Ive mixed a lot of batches. I like the 3oz batch size best, and will usually make two 3 oz rather than one 6oz, just because I'm afraid it'll go off in the pot. I made a simple mistake the other day; poured the hardner first. Apparently the smaller quantities are not as accurate on the cup, or are harder to judge by eye. Perhaps a scale would have put the margin within tolerance, but perhaps not. My SOP is; develop a system that works for you and use it consistantly. Another point is that the bigger the batch size is, the wider the volume of the margin of error. In other words, one drop may be enough to throw a 6cc batch, but it doesnt matter in a 3oz batch.

: What makes you think that a person who has problems using a pump (you only
: have to keep the epoxy and resin warm for the pumps to work reliably) can
: make a measuring "cup" or a scale work reliably?