RE: Ammonium Dichromate

From: Loris Medici ^lt;[email protected]>
Date: 12/29/04-06:17:23 AM Z
Message-id: <002901c4eda0$5b2ccef0$ce02500a@altinyildiz.boyner>

Trevor, it seems pretty normal that you have undissolved AD in your
bottle. Actually, you "should" have some undissolved solid in order to
guarantee a saturated solution. If I'm right, 60gr AD in 150ml water
should make a 28.5% solution. As water solubility of AD is around 25%
(IIRC, @ room temperature), your solution is a saturated one - you can
use it comfortably, just make sure that you don't have solid in your
coating mixture. IMO, your gum is weak; I've used ratios such as 1:1 or
1:2 (gum clumps/tears:water) but I never used low concentrations such as
14.2% (which is the exact concentration of your gum)...


> -----Original Message-----
> From: trevor cunningham []
> Sent: Wednesday, December 29, 2004 11:55 AM
> To:
> Subject: Ammonium Dichromate
> Just finished my first gum! An infrared print of my
> bedroom window (original at:
> Not a lot of contrast, but then I used "burnt sienna"
> with a touch of black (sort of a curry brown)...then
> again, our sunlight is a little hazed out today here
> in Cairo, the local rice farms are burning their waste
> can smell it in the air... another
> question: Why might my ammonium dichromate/distilled
> water solution be forming crystal lumps in the bottom
> of the bottle (glass, dark brown)? IS this normal?
> Or should I dump and begin anew? My solution is 60g
> dichromate to 150mL of distilled water. Should it be
> stronger? Weaker? Gum is 30g to 180mL.
> =====
> "The optimist believes this is the best of all possible
> worlds. The pessimist fears it's true" - J Robert Oppenheimer

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Received on Wed Dec 29 06:17:18 2004

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