TF-4 and water stop, or lack thereof

bwrules · Apr 28, 2011

Hi. TF-4 instructions say that it should be used with a water stop for 30 seconds. Since both the developer and the fixer are alkaline, wouldn't it make sense to skip the stop all together? Thanks.

Barry S · Apr 28, 2011

Would you rather dilute your working fixer with developer or water?

Dan Dozer · Apr 28, 2011

I may be wrong here, but I assume the intent of the short water wash is to get most of the developer out of the paper before you put the print into the fix. It seems to me that if you went straight from developer to fix, you are introducing chemicals in the developer straight into the fix and possibly compromsing the life and/or chemical make up of the fix.

PVia · Apr 29, 2011

Use a running water stop with TF4, or change the stop water every few prints.

Rick A · Apr 29, 2011

I use regular stop but diluted 1+1 since I dont have running water. You can use a water rinse only as per instructions, but it must be changed frequently(or running) for paper. TF-4 will withstand full strength stop, but wont last as long.

Dan Henderson · Apr 29, 2011

I believe that along with removing most of the developer to avoid contaminating the fixer as Barry said, but also to greatly slow down continued development. Water probably does not completely stop development as an acid stop bath does, but as long as the little bit of continued development in the water is factored into the test strips or other method that you use to determine exposure, it is not an issue. I have used a water stop ever since switching to TF4/5.

john_s · May 1, 2011

I think it's worth rinsing most of the developer out of paper before going into the fix. I used to use water rinse before putting fibre paper into slightly alkaline fixer and I got stains occasionally which were not obvious until later.

Then I began using a long rinse with a change of water (not timed but longer than 30 seconds), which was better but time consuming.

Lately and preferably, I rinse in a quite dilute solution of sodium metabisulphite (slightly acid) which I think is more compatible with alkaline fixer. Its effect on fixer pH is very small. No more stains and it's quicker than a long water rinse.

bwrules · May 1, 2011

Thanks. Appreciate the info.

Photo Engineer · May 1, 2011

Use a running water stop for film or an acid stop bath.

Use an acid stop bath for paper.

Do not turn on any room lights until the fix step is complete.

This same applies to TF-5.

PE

bwrules · May 2, 2011

Thanks. What happens to a print if the lights are on midway through the fixing process?

Photo Engineer · May 2, 2011

An alkaline fix + alkaline developer carryover residue + some remaining Silver Halide + light = stain. A good stop bath or a good running water rinse will prevent or at least minimize this problem. I have seen it happen though in sloppy workflow or nearly exhausted chemistry.

PE

bwrules · May 2, 2011

Thanks PE. Will stains appear right away or as the print ages? Thanks.

Photo Engineer · May 2, 2011

It can do either depending on conditions in the coating.

PE

TF-4 and water stop, or lack thereof

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