There is some talk now that it may be better to not totally wash all the fixer out of the prints. There is some thought that thiosulfate may actually help protect the paper from outgassing and the like. I am not up on it totally and I am not sure I believe it but I have had one print go bad in 35 years of fiber base printing.
In my new darkroom I will have two archival washers and a washing machine (zone6) that is sort of a holding tank for prints. I am gonna make a tray to fit into the washing machine to wash 4x5 and 5x7 negs.
Isn't this just one more example of the trade offs in everything? By soaking you're trying to use the least amount of water. If 5 changes is all that's required why not just use 5 trays? The first tray would end up with the max amount of hypo. All the way down to the last try which would be much cleaner. Lots of trays but cheaper then even the 5x7 washer.
I LOVE this thread. It should be called Everything You Always Wanted To Know About Archival Print Washing.
So here's my question...if you tray wash (and I like the idea of the tray with holes), how many prints can you have in the tray? Do prints touching each other stop, reverse, or severly hamper the diffusion/leaching process? Let's say we're talking about 8x10 prints in a 16x20 or 20x24 tray.
For 8x10 and 11x14 I use a home made washer that consists of a fish tank with lexan partitions and holes drilled in the bottom to allow a slow drain and a rubber hose that runs from the faucet and has five brass nipples that empty water into each compartment. Two prints per slot, 5 slots all together.
I also have used several of the el cheapo plastic trays, 11x14 size for 8x10. I would put 4 prints in each tray and change water at ten minute intervals for 50 min. During the ten minutes i would agitate or rotate the prints top to bottom. Now I use the trays with holes and just let it run for 40 minutes after HCA.
Trays work fine, the disadvantage is you have to be there every ten or fifteen minutes to change the water or move the prints to a fresh tray. "Archival" washers have the advantage of turning it on and going about your other business, but wasteful of water.
An excellent series of articles on this subject can be found in "Black and White Enthusiast" magazine.
Tim Ruddman wrote all three articles. He did mention that leaving a trace amount of fixer in the print was beneficial for longevity of the print.
If you decide to tray wash, I would do a test for residual hypo to test if the prints are washing adequately. I would think prints that come in contact with each other continuously would take longer to wash. Just taking a WAG.
It seems to me that critical here is the amount time in the water.
As everyone knows: TEST, TEST, TEST!!!
In one of Bruce Barnbum's book, he discusses using a series of trays, moving the prints from tray to tray. If I remember correctly, he soaks each print for 10 minutes in each tray moving prints from tray to tray. I will look this up tonight when i go in for my class.