Re: Elmers Fiberglass Resin
Everyone has their own opinion on waxed vs. unwaxed. I use unwaxed laminating resin, and add surfacing agent as necessary if I know that I want to get right into sanding it. Just out of curiosity, what type of small repair are you using it for? That might make a bit of difference, because as ondarvr mentioned, these resins are sometimes designed to perform in different ways. You can adjust shrink, flex, thixotropy etc.
Here is an article titled, "Elmers fiberglass resin sucks." Could be worth a read, but I don't have any experience with it one way or another.