Hey all, pretty confused here and this is messing up some projects of mine. I often times skin some items in carbon fiber. I use resin research epoxy. I mix by weight on a scale and am positive I have everything correct. I have been working with resin research for a long while. Anyways everytime I skin something it will look great in the shop, but out in sunlight the epoxy turns blue and is all discolored. You can even see brush stroke patterns. Any idea whats going on? 

Sounds like a additive in the resin if it is actually changing colour.  Seeing brush strokes and other marks could be due to the sunlight making the resin soften on its first exposure to heat. The resin tends to settle a little which means brush strokes and any minor blemishes show through more as well as "print through" of the fabric pattern.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant