Originally Posted by Baxter Bradford
From the above dilutions it looks like 30 ml of Hypam concentrate plus water to make 270 ml (the lower Jobe min vol) or 60 ml Hypam to make 600 ml which is very convenient. Did you have to worry about the number of films in the drums? i.e. with a large tank, you can load up to 12 sheets 4x5 or 6 rolls 120.
Did you do a residual fixer test or just the standard visual clearing time?
I think I will give this a shot as it is very convenient. Just wondering how much film will stay below the exhaustion rate given the extra dilution. I'll probably try a residual test once I try 6 rolls of 120 at a time just to satisfy my curiosity. It should be OK because 600 ml at your dilution is equivalent to 300 ml at the usual 1+4 dilution - 300 ml in the Hypam fact sheet should be good for approx 7 films. (24 per litre)
I still would like to work out a diverter so I could take the old fixer to a lab that has a silver recovery unit to keep it out of the waste stream. If no one else has tried it, I may see if I can figure out a way with a PIC. Perhaps I can use the air hoses for the diverter as a trigger signal.
Those figures look about right. I mix up 1 litre to make 2 litres at a time. Then use this having kept it in the dark. Lasts me ages as I don't process masses for B+W amd no problem with it going off.
I use 300 ml for 6 sheets of 5x4 since it is so cheap and would rather have a bit extra. For colour I use only 250 ml of E6 chemistry for 6 sheets, don't have a problem. I know that manual says 270 or more, but think that they are being overcautious - I think the early versions of manuals said 250 ml. On rare occasions, I double this for the big drum and 12 sheets - safety is in small batches! It is so easy to use the machine, that 6 sheets is usually ample for my needs.
I did visual clearing (2 mins) and trebled it to give the 6 mins. This x3 factor was a figure I think I got from Barry Thornton when using his Archivix in a Combiplan tank.
Definitely over to you with the fancy plumbing and recovery units!
The dilution of the concentrate is dependent upon
two variables; the amount of chemistry needed to
thoroughly fix the film or paper AND the solution
volume needed to process.
The amount of concentrate can be a fixed amount;
ie, much or little exposed, some specific film or paper
will need some minimum amount. Fix times will increase
with increased dilution. Dan