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This post could fit into several subforums. I'll just post it here.

I've been experimenting with epoxy resin to emulate mother of pearl and abalone for inlay. Shell and ablam are increasing in price. And they're on the lowest level of the CITES list. US Fish and Wildlife are keeping an eye on how much people import. I'm starting to design fretboard inlay and although I'll still use mop and other shell for inlay, I decided to see what I could come up with, using epoxy resin.

I've never used art epoxy resin. I did a practice pour and subsequent cutting, both on the cnc, and by hand with a jeweler coping saw, and it works nicely. So I've been trying to figure out how to make it look like various Linds of mop. I finally had some success.

My first attempts, while pretty, didn't emulate mop. I'm after the iridescent color shift.

That looks, at least in the picture, sort of opal-ish,

MaineGeezer wrote: ↑Mon Dec 06, 2021 10:25 am That looks, at least in the picture, sort of opal-ish,

Yes, it does, so I hope to use it some day...

The colors are nice, but I'm trying to mimic mother of pearl, which has color shift. I found interference powder. In a nutshell, interference powder is mica pigment, which has been coated with titanium dioxide. It's also extremely fine, like flour. Unlike mica, it's not sparkly. It's pearly, which of course, is what I'm after. I bought red, green, blue, and violet. When you look into the jar, it just looks white. Look through the jar and you'll see the color when the light hits it right.

My first try was okay. Not magnificent. I got a little color, but nothing to write home about. I started thinking about it and interference powder basically refracts light. So, if it has a color, or solid background, you can see the colors better. I tried adding just a tiny bit of opaque white. The interferance powder just disappeared in it. My next experiment was with transluscent white (remember, I'm trying to make MOP at this point). I only added 1 drop in 100 ml of epoxy. The colors that the interference powders made, just disappeared again. Then it dawned on me. As a scientist, a biochemist, I know that black is the total absence of color and white is all color combined. The white simply absorbed the color refracted from the interference powder.

Also, I've never worked with art epoxy. This 2 part epoxy has a reaciton which causes an exothermic reaction (it heats up). Winter is here and we keep our house pretty cool. My shop however, hovers at 63-64 degrees. This is too cold for the reaction to really work, so that was another reason I my colors were mixing, rather than staying separated. So, I had 2 things to correct; I had to provive a heated space and if I wanted more color, I had to figure out how.

This is where I'm at now:

The furnace is in a small room about the size of a small walk-in closet. I store my molds and things like that in there. It's warmer than the rest of the basement. Also, I bought 2 100 watt ceramic heat bulbs (used for reptiles), to further heat my work area. Ideally, the temp should be around 75 degrees. Secondly, chemicial reactions occur quicker and more thoroughly when you have more reactants. I've been mixing all 4 colors separately. This time, I mixed all 200mL of epoxy together and waited for the temperature to begin to rise in the silicone beaker. When I felt it warming, I poured 50ml into 4 separate beakers, added the interference powder, and also a very tiny amount of corresponding translucent powder. In the violet, I used violet, red in the red, green in the green, and blue in the blue. It was such a small amount that it didn't color the epoxy, but you could see the interferce powder brighten.

Interference powder never really mixes with epoxy, it swirls. The epoxy started thickening before I poured it.

The results are pretty stunning in person. The color shifts as you turn it. I'll resaw it, much like you would wood, into thinner slices.

I started using a similar process for pickguard

Beautiful!!

Looks like you might be on to something, great persistence. Will the cutting leave saw marks and how will you get rid of them, sanding might fuzz up the effect?

Bruce,

Hey Diane, don't forget the charge extra !!!

Brent