Ri:bleach/etch or mordancage

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alnovo@inwind.it
Date: 03/22/01-01:06:05 AM Z


> The formula in the Ilford manual is 30g copper chloride, 100 ml of
> acetic acid 80%, and water to make 1000ml, with an added hydrogen peroxide
> 20vol just prior to use. The Shutterbug article calls Hydrogen Peroxide
> 20vol equivalent to 6%. Is this correct? The Shutterbug formula only has
> 80ml of the glacial acetic acid, but otherwise is the same (oh--is 100ml 80%
> acetic acid equiv to 80ml glacial acetic? If so, the two formulae are
> identical)(can you tell I didn't take chemistry?) These two formulae differ
> quite a bit in measure from Jonathan's, but not in content.
> Chris
>
>

20 vol is equivalento to 5.83%; 6% might be simply an approximation. Hovever, as the concentration of H2O2 decreases increasing the storage time, such quantities can be deemed the same.
80 ml of 100% glacial acetic acid is almost perfectively equivalent to 100 ml of 80% acetic acid
(the equivalence would be be perfect if all quantities were expressed in grams, and concentration were in grams/grams)

Ciao
Alberto


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