Adding a coloring agent to WEST SYSTEM® Epoxy is frequently done to make colored castings, highlight an epoxy-coated surface, act as a colored base coat for paint, etc. Most powdered pigments are satisfactory, as are acrylic paste pigments and universal tinting pigment.
Adding pigment to epoxy should, like everything in life, be done in moderation. Without exception, adding pigment to WEST SYSTEM Epoxy will weaken the cured mixture to some degree. Because of this, WEST SYSTEM suggest you use very small amounts of pigment, about 5% by weight. As a result, thin films of colored epoxy are somewhat transparent. It usually requires several coats to make the film opaque.
WEST SYSTEM pigments are available in three colors, white, black and gray. WEST SYSTEM Pigments are suspended in an epoxy resin base which allows them to blend thoroughly into the epoxy to make very uniform colors. Because the pigment has an epoxy resin base, it is important not to add more than the recommended amount. Adding an excessive amount of pigment to the epoxy could alter the resin/hardener ratio, compromising cured epoxy performance.
If you need to make a tinted epoxy putty for filling defects, mix WEST SYSTEM epoxy with 406 Colloidal Silica Filler to make the putty. The addition of 406 to the epoxy results in an easily colored, smooth, off-white paste that can be tinted with one of the pigments.
Epoxy, tinted or clear, does not have good UV light resistance. An epoxy coating exposed to UV will yellow, become opaque, and eventually flake off. This process takes a while and if the object you are coating has limited exposure to sunlight, a colored epoxy coating will hold up for years