Video
sign-in for video linkSummary
There two techniques shown in this video.
Color casting
In the first segment, the creator fills one mold with an epoxy that has a red colorant as well as a mold that is dusted with a pink mica prior to filling it with an epoxy that turns white.
These pieces are demolded at about 20:17. They do not zoom in on the parts and its hard to see the finished surfaces.
Flow coating
In the second segment (starting around 6 minutes), the creator uses a clear epoxy. After mixing, he divides it into 4 smaller volumes, adds some colors to each.
With the four colors, he combines them back into a single container, and then without stiring the 4 colors together, the creator pours this on a surfac. The colors come out as a rainbow of the 4 colors. This is referred to as a dirty pour.
Once all the epoxy is on the surface, the creator uses a stick to swipe through the epoxy on the surface, this gives a more complex pattern to the colors.
The creator notes that when pouring colors like this, its important to level the surface. A sloped surface will cause a slight thinning on the high side. This wil be visible in the darkness of the colors.
The creator also notes that spraying the surface with 99% rubbing alcohol, will cause the colors to together were the alcohol drops are yielding a speckled pattern.
Another note the creator makes is that all epoxies will yellow. Some more than others, but if the epoxy is colored, its much harder to see the color shift. UV stabliers will reduce the amount of yellowing or slow the transition, but do not always remain clear. Outdoor surfaces are going to yellow the quickest. Epoxy surfaces exposed to sunlight through a window are going to yellow faster than other interior surfaces.