If you place the epoxy in direct sunlight, it will yellow over time. We add UV additive to our epoxy, so this effect does not happen as fast as other epoxies. However, this UV additive effects the color of the epoxy so if we add too much then the epoxy is no longer, "crystal clear".
This is the reason why we call it UV Resistant and not UV Proof.
The UV resistance of this epoxy is what makes it ideal for indoor tables and bars especially tables that are near windows. This product is intended for indoor application only. Although you can use this product for outdoor application, additional steps are required.
After the epoxy is fully cured, you can apply 2 part polyurethane on top of the epoxy. We can't recommend or instruct specific directions on this as 2 part polyurethane is different from brand to brand. But, by adding 2 part polyurethane onto of the epoxy, you will make the epoxy last for many years in direct sunlight.
You have probably seen 2 part polyurethane before and how good it works. It is basically the same product as the clear coat that most cars are covered with. We do not recommend one specific product over another as our epoxy is meant to be a standalone product. This clear coat keeps the paint underneath looking great for years.