I need more information. Generally speaking, with Alumilite being a notable exception, many epoxy resins suffer from direct exposure to UV. Another "problem" with some epoxy resins is that they do not dry clear and have a tendency to "yellow" with age. Another disadvantage of the epoxy resins is that in almost every case, epoxy resins are more expensive to use simply because of their two "equal thick" parts make manufacturing more expensive that poly resins that use "fractional, thin" catalization.
Again, Alumilite Water Clear and Crystal Clear are epoxy resins that are exceptions to virtually all of the disadvantages I listed above, and, in fact when structural integrity is required or less brittle "threadable " resin is needed, Alumilite is usually a better choice for resin casting.
Without knowing the manufacture and brand name of the epoxy, it is difficult to give you solid and accurate information. While the "basics" of epoxy is the same from one to the other, each manufacturer and each epoxy brand may have VERY dissimilar "specific" properties.
Respectfully submitted.