washing 5x4 film in a 3010 tank

[Bruce Watson]

In an effort to track down some elusive crud that shows up on my 5x4 Tri-X, I'm going to run an experiment. The experiment is to process normally, but substitute steam distilled water for my normal city tap water. If the crud goes away, I'll have an idea where it was coming from and how to fix it maybe.

Anyway, my question is about washing film. I've read some about the Ilford research that says we typically wash film more than required for archival processing. They seem to suggest four or five water changes with continuous agitation - but all I can find talks about roll film in small tanks.

Has anyone tried this with a Jobo system? I'm using a CPP-2 with a 3010 tank. I'm thinking that maybe five water changes should be sufficient, with increasing times of 30 sec, then 1, 2, 4, and maybe 8 minutes. I'm thinking 500ml of water each change.

Is this insufficient? Is it overkill? Anyone have any light to shed on using a 3010 tank for film washing?

[Stan. Laurenson-Batten]

Hello Bruce.

I am using the same gear for 5X4. For washing I use filtered tap water for all but the last two washes when I use wash aid followed by a distilled water final wash.

Your washing time does seem a little short to me. Using my Cpp2 and the 3010 (5X4 and 3005 for 10X8) my total wash time is a little over half an hour with constant agitation and about six changes.
It may prove useful for you to know that for washing in the smaller Jobo drums I leave the tap water running slowly at the correct temp. I still give it the full half hour in the wash.
I am unable to do this in the large 3005 for 10X8 as the drum would get too heavy and the motor would stop, cut out or even burn out with overload. I enjoy sparkling negatives and trans. every time, with not even a trace of crud...

[Michael Gordon]

I wash in a 3010 with 500ml straight tap water per change. I do a total of eight washes (in minutes): 1,1,1,2,3,4,5, and 5. I finish with a Photo Flo dip. Seems to work just fine for me, and I'd rather wash too much than too little. I've never had any problem negatives.

[ronald moravec]

I`m going to suggest a few things you may already be doing. Keep going down the list until the problem is solved.

Do not reuse fix that has sat more than 8 hours or at least filter it with cotton in the bottom of a filter funnel or a quartered Bounty paper towel. Nothing works as well as Bounty and other brands do not work at all. Silver seems to precipitate from used fix and plants itself on the next film where it can be rubbed off, but not washed off, if not allowed to dry.

Filter all process solutions with as above including wash water.

Install a water filter for all process water. Calumet sells a good one. My sink is set up so both hot and cold water go thru the single filter, although the hot can bypass the filter if you open the hot tap. There are valves on both hot and cold lines and they join before coming out the spout. When hot and cold valves are open, the valve adjustment controls temp and the cold faucet controls volumn. Hot faucet is closed for this. Easier to set up than describe.

Remove everything from your darkroom and clean the entire inside with Swiffer towels or something that will pick up dust, not put in the air. This will include ceiling , floors, shelving, and countertops. Clean everything before it goes back in the same way. Use an air filter after you get it all clean. Filter the incoming air with an air filter for a furnace and spray it with sticky
"Filter Coat".

Examine your negs right after fix to see if the contamination is there at that stage as you progress down the list getting cleaner. You may be able to stop there.

Glass bottles can be cleaned much better than plastic and you can see if they are clean. Examine all solitions in a clear container before you use them.

If you do all this, you will get clean negs, but it may take some time to clean out all the water lines and get the bottles cleaned up. The inside of water pipes is filthy beyond belief.

[Ed Richards]

Be nice to have some data.:-) Washing has three variables:

1) leach rate - the time it takes to soak stuff out of what you are washing;

2) extraction rate - how efficiently are you draining out each rinse? If you drain out 99% of the water, at the end of the second rinse you are down to less 1/10000 of the original concentration. If you only get 90% out, you are at 1/100.

3) number of rinses

For Tmax, the emulsion is very thin, so the leach time cannot be very long, and the backing does not absorb anything. So my guess is that you do not need to rinse very long for each rinse, you just need to make sure you really drain out the water between rinses. I use a water rinse for a minute, a wash aid for a minute, then 3 more rinses for about 1-5 minutes, depending on what else I am doing, working hard to drain the tank each time. I have no idea if it is enough, but I am betting it is.

[Bruce Watson]

Ed,

I can't find the original Ilford publication online, but I'm sure it's out there somewhere. There's a similar paper (it's a PDF, so be forewarned) on this website here (http://largeformatphotography.info/unicolor/ilfwash.pdf).

I can paraphrase maybe, like this: Ilford found that, if everything is perfect, you can clean film in a single wash. Hypo in the film leaches into the wash water until an ion balance is reached where the concentration in the film is more or less the same as the concentration in the wash water. Since modern thin film emulsions carry very little hypo, and since the volume of wash water is typically large in comparison (3 or 4 orders of magnitude more volume than the emulsion), when equilibrium is reached the residual hypo in the film will typically be below archival standards. No, I'm not making this up.

All I can find is information about roll film in small tanks. But I infer that Ilford recommended filling the tank with fresh water, then making 5 inversions, dump, refill, 10 inversions, dump, refill, 20 inversions, dump and done. That is, three changes of water only. No wash aid. The reason for the three washes was, I think, your "extraction rate" because you can't get all the water to dump out of the tank/film/reel.

The theory seems sound, especially when you consider that washing is normally done "the way we've always done it" which dates to the thick emulsion days. Film is different now. Process should be different now too.

But... I can't find any data on doing this procedure on a Jobo. I'm thinking four washes because of the probably even lower "extraction rate" of dumping the water out of the 3010 tank.

Anyway, that's my theory. I just need more data to either back it up or debunk it.

[Ed Richards]

That squares with my back of the envelop calculation. I use a 3006 Jobo, but I use a Bessler base and not a Jobo machine. I just fill it, put it on the base and spin it for a minute, dump it and refill it. Since I dump it by hand, I am pretty sure the water is out, but I cannot speak for dumping it by machine. The Jobo should be more efficient than any other method because of the efficient mixing.

[Jim Ewins]

My last Chemistry class was 50 years ago. but I recall Bruce is spot on. But I don't reuse chemicals.

[Bruce Watson]

Ed,

Do you have any idea how using a hardening fixer would enter into the equation - if at all?

[Ed Richards]

I use a hardening fixer and assume that it makes no difference, esp. when you use a wash aid. I am not sure I need the wash aid, but I see it as belt and suspenders for my short wash times.