Ra-4 development

jettmn · Jun 13, 2019

I was wondering the specifics when developing color prints and had a few questions. If i develop the paper in a tank do I agitate it like you do when developing film or just pour in the chemicals and let them do their work? Also do you guys recommend a stop bath and if you do what do you use? Would my ilfostop work as a stop bath or is that exclusively for black and white? Any help would be appreciated thanks.

koraks · Jun 13, 2019

I agitate paper continuously, whether it's B&W or color. An entire lack of agitation is likely to cause problems, especially with color.
I personally use a citric acid stop bath for RA4 these days and sometimes acetic acid. Despite that @Photo Engineer has said on this forum that for some (unknown to me) reason citric acid is not a good idea, I don't see any detrimental effects.

Rudeofus · Jun 13, 2019

The biggest advantage of rotary processing is the amount of chemistry needed. Unless you really only make tiny prints, filling up a large paper drum could easily mean several liters of process liquid. When I do RA-4, I start with 600-1000 ml color developer, which I reuse with no ill effects. RA-4 session ends, when developer loss by carryover got me down to 180ml of color developer, which is the minimum required for developing 8x10" sheets in my 2500 system drum. At this point I have done countless test prints and at least 5 good 8x10" prints.

Since in a rotary drum the chemicals touch only the bottom most part of the RA-4 paper, continuous agitation is a must. Another "must" is a stop bath between CD and BLIX, especially if you reuse a lot. Any stop bath will work, although PhotoEngineer recommends not to use Citric Acid based stop bathes, reason still unknown. You can use Acetic Acid or Sodium Metabisulfite.

Photo Engineer · Jun 13, 2019

And I am still trying to remember that reason regarding citric acid. I use 1% or 2% acetic acid.

PE

jettmn · Jun 13, 2019

How would you go about making the acetic acid or is there somewhere you could buy it like at BH?

Photo Engineer · Jun 13, 2019

Photographers Formulary also sells it and it may be even listed by Kodak.

PE

Rudeofus · Jun 13, 2019

I have heard, that food stores in the US/UK don't carry white vinegar in higher concentrations than 15%, if that. However, you can even use regular white vinegar (which is essentially Acetic Acid 5%) to make cheap and effective stop bathes safely.

MattKing · Jun 13, 2019

Photo Engineer said:
And I am still trying to remember that reason regarding citric acid. I use 1% or 2% acetic acid.

PE

Could it be anything to do with its propensity to permit mould growth?

BMbikerider · Jun 13, 2019

Photo Engineer said:
And I am still trying to remember that reason regarding citric acid. I use 1% or 2% acetic acid.

PE

The reason I don't use Citric acid stop baths is it has a propensity to form a 'woolly' type of fungus if not used for a while.

Photo Engineer · Jun 13, 2019

That I know. It can be prevented to a degree with the use of about 1-5 g/l of Benzoic Acid. That inhibits the molds.

That is not the reason I was told and none of my notes can back up my faulty memory.

PE

koraks · Jun 14, 2019

BMbikerider said:
The reason I don't use Citric acid stop baths is it has a propensity to form a 'woolly' type of fungus if not used for a while.

Yes, citric acid does grow 'clouds'. But I find it inconsequential; it's so cheap, just chuck it before this happens and mix some fresh.

Rudeofus said:
I have heard, that food stores in the US/UK don't carry white vinegar in higher concentrations than 15%, if that. However, you can even use regular white vinegar (which is essentially Acetic Acid 5%) to make cheap and effective stop bathes safely.

Here in mainland Europe I don't remember having come across anything more concentrated than about 9% in a supermarket, but I haven't looked very hard. Cleaning vinegar around here is generally 8-9% acetic acid so can be diluted 1+3 - 1+5 to get the 1-2% acetic acid stop @Photo Engineer mentions. Indeed, I do it this way whenever I use an acetic acid stop. For a one-shot stop bath (which I generally use for film development), I find that much lower concentrations than 1% are still effective. Buffering capacity is marginal at that point, but this doesn't matter for a one shot application. For repeated use, something in the 1-2% range generally lasts quite a while and is convenient.

lantau · Jun 14, 2019

In Germany, at least, you can buy Essence of Vinegar in most supermarkets. That is 20 or 25%.

I buy a 5L cannister of 60% acetic acid from Foto Impex. That's the cheapest and most convenient option for me. Some commenters on the Superfix thread on p.n will probably expect the German public soon being wiped out, because such dangerous material is available to everyone!

Oh, and I like the smell of both acetic acid and ammonia. No problem for me to use these.

koraks · Jun 14, 2019

Cost per mole of acetic acid is roughly similar for the 5l 60% adox product vs the cleaning vinegar I can get in the supermarket across the street (the latter being a bit cheaper if I buy 5l cans in the building supplies store). Either way, it's not going to break the bank.

lantau · Jun 14, 2019

koraks said:
Cost per mole of acetic acid is roughly similar for the 5l 60% adox product vs the cleaning vinegar I can get in the supermarket across the street (the latter being a bit cheaper if I buy 5l cans in the building supplies store). Either way, it's not going to break the bank.

Quite likely. Recently the supermarket in which I buy my lunch at work had a pallet full of the essence at a discount. But I like the 60% for convenience.

My Nova takes 1.8L of the 3% solution and while replenishing might be ok for b/w printing, when doing colour it is better to do a complete exchange frequently. The carried over developer makes a real mess and I had a feeling that it also degraded the image quality when the stuff became too dirty/used up. I went through my first 1L bottle rather quickly and the 5L will last a while, won't take up much space and is safely parked on my shelf.

But I used the essence for negative stop bath. my negative lab is my bathroom and I have the vinegar in the kitchen. If I need to make up solution right now I'll keep on using the kitchen stuff.

koraks · Jun 14, 2019

Carryover is quite a thing indeed. You don't want to know what my stop bath looks like when I discard it... The RA4 developer in the stop bath does work a bit like an indicator dye though. But the color shift happens only when the pH has gotten too high for my taste. I go by the old trick of feeling the surface of the print; if it doesn't get that coarse feel after 5-7 seconds, it's time for a new stop bath.

Raghu Kuvempunagar · Jun 14, 2019

Photo Engineer said:
And I am still trying to remember that reason regarding citric acid. I use 1% or 2% acetic acid.

PE

Citric acid stop bath can do weird things to C41 film. For example, with Ilford XP2 Super film, I get very dark coloured base, much different from the light pink coloured base I'm used to seeing when I use acetic acid stop bath. Maybe something to do with the dyes in the film. Don't know if this is the case with paper too.

mohmad khatab · Jun 14, 2019

I got the vinegar at 98% concentration - what is the dilution ratio for making a stop solution

afriman · Jun 14, 2019

mohmad khatab said:
I got the vinegar at 98% concentration - what is the dilution ratio for making a stop solution

At 98%, it's not vinegar but (almost) glacial acetic acid. In one of the posts above, PE recommends a 1-2% dilution.

Wayne · Jun 14, 2019

Photo Engineer said:
And I am still trying to remember that reason regarding citric acid. I use 1% or 2% acetic acid.

PE

I'm pretty sure you've mentioned it here, so when we create your brainchip from the archives we'll be able to recover it. But I can't remember it either...

DREW WILEY · Jun 15, 2019

I prewet, develop, then a weak acetic acid stop, followed by a brief plain water rinse, blix, then thorough final washing. I use the chem one-shot in drums. I mix just enough dev or blix for that particular day. Drums are also safer in terms of fume control than tanks of trays.

BMbikerider · Jun 15, 2019

Glacial acetic acid at the concentration of 98% is potentially very dangerous. It will easily remove skin and the vapours can affect those without 100% functioning lungs. Anyone with asthma will be especially affected

Even the Kodak Stop bath (The one you dilute to 1-63) is pretty vicious so please be careful - very careful

This is a quote from a Health and Safety document issued by the HSE in UK:-

Acetic Acid Hazards. Acetic acid can be a hazardous chemical if not used in a safe and appropriate manner. This liquid is highly corrosive to the skin and eyes and, because of this, must be handled with care.

Acetic acid can also be damaging to the internal organs if ingested or in the case of vapour inhalation.Acetic Acid Hazards. Acetic acid can be a hazardous chemical if not used in a safe and appropriate manner. This liquid is highly corrosive to the skin and eyes and, because of this, must be handled with extreme care. Acetic acid can also be damaging to the internal organs if ingested or in the case of vapour inhalation.

koraks · Jun 15, 2019

mohmad khatab said:
I got the vinegar at 98% concentration - what is the dilution ratio for making a stop solution

Something like 2ml to 100ml of water, or 20ml to 100ml water, etc.
Watch out with that stuff. And ALWAYS add the acid to water, not the other way around!! Take the necessary protective measures to prevent bodily harm.

pentaxuser · Jun 15, 2019

Photo Engineer said:
That is not the reason I was told and none of my notes can back up my faulty memory.

PE

It might be my faulty memory, PE but I feel sure you did mention the reason in some post or even posts in APUG/Photrio. Usually if someone says "just don't do something" and gives no reason that usually sticks in my head and I remember it in a negative fashion . However I don't having that kind of a negative feeling .

How you search for the right post is beyond me.

pentaxuser

Photo Engineer · Jun 15, 2019

I seem to remember posting it as well.

I do know that it can be used in a stabilizer after the Silver removal and the wash. The P122 stab. was Citric Acid at pH 4.5 or 3.5 depending on version, with additives.

EP3 was supposed to have one, but some bright guy removed it and the dye stability went south.

PE

pentaxuser · Jun 15, 2019

BMbikerider said:
Even the Kodak Stop bath (The one you dilute to 1-63) is pretty vicious so please be careful - very careful

I have the Kodak 1-63 version and can testify BMbikerider's advice. Avoid sniffing it straight from the concentrate i.e. lowering your nose over the opened bottle and breathing. One sniff may not and probably does not harm the lungs if you have no breathing problems but it does "catch your breath " unpleasantly. At its strength it is a long way from strong vinegar.

pentaxuser

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