From: Larry Roohr (larry.roohr@comcast.net)
Date: 08/03/03-11:16:06 PM Z
An FYI for anyone interested. As a result of Chris'es note with Kosar info,
I just checked to see how much ammonium dichromate I could get into solution
when heated up, and got up to 13gr in 20ml of Walmart distilled water before
there were a few grains visible in the bottom of the bottle. I added another
gram for 14 grams total and most of it is sitting on the bottom of the
bottle. This is with the brown dropper bottle at about 130degF, sitting in a
coffee cup partially filled with hot water sitting on an electric cup
warmer.
This helps get gum mixes with less water and more dichromate if desired,
without having to resort to mixing dry dichromate.
To use Stuarts first coat mix as an example, 10ml gum, 2 gr amm dichromate,
and 2.5ml water, you could get as close as 10ml gum, the same 2.5ml water,
and with this 65% saturated solution get 1.625 grams of dichromate in there.
Not quite a match up with 2gr but certainly more options without going the
dry route. With 2.5ml room temp 26% solution you'd end up with .65gr
dichromate in the mix.
One thing I did not check but should have, and will, is how much the total
volume of liquid changed as a result of adding the dichromate. If it did
you'd need to add more to get the 2.5ml of water and calculated dichromate
in there.
Larry
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