RA Developers

dslater · Nov 7, 2011

So,
After a several year hiatus from analog photography, I'm starting up my darkroom again. I used to use the Kodak RA-4 chemistry one shot kits for home use. Of course, these are no longer available, so I'll have to use a replenishing developer.
I generally mix smaller package size quantities and store the remaining concentrates in smaller bottles with no air space. This has worked well for me in the past.
I was planning to use Ektacolor RA Developer Replenisher RT 10L , however I also noticed there Adorama also offers Kodak RA Prime SP Paper Developer Replenisher 10L which has a single concentrate instead of 3. It is more expensive than RA-RT. However, the single concentrate makes for easier mixing.
So my question is does anyone know how the shelf life of the Prime SP concentrate compares to the RA-RT concentrate?

Mike Wilde · Nov 8, 2011

I don't have the answer, but there must be a good reason to store the constituents separately.

For RA-RT, I pack the CD agent, the B part in full small glass bottles, and thus the 10L kits last at least 3 years for me.

I make up the replenisher 1l at a time. 50mL A, 23mL B, 50mL C, and replenish the tank in my roller processor with 20mL per 8x10.

pinholer · Nov 8, 2011

I buy the 10 liter packages of RA-RT and dilute it straight from the concentrate for use in my Jobo. The formula I use is 250 ml water, 20 ml Part A, 8.9 ml Part B, 20 ml Part C, 12.5 ml Starter, and water to make 500 ml. Kept as the individual parts the shelf life is well over 2 years.

Mark Crabtree · Nov 8, 2011

I haven't used the Kodak, so don't know for certain that my experience will carry over, but other companies went to a single solution RA dev a number of years ago and I know folks with labs that used those. The ones they used were a thick concentrate that separated out into layers. I assume this is how the manufacturers managed to package it all into one solution and still have good keeping properties.

We did sometimes mix smaller quantities than the full bottle, but it would be something like 1/2 or 1/4 of the bottle, and a total of a couple gallons or more. I don't think small quantities would have been practical, and even worried a little about these partial amounts we used, but this would have been in replenished systems with about 4 gallon developer tanks, so small errors wouldn't be much of an issue.

dslater · Nov 9, 2011

Hey Mark,
That's really good to know. Given the single solution is so thick and separates, I'd agree that it probably isn't suitable for mixing small quantities. I think I'll stick with the RA-RT.

dslater · Nov 9, 2011

pinholer said:
I buy the 10 liter packages of RA-RT and dilute it straight from the concentrate for use in my Jobo. The formula I use is 250 ml water, 20 ml Part A, 8.9 ml Part B, 20 ml Part C, 12.5 ml Starter, and water to make 500 ml. Kept as the individual parts the shelf life is well over 2 years.

You only make up 500ml at a time? Are you using the dev as a one-shot, or do you recover & reuse the developer?

brucemuir · Nov 9, 2011

In my experience the RA-RT stuff lasts a loooong (8months-1yr) time either in concentrate or mixed to 1 litre.
I've seen others say this here also.

I reuse the tray solution until it's spent.

dslater · Nov 9, 2011

Yes,
But Greg & I use a Jobo for processing - not a tray. Since all the chemicals go in and out through the same drum, I'd be a bit concerned with cross-contamination as well as dilution do to water left behind in the drum after the pre-wet step.

Also, do you have to increase development time as you process prints through your tray, or does the dev time remain pretty consistent until the developer is spent?

pinholer · Nov 9, 2011

dslater said:
You only make up 500ml at a time? Are you using the dev as a one-shot, or do you recover & reuse the developer?

With 500ml I can process 10 8x10s in the Jobo using the chamistry as a one-shot. That is usually enough for an evenings printing. I have recovered it and continued to use it to process as many as 20 8x10s per 500ml. When I do this I use 2 prewets and develop and bleach fix for 50 sec plus a drain time of 10 seconds each. My stop is 1.5 oz of glacial acetic acid per gallon and I don't try to extend that. Because the solutions are becoming more exhausted, I use 200ml for the developer and bleach fix instead of the usual 100ml. The developer starts out the usual light beige color and becomes a dark blue as it is reused. After 20 8x10s it is almost black. That is where I stopped although I could probably go further since there was no change in either color balance or density.

brucemuir · Nov 9, 2011

It's fairly consistent.
I use a timer and the time depends on temp (room temp in trays) although I haven't found it all that critical.

With a JOBO it may exhaust quicker but I was mostly talking about keeping properties of the concentrate and mixed solutions.

I'll mix 1litre batches (sometimes have 2-3 on hand) so I have some fresh stuff if the 1st bottle goes while I'm printing. I store in FULL pet bottles and it amazes me how long it keeps.

dslater · Nov 9, 2011

pinholer said:
With 500ml I can process 10 8x10s in the Jobo using the chamistry as a one-shot. That is usually enough for an evenings printing. I have recovered it and continued to use it to process as many as 20 8x10s per 500ml. When I do this I use 2 prewets and develop and bleach fix for 50 sec plus a drain time of 10 seconds each. My stop is 1.5 oz of glacial acetic acid per gallon and I don't try to extend that. Because the solutions are becoming more exhausted, I use 200ml for the developer and bleach fix instead of the usual 100ml. The developer starts out the usual light beige color and becomes a dark blue as it is reused. After 20 8x10s it is almost black. That is where I stopped although I could probably go further since there was no change in either color balance or density.

Good to know - just curious, but why 2 prewets? And are you using the Jobo lift, or the magnetic covers?

Thanks

dslater · Nov 9, 2011

brucemuir said:
In my experience the RA-RT stuff lasts a loooong (8months-1yr) time either in concentrate or mixed to 1 litre.
I've seen others say this here also.

I reuse the tray solution until it's spent.

When you say mixed, do you mean a ready to use tank solution or just the developer replenisher minus the dev starter?

brucemuir · Nov 9, 2011

I'm using RA-RT in trays @ room temp so no starter is required.
No starter was suggested here on apug and I dont use it.

I also use a single prewet and a stop bath of acetic acid.

I mix 1 litre working solution from the 10l kit andstore in full PET 1 liter bottles with the air squeezed out.

dslater · Nov 9, 2011

Hmm - why no starter? Kodak recommends using starter to make a tank solution. Is it because you're developing at room temperature?

pinholer · Nov 9, 2011

dslater said:
Good to know - just curious, but why 2 prewets? And are you using the Jobo lift, or the magnetic covers?

Thanks

I decided to use two prewets in order to minimize the amount of "stuff" that would be carried over from the prewet and accumulate in the developer. My Jobo has the Jobo Lift. I also added some 1" PVC tubing to take the drainings to my sink which is to the right of the Jobo. When I save the developer and bleach fix I just have to take the Jobo drain hose out of the plastic tube and put it into the appropriate bottle which then goes back into its well.

brucemuir · Nov 9, 2011

dslater said:
Hmm - why no starter? Kodak recommends using starter to make a tank solution. Is it because you're developing at room temperature?

Yes, there's a thread here about it somewhere.
I rarely have success using the search function or I'd link you.

dslater · Nov 9, 2011

pinholer said:
I decided to use two prewets in order to minimize the amount of "stuff" that would be carried over from the prewet and accumulate in the developer. My Jobo has the Jobo Lift. I also added some 1" PVC tubing to take the drainings to my sink which is to the right of the Jobo. When I save the developer and bleach fix I just have to take the Jobo drain hose out of the plastic tube and put it into the appropriate bottle which then goes back into its well.

I see - makes sense. Which Jobo tube do you use to process your 8x10's? Also, once you've mixed some tank solution, do you re-bottle the remaining concentrate to minimize contact with the air?

Bob-D659 · Nov 10, 2011

I use the Kodak RA/RT 10 liter kits, and mix 2 liters at a time. I use a nitrogen purge on the stock bottles to remove the air. Mixed chems are in 2 liter soda bottles or 500ml water bottles with all the air squeezed out. I do room temp processing in drums, so no started is used for the developer.

Roger Cole · Nov 10, 2011

brucemuir said:
Yes, there's a thread here about it somewhere.
I rarely have success using the search function or I'd link you.

My understanding from previous threads is that the starter sort of "pre-ages" the developer for a replenished system, so it then can remain pretty consistent. For one shot use or use-until-exhausted in trays you don't need it.

Bruce, what paper are you using? The Fuji is far more readily available, at least fresh and pre-cut, but I've heard the results with room temperature in trays are more mixed than with Kodak Supra. I'd like to start doing this soon-ish, but would prefer to buy fresh paper in sheets if I can.

brucemuir · Nov 10, 2011

Roger Cole said:
My understanding from previous threads is that the starter sort of "pre-ages" the developer for a replenished system, so it then can remain pretty consistent. For one shot use or use-until-exhausted in trays you don't need it.

Bruce, what paper are you using? The Fuji is far more readily available, at least fresh and pre-cut, but I've heard the results with room temperature in trays are more mixed than with Kodak Supra. I'd like to start doing this soon-ish, but would prefer to buy fresh paper in sheets if I can.

I have a good stash of outdated Supra and maybe 2 boxes of Portra Endura left.
I also have a 600ft roll of Edge.
So all Kodak so far at room temp.

I haven't tried any Fuji yet but I was reading a recent thread and it sounded encouraging for some fuji types at room temp. I'll have to try it at some point.

Mark Crabtree · Nov 10, 2011

dslater said:
So,
After a several year hiatus from analog photography, I'm starting up my darkroom again. I used to use the Kodak RA-4 chemistry one shot kits for home use. Of course, these are no longer available, so I'll have to use a replenishing developer.
I generally mix smaller package size quantities and store the remaining concentrates in smaller bottles with no air space. This has worked well for me in the past.
I was planning to use Ektacolor RA Developer Replenisher RT 10L , however I also noticed there Adorama also offers Kodak RA Prime SP Paper Developer Replenisher 10L which has a single concentrate instead of 3. It is more expensive than RA-RT. However, the single concentrate makes for easier mixing.
So my question is does anyone know how the shelf life of the Prime SP concentrate compares to the RA-RT concentrate?

I started this post to clarify that my comment about the thickness and separating into layers of single mix RA dev repl concentrate was about other brands. I suspect Kodak approached it the same way, but it would be worth checking. I'm not sure but think it was Fuji and Trebla (or Champion) my experience was with.

Now I also see that I may have misunderstood your original post. I thought you were mixing partial quantities from the mix bottles, but as I read it again it sounds like you are mixing the full bottle, then storing the mixed solution in multiple smaller bottles. The issue I spoke of in mixing partial amounts wouldn't be an issue in that situation.

pinholer · Nov 10, 2011

dslater said:
I see - makes sense. Which Jobo tube do you use to process your 8x10's? Also, once you've mixed some tank solution, do you re-bottle the remaining concentrate to minimize contact with the air?

I usually use the 2830 tank and process two 8x10s at a time although I have a 1520+30 tank that handles a single sheet and uses half the chemistry of the 2830. I keep the unmixed concentrates in the original bottles. My experience has been that the bleach-fix concentrate will go bad before the developer concentrate. When the mixed bleach-fix looks puny (thats a technical term for looking pale and weak) I know that it is on its last leg and that I should get some fresh bleach-fix. Right now I am using concentrates that I got in Feb 2010 and they are working fine.

pinholer · Nov 10, 2011

Mark Crabtree said:
Now I also see that I may have misunderstood your original post. I thought you were mixing partial quantities from the mix bottles, but as I read it again it sounds like you are mixing the full bottle, then storing the mixed solution in multiple smaller bottles.

I too mixed up the entire 10 liters and stored them in brown glass bottles of various sizes for more than a few years. When I noticed that they could go bad before I got them used up I started mixing them in small quantities straight from the concentrates. That solved the problem as long as I use the bottle of concentrate up within 2 years or so. It also reduces the amount of space under the sink that I used to store the chemistry. Of course that space fills up with other things.

DREW WILEY · Nov 10, 2011

I always mix the RA/RT per daily session, or even per print. That has pretty much ended any questions of predictability,
provided one isn't down to the last bit of concentrate and has temp under control. Never had much luck with other brands, but haven't tried some of the more recent options either. If Kodak tanks, someone will still provide high quality RA4 chem, because it's essential for both traditional dkrm use and all the digital laser printers like Lightjet. My only question at this point is whether to install a 40" roller processor instead of using drums. And unfortunately, it's the kind of gamble that depends on the continued availability of 8x10 color neg film and matching C41 service. The good new is that at the moment, Fuji seems to be stocking more roll sizes of Supergloss in the latest CA II.

dslater · Nov 10, 2011

Mark Crabtree said:
I started this post to clarify that my comment about the thickness and separating into layers of single mix RA dev repl concentrate was about other brands. I suspect Kodak approached it the same way, but it would be worth checking. I'm not sure but think it was Fuji and Trebla (or Champion) my experience was with.

Now I also see that I may have misunderstood your original post. I thought you were mixing partial quantities from the mix bottles, but as I read it again it sounds like you are mixing the full bottle, then storing the mixed solution in multiple smaller bottles. The issue I spoke of in mixing partial amounts wouldn't be an issue in that situation.

No - you read it right - I mix partial quantities.

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