RA4 without stop bath

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Originally Posted by Photo Engineer

Don't use a fix after the stop. Use the blix. The life will be longer and the results will be more constant, from print to print.

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I never had problems with consistency from print to print. And I really don't get how I could decrease BLIX life if I take out 50% of the Silver before.

polyglot: If you get RA4 BLIX for $2.50 per liter of working solution then there is certainly no point in preserving it. If, on the other hand, you spend $68 on a 5 liter RA4 kit, you tend to squeeze out every droplet of its chemistry and a cheap stop/fix bath is one step in that direction.

PS: I use a 30 second water wash step after my Agfa 304 stop/fix which prevents chemistry carryover from my stop/fix into the BLIX.

I got my 4x5L Kodak kits from Ag Photo in the UK; even with shipping it's going to be better than half the Freestyle price. Split the packs with a friend if necessary!

Rudi;

The OP wanted to speed up the process time. Using a separate fix and then a blix would increase process time. As for using a plain fix after development, (if that were the case) then the fix capacity would diminish by carryover.

A sequence of Dev, Stop, rinse?, Fix, rinse?, blix would be needed and that is just too long but it would increase blix life.

PE

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Originally Posted by Photo Engineer

As for using a plain fix after development, (if that were the case) then the fix capacity would diminish by carryover.

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I would assume that CD and fix alone would not work in RA4 since the developed Silver would remain in the paper ...

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Originally Posted by Photo Engineer

A sequence of Dev, Stop, rinse?, Fix, rinse?, blix would be needed and that is just too long but it would increase blix life.

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My current process sequence is CD, stop/fix, rinse, BLIX, rinse, wash. Final wash is done in a water basin, so the whole Jobo time is about 8 minutes. That's not too long IMHO and compares well to time spent on thinking about filtration/time changes, other preparation steps and exposure.

Polyglot, these prices for Kodak RA4 are almost too good to be true! Look at the sorry Tetenal kit on the same page, it's four times as expensive per liter working solution. Unbelievable ... :confused: Is there a difference in capacity per liter of working solution or something?

My total process through blix is 3 minutes at 100F and about 5' at 68F. The former in a Jobo and the latter in trays. The former also must have added to it a 30" 100F prewet.

PE

Kodak says you can omit the stop bath in RA-4 processing, but I have found that to be a very unwise procedure. Keep the stop bath. It only takes a few seconds. When I omitted it, I sometimes got all sorts of stains and blotches, which wasted both time and materials.

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Originally Posted by Photo Engineer

My total process through blix is 3 minutes at 100F and about 5' at 68F. The former in a Jobo and the latter in trays. The former also must have added to it a 30" 100F prewet.

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My process time is longer because I process at 30°C and that I use very conservative times for BLIX (2+ minutes).

Here is my time regime:

1. CD for 1:45
2. Stop/Fix for 1:15
3. water rinse for 0:30
4. BLIX for 2:00
5. rinse for 0:30
6. rinse for 0:30
7. rinse for 0:30

The Stop/Fix takes one minute longer than a Stop alone, but I assume that within 1:15 even a Sodium Thiosulfate/Ammonium Chloride based fixer removes most Silver Halides left after the CD step, thereby leaving only the developed Silver for the BLIX. The BLIX time is very conservative and even Tetenal's instructions call for only 1:00. The three rinses at the end not only ensure that I won't touch nasty chems with my bare hands when I open the tank, it also cleans the tubing within the Jobo so the next tank doesn't get left over BLIX with its CD. The Jobo is ready to go for the next tank!

With these processing steps I have seen color changes towards blue after processing many sheets of paper, and I would attribute these to exhausted CD. These color changes could be corrected through filtration but as they got worse with more sheets processed it turned into a futile catchup game. I never got poor D_min from exhausted BLIX, even in those sheets with extra blue cast.

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Originally Posted by Rudeofus

Polyglot, these prices for Kodak RA4 are almost too good to be true! Look at the sorry Tetenal kit on the same page, it's four times as expensive per liter working solution. Unbelievable ... :confused: Is there a difference in capacity per liter of working solution or something?

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I don't know the capacity of the Tetenal - I looked at the prices and went "duh, I know which I'm getting". The Kodak ones are packaged as 4 sets of bottles so you can make up 5L and keep the rest as concentrate (or sell them!) without opening. If anyone in Australia wants a Kodak 5L RA4 kit for $40, PM me as I still have one spare.

The Kodak requires about 10mL of replenishment per 8x10", so all up cost (with shipping) in AU is 8c/sheet. Certainly it's a good price, but it's not like the chemistry is inherently expensive (PtCl2!) or hard to make. And the shop is for real; they're an APUG advertiser and I've bought that very set of kits from them myself, as well as the Fuji C41 and E6 offerings.

PE: I think the stop/fix suggestion above was intended as replacement for a stop bath, not something to do between a stop and a blix. Since fixer is pretty acidic, it will act as stop and have the neat side effect of reducing silver load on the blix. Due to the high cost of (presumably B&W rapid) fixer vs acetic acid and the low price of RA4 blix as stated above, I don't see much point though.