Re: Gum and Solutions

>
>Sandy,
> You're right in that the amount of dichromate per 10cc of
>gum/pigment/water (10cc) is .3 grams or 3% technically in Sam's formula, but
>since gum printers use a premixed dichromated water solution (not dry),
>usually let's say 1:1 with the gum/pigment, Sam's .3 grams would actually be
>similar to using a 6% premixed ammonium dichromate solution mixed 1:1 with
>the gum/pigment. When I use my "30% " saturated am di solution mixed 1:1
>with gum/pigment, I end up with 1.5 grams of am di per 10cc of
gum/pigment/dichromate mixture, 5x as much as Sam's.

I actually think that Sam's pre-measured amount might be a little
less than 0.3g and have offered to weigh it with an electronic scale
that is accurate to 0.001g. I don't know how Sam made the
determination that it weighs 0.3g but if you made the measurement
with an instrument with accuracy to only 0.1g the actual weight could
vary from as much as 2.5g to as high as 3.5g.

Sandy
Received on Sun Nov 23 18:03:27 2003