black and white in a roller transport - which chemistry
I have a ton of b/w rc prints to make and so I'm considering running the prints through my fujimoto roller transport machine. Does anyone have any experience with this? Does chemistry dedicated to rt work better than others? Is a stop bath necessary? I'm considering Ilford's 2150 kit but noticed that other b/w developers have working temps between 65 and 90 degrees f. Also, I'd like to use a hardner with the fix to keep scratches down to a minimum. Unfortunately the 2150 fix is hardner free. This makes me wonder whether hardner has an adverse effect on the hardner.
I have a Durst Printo with only two baths plus the intro unit, normally I run RA4 colour through it.
A couple of years ago I had to make over 500 8x10 B&W prints from the same negative.
I used what I had on hand which was Ilford multigrade developer and fix.
I ran the baths at 30C and exposed so that I got a working system with the unit running at the RA4 speed, instead of the slower 1 minute B&W speed.
The Printo unit has squeegee exit rollers so carry over of solutions is virtually non-existent, although the emulsion obviously carries developer through to the fix.
Once I was up and running I just had to watch out for solution exhaustion, this was done by counting the amount of sheets running through.
Having already pre-mixed the dev solution, I could drop the bath, re-load with fresh chemicals an inside 15 minutes it was up to 30C and ready to roll again.
I have an RC paper dryer so drying was done after a two bath step manual wash. I had an assistant for the day and I remember that we took about 3 hours for the whole job. It was a nice little earner which paid for all of my film for the next year and a bit.
I've used my CP-31 for B&W
The way I do it is to run tank 1 as a water bath to soften the gelatin. I know that it is supposed to be the dev tank, but mine has the digital thermostat in a DOA state, and I have klugded an analog thermocouple to allow me to run it to within a degree or so of the desired set point.
I do this with RA-4 also - some of the older supra has a blue dye that comes off in this bath, so it doesn't give the developer more organic stuff to oxidize off and die faster.
Tank 2 I feed 1:2 agfa100/dektol/d72 generic cold tone developer. I never expect it to last past one session; With the roller transport and a big printing session you can almost exhaust the 2l of chems with the number of prints thst you can feed through it; I have no replenisher unit and I do ok. At the end of the night the developer is very dark, and gets tossed. If I ran B&W more, I would look to an RT designed developer, that would be more resistant to the aerial oxidation that the rollers give.
There is very little carry over between my tanks. If it has been a short session, I might tweak the pH of the fixer back down with a bit if acetic acid to counter for whatever alkaline influence the dveloper carry over levels impart. Most of the time the stuff is close to exhaustion, and I relegate it to a wait for some contact sheets in a tray use before it goes off to the HHW depot.
Tank 3 I feed with PE's home brewed superfix. Formulary TF-4 would likely work here as well. Hot, this potent fixer has the paper fixed in under the 45seconds it spends in the bath.
I disconnect the wash dry unit and wash the prints in a vertical rocker washer, then hang to dry, then lay on fibreglass screens. I don't trust the wash tank in giving a sufficient wash to get the hypo levels down, but then again I have never bothered to check; maybe I should becuase the way I do it now is certainly more work.
Other different ways to use a roller- accrue the dud B&W prints, and wash and dry them from any session you do - tray or roller, and then use then as el cheapo clean out sheets at the beginning of a session.
If you wash them between uses, you can also use RC paper as a 'carrier' to do B&W fibre paper in your roller. Wet the exposed fibre paper for a minute to soften it, paste it to a piece of larger otherwise scrap RC paper , and feed it into the machine. Don't feed them into the W/D module. At the end of a session, do a bulk fixer 2 pass with the accrued session's output, then wash ,and dry as you would a tray processed fibre print. It is still a lot faster than hand printing a big fibre job. The hot developer, and pre-wet emulsion gives you all the d-max that you are looking for in 45 seconds.
If you are getting fogged highlights, dial back the temperture of the developer tank.
Ilford used to make a high-volume roller transport processor for RC b/w paper that was used extensively by large labs for custom b/w printing. It is not at all difficult to use any roller transport processor originally designed for RA-4, or EP-2 for b/w, you just adjust the strength of your developer and fix to accomplish completion in the time the paper stays in each solution.
Thanks to Mike and Mick for relating their experiences. The fb trick is extremely interesting. I assume you're using scotch tape to adhere the fb sheet to the rc "carrier" right?
I did some research online re: developers for rt b/w and it appears as though Ilford is the only company making dedicated chemistry for RT. There's the 2150 kit (3 litres) designed specifically for the machine PHOTOTONE refers to above (which I'm pretty sure does not have automatic replenishment) and then there's the 2000 rt chemistry which is referred to as "replenisher" chem. I did not find any reference to replenishment rates for the former and so am assuming that it's meant to be used to exhaustion and will work fine as long as SG is where it should be. I'm not too concerned about whether or not using rt for b/w will work (how could it not?) but I am keen on using chem. designed specifically for RT only because I have A LOT of prints to make (like several thousand) and consistency in print color and development activity is critical. While lots of b/w chemistry claims working temperatures up to 30 c. only the two ilford types are advertised specifically for rt. My main concern is the lack of hardner in the ilford rt fix. There must be a reason for this. Either hardner is bad for the machines rollers or hardner is simply not meant to be used at high temp. Any info would be much appreciated.
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If a hardener were used in the Fix, the wash time would have to be extended, thus somewhat negating the "fast" dry-to-dry concept behind the Ilford system.
Originally Posted by frotog
Fast develop, fast fix, fast wash following by drying. These machines delivered fully fixed and washed and dried prints in just moments. (relatively)...and at high volume. I do believe the Ilford RT processors DID replenish.
fb - no tape
the fb sticks to the rc carrier due to the capilliary action since the fb print is already wet