Eye Candy pigment discoloration in a casting:( is it normal or bad batch?

[yaroslaw]

I've bought some Eye Candy pigments recently (never used them before), test cast in one-blank molds with a good result.

Decided to cast 5x5" mold with my standard 400g pour of 1hr working time high quality epoxy (Entropy resins with CCF hardener) and got this result.
Color on the inside disappeared almost completely. The epoxy itself casted without problems - no cracks or bubbles or other signs of extreme overheating.

The pigment in question is Blue Orchid.

It happened to me only once with noname Chinese red pigment. I figured during experiments it was because of resin temperatures during curing and never used that pigment again.

Now, I thought that may be my error that this pigment is not for resin castings or have some incompatibility with epoxies, but all the marketing material clearly states it can be used in epoxy and specifically pen blanks castings.

Pen blank castings almost always deal with higher polymerization temperatures. Never had any problems with Caster's Choice pigments casting same quantity batches.

So my question is - is it a fluke, do all Eye Candy pigments behave the same or just some colors (which?) and what other pigments I have to avoid?

 

[JohnU]

Im sorry to see you had this problem because that's a beautiful blue. I use Eye Candy all the time and I've never had that happen…. but I use it in Urethane resin - not epoxy. I know epoxy takes much longer to cure and wonder if that might contribute to the issue. Also, just thinking…. it might be a different sized crushed powder than the other stuff you've used and may need more in the mix especially if you used it in smaller pours with no problems.

 

[yaroslaw]

Im sorry to see you had this problem. I use Eye Candy all the time and I've never had that happen…. but I use it in Urethane resin - not epoxy. I know epoxy takes much longer to cure and wonder if that might contribute to the issue.

I'm honestly devastated as they have such a great color range, unique colors and availability (as I order almost exclusively from Exotics and they don't have Caster's Choice now).

 

[MRDucks2]

Beautiful cell structure. Is the lack of pigment throughout the pour or just at the edges? I haven't used eye candy pigment in epoxy resin but my wife has.

She said she does not care for it because she has had what seems to be separation of the pearlescence from the color and that she has to mix it a whole lot longer than other mica pigments to get it to evenly disperse in her resin to begin with. She only uses it when she really wants a particular color they have.

Good news is she gives it to me for use in my urethanes!

 

[Bayouusaf]

As JohnU said it may be a result of the epoxy taking so long to cure, that the mica itself settled unevenly in the mixture between when you poured it and when you demolded. I've seen it happen with other mica powder on polyester resin that wasn't catalyzed at recommended mixing levels.