post. Works fine on my stock X-Carve without any modification. I haven’t tested the spindle control, though, I normally just flip it on manually before I start the cut. Soon as I get home, I’ll post the code. Or, if you have V-Carve, I’d be happy to just post the project, so you can scale it as needed.
I’ve been getting good results while testing with MDF by using ordinary car spray primer. Seals, gives a good surface for paint and sands off easily. Really important to really let it dry before painting over though.
Sounds like a good choice for MDF! I’m primarily trying to stick with transparent ones, though, since most of my actual (non setup / testing) projects will be in solid wood. I’ll have to give that a shot on the MDF in one of the next rounds!