This sounds bad at first, but since you have a set ratio of the two, this means you can mix up only what you need and have little to no waste. Most good epoxy systems (TotalBoat is what i use) comes with a pump system that you can use that means you take one pump of part A and part B. Although it is a tad more pricey, it can be used inside! though, you will want to get air flow as the epoxy resin smell (though not as dangerous as polyurethane) can case issues in small spaces. However, if you don't have a yard, or don't have good weather, you can swap out from polyurethane resin to a two part epoxy, more commonly used for boat building. It's also cheap, easy to find, and does a good job. For some people, this isn't an issue, as yard space and weather is on their side.
Polyurethane resin (as used in here) is really smelly and can cause issue. Since this was the post that got me into prop building, I figure it's only fair I share something I just found out!
