Re: Carmen's carbon
Albert Strauss (a.strauss@worldnet.att.net)
Wed, 30 Oct 1996 01:21:01 +0000
At 01:53 AM 10/29/96 +0000, you wrote:
>
>Hello carbon persons,
>
>Going over the last batch of information from the list (for which again
>many thanks) with Carmen today, we stumbled over what may be answer (or
>an answer) to the problem. Al says
>
>> dichromate should be around 3%. yours is way too high.
>>
>> recommended:
>>
>> 70 ml water
>> 7 g gelatin (1 knox package)
>> 3 g sugar (one of those individual packages)
>> 8 g Rowney jet black guoache
>> 6 g ammonium Dichromate.
>> photoflow a few drops.
>
>
>Both Carmen and I took that to mean 6 *grams* of *dry* ammonium
>dichromate, which in 70 ml water etc. would be more than 6%, not the 3%
>advised above. Is it possible this means 6 cc of a dichromate solution?
>(The formula she used, BTW, came from Klaus's printout, which could have
>been subject to similar misinterpretation.)
>
>Hopefully,
>
>Judy
>
>
Sorry, slip of the hand, or brain. Yes 6 gms is too high. Cut in half.
However, I believe that you are much better off leaving the dichromate
out and sentitizing it with a 3% solution (half water, half alcohol) after
it is dry, using sponge brush or roller. I have spoiled much tissue because
even a low light level over the many hours it takes to dry will render it
at least partially insoluble.
Al