Sludge in Print Fix.

[pentaxpete]

I make up my own B/W print fixer as I have been given a sack of Sodium Thiosulphate crystals,1Kg dissolved in 5 litres warm water, then I add some Potassium Metabisulphite tablets from a wine-making shop to acidify it, but as I don't do so much B/W processing now, when I came to use the fixer the other day ( and I use 2 fixer baths, both 5 litres ) there was this horrible brown SLUDGE in it which took ages to filter out.
Do you have the same problems- is it not Acid enough perhaps ? I use a kodak indicator Stop Bath.
I have also found a YELLOW sludge in Hypam concentrate I was given from a local newspaper, which is Sulphur no doubt, but I filter it off and the Hypam still seems to work for my B/W film fixing.

[Les McLean]

I make up my own B/W print fixer as I have been given a sack of Sodium Thiosulphate crystals,1Kg dissolved in 5 litres warm water, then I add some Potassium Metabisulphite tablets from a wine-making shop to acidify it, but as I don't do so much B/W processing now, when I came to use the fixer the other day ( and I use 2 fixer baths, both 5 litres ) there was this horrible brown SLUDGE in it which took ages to filter out.
Do you have the same problems- is it not Acid enough perhaps ? I use a kodak indicator Stop Bath.
I have also found a YELLOW sludge in Hypam concentrate I was given from a local newspaper, which is Sulphur no doubt, but I filter it off and the Hypam still seems to work for my B/W film fixing.

It could be the Metabisulphite tablets as there may be other chemicals in them or, it may be that you have added the Metabisulphite when the Thiosulphate solution was too warm and caused some sort of precipitation.
When I mix my own fix I mix both chemicals sperately and leave the solutions overnight to cool and mix them together the following morning.