Epoxy Resin and coloring

[mjmeldrum]

Hello everyone. I think l'm in the right subject area for this post. Here's the back story. I got some epoxy resin for casting my own blanks for Christmas. I've now done two castings with similar results. I wanted to use two colors both times. I mixed them up and poured them into my molds. When I demoled them the colors had separated. By that I mean one color was on the top the other on the bottom. It almost looks like I made these blanks in two distinct pours. I used my stir stick to attempt swirling the colors after the pour but no luck. I'm wondering if I maybe should have let the epoxy sit for a few minutes before pouring into the molds. The epoxy says it has a 40 minute working time and I didn't come anywhere near that open time before I poured. I could use a voice of experience to help me identify what went wrong and why. Thanks in advance for your assistance.

 

[hokie]

With any resin, but especially epoxy resin, you'll want to wait until the colors have thickened a bit and nearer the end of their pot life before combining in a mold. Many of the newer epoxy resins are really thin in order to allow bubbles to release from the liquid before curing and so you'll need to wait longer than if you were doing a single color pour.
As far as why your colors separated, I am not sure what you used to color your resin, but my guess is one of the colorants is much heavier/denser than the other. I've rarely heard of such an issue, to be honest. Usually the complaints are about a lack of contrast between the colors and that everything looks a little too well mixed as a result of not waiting for the individual colors to thicken.
Good luck!