Re: Reversal Bleach & Contrast Control


Kevin O'Brien (kob@paradise.net.nz)
Thu, 11 Mar 1999 16:35:09 +1300


>Pot. permanganate + sod. chloride + acetic does bleach - very quickly - but
>leaves a fairly strong orange-brown residual image which does not clear
>(clear in 5% sod./pot. metabisulphite, though 5% sod. sulphite also seems
to
>work). This, I believe, is permanganate-stained silver chloride, as it can
>be redeveloped.

Leave out the sod chloride for reversal use.
The acetic acid is only vinegar strength.

It's likely that citric acid may be able to be substituted for acetic which
would give an odourless soln using a harmless food product.

Kevin



This archive was generated by hypermail 2.0b3 on Sat Nov 06 1999 - 10:09:02