: Hi Pete;

: Using your numbers (12 & 11 lbs) I come up with a 1.96% error for a 2:1
: mix. I don't think you could sight levels of the 2 different viscosities
: in a mixing cup better than that!

: Best Regards, Spidey

This is not George, and I don't want to start a food fight, but follow me through on this. Let's assume that resin weighs 12 lb/gal and hardener is 11. Sounds harmless enough. Let's further assume that you want to make a 1.5 gal. batch of the stuff, but you do it by weight instead of volume. If you put 12 lb. of resin with 6 lb. of hardener, instead of .5 gal of hardener, you actually use .545455 gal. So you actually have 9.09% more hardener than you should. That is not a trivial error.

Using a scale is fine, and taring it to the container eliminates a variable. I'm just saying that when you compute the weight you want, compensate for the density difference. It matters.