BEWARE of the use of your colorizing pigments. Many of those only take from 1 to 3 drops to get the same blue color I see in your photos. You don’t want to waste pigment by over applying!
Very true. I was not aiming for any specific color for this try but indeed I used different mixes for each side and still they ended up the same greenish blue color. Since then I ordered actual coloring pigments so I’ll try to use a very small amount next time
Can you put the project back on the CNC and do a leveling toolpath to bring down the excess epoxy to the surface of your material?
That would definitely have been the smart thing to do, and I even had the jig to do it as this was a two-sided job. I don’t know why I did not think of that… One more thing to add on my list for the next one !
I’d want to do a test piece, to see what kind of finish you get. You’d have to go with very shallow cuts so you could keep the ipm fairly high. Apparently epoxy gets “gummy” if it heats up, will stick to your endmill. http://www.crosslinktech.com/support/tips-and-tricks/machining-components.html
Yeah I think it probably behaves like acrylic, which I have successfully cut before (low RPM and fast feed), though I have never done a surfacing pass on plastics so I’ll have to experiment a bit
follow-up: I used the machine this time to remove the excess epoxy, and it worked like a charm.
12.000 & 2000mm/min for the surfacing, no glued up endmill, very light fine grain sanding after that, easy enough.
Julien, thanks for the view and what you did with this piece. I’m going to have to try that on my next set of coasters as it should be faster than sanding down to a fine finish. I am going to try and mix a clear batch of epoxy and thin it enough to use a sponge brush to apply it, hopefully without air bubbles.
It’s been a busy week-end, but I’m finally done with this series of coasters. I did three sets of 8 coasters, for friends that happen to be fans of Valentino Rossi. On the plus side, I confirm that bamboo and epoxy love each other. No need for sealer, zero bleeding, it’s almost too easy. Shaved off the excess epoxy with a surfacing operation on the Shapeoko, and now I wonder how I could bear doing it manually before. My only regret/failure is that some of the colors came out very faded, I guess the cheapo coloring thing was not very good quality. But otherwise I’m quite pleased with how they came out.