WEST (the brothers) sells a kit to do just that... with the scale and a bunch of mixing cups and sticks. Your local marine place should have it, under $40. My local "West Marine" has it.

: I just stumbled upon a method of getting the right proportion of Resin to
: Hardener that is unbeleivably simple. (Forgive me if this is redundant). I
: was stumbling around tryng to find all my grauated scales, and information
: sheets when I thought of this: West 105 Resin and 205 Fast Hardener. Ratio
: 5:1 weight and volume
: (207 hardener which more of us use is 3:1 volume 3.5:1 weight)
: I have a small digital postal scale, 1/10ths of an ounce.
: I first place an empty plastic cup on a paper plate on the scale then turn it
: on. It resets itself to Zero (ignoring the weight of the cup and the
: plate)
: Next I fill a pour a little resin into the cup. 2.5 ounces (weight)
: Then all I have to do is pour in .5 ounces of 205 Fast Hardener bringing the
: scale up to 3.0 ounces.
: Done!
: I haven't wasted any hardener that won't pour out of the hardner cup, I don't
: need to worry about the menicus and I haven't gummed up three-four plastic
: cups.
: for 3.5 to 1 ratio, just hit a multiple of 7. 7 ounces resin, 2 ounces
: hardener (look for 9 ounces ont he scale)
: 2.8 ounces .8 ounces of hardener. look for 3.6 etc....

: Will