Kodak RA/RT Usage Advice (Replenishment)

Bumba · Jan 7, 2020

I just want to post my measurements for part mixing in case someone in the future needs this information to split their chemicals. They also say to stir for 2 mins after adding each part.

Kodak RA-4 RT/LU (4x5L kit):

Developer

Part A - 250ml (just over)
Part B - 120ml
Part C - 250ml (just over)

1L = 750ml (water) + 50ml (part A with a touch extra) + 24ml (part B) + 50ml (part C with a touch extra) + 125ml (water)

Blix

Part A - 710ml
Part B - 1L

1L = 500ml (water) + 142ml (part A) + 200ml (part B) + 158ml (water)

Just hope this helps some in the future

Bumba · Jan 7, 2020

One more thing before I forget. I usually use a 2% vinegar stop bath then rinse before blix which I then reuse. Would using a 1% stop cause any problems? I use it one shot normally. Just wondering if I could stretch it a bit further without negative effects.

Thanks

koraks · Jan 7, 2020

For one shot 1% would likely be perfectly fine. Even 0.5% would probably be still OK. Measure with a pH meter before discarding some used stop bath; as long as it is still below something like 4.5 is would be OK.

Bumba · Jan 7, 2020

Ok thanks Koraks I'll give the 1% a try.

I've run into a problem (some of you may think I'm an idiot). I just finished mixing everything up and put away then one of the glass bottles I'm storing my blix explodes. I'm using flip top Kilner bottles (like Grolsch bottles). I think it's because I filled it all the way to the top with literally no air.

Should I have left a little air pocket at the top to reduce pressure? Also would plastic bottles be better as I can get rid of all the air and not worry about the thing exploding?

Thanks

koraks · Jan 7, 2020

I've never had bottles exploding, but maybe it's because your chemistry was warm when you filled the bottle, it then cooled off and shrunk, making the bottle implode? I'm surprised that the kind of bottle you used did that; I've never had this happen myself.

Bumba · Jan 7, 2020

Yeah was very unexpected and confusing as I watched my blix pouring away haha. Not sure what happened because it's a very sturdy bottle. Do you fill your glass bottles with any air pocket Koraks?

koraks · Jan 7, 2020

No, I try to leave as little air in the bottles as possible. Preferably none at all. But I do my RA4 at room temperature so there's no contraction or expansion going on. But I haven't had this with C41 chemistry either, which I do use at 38C.

Bumba · Jan 7, 2020

Oh OK. I think it's just me because I am exceptionally unlucky in life haha

Bumba · Jan 8, 2020

Sorry but I'm back again. Just a quick question. If I'm replenishing my blix do I need to extend my blix time also? Or should I keep it the same as development time?

Thanks

koraks · Jan 9, 2020

With proper replenishment Blix time remains the same.

Bikerider · Jan 9, 2020

Bumba said:
Hi, I've searched high and low to get as much information on this kit as possible but I've got some questions left.

I know many of you use it as a room temperature developer. I'm planning on using it in drums but I'm in the UK so the kit costs a fair bit (think it's probably cheaper in America). It's costing £120 for both the dev and blix 20l kits. I would like to use it as a replenished system if possible. I searched through the Kodak documents and got roughly a value of 14ml per 10x12 (10ml per 8x10) but this seems a bit low to me. I was thinking more along the lines of 40ml which is 1/3 of what my drum requires. Does anyone have any advice for a replenishment system?

Also are these chemicals best used at room temp or higher temp. I'd prefer to use it at room temp but it's not much issue heating them up if it increases the image quality.

Thanks for any help
Bumba

The suggestion of 10cc per each sheet (equivalent) of paper is spot on. I use a NOVA deep tank processor and that is the replenishment rate I have used since 1991. OF course with a NOVA you have the reservoir of approx. 2 litres to start off with but I have kept the same developer working with the replenishment suggested for over 12 months. I only changed it when I had to clean out the tank to get rid of the staining and sludge build up. The replenishment of the BLIX is also done at the same rate as well. With the stop bath, the indicator type is useless because it changes colour to dark brown very quickly and the indicator cannot be seen so that also gets replenished but at 15cc per 10x8 sheet. (Stop bath is comparatively cheap compared to the dev & blix)

I have never seen an official guide from Kodak for using the Kodak developer/blix at any other temperature than 35c so that is what I stick with, Using it at a lower temperature in a drum you then possibly run the risk of a greater temperature variation than the 35c because you will have to extend the development time to well over the optimum 45 seconds.

Tom Kershaw · Jan 9, 2020

Bikerider said:
Recently I have been using Tetenal RA4 and to be honest I personally find it NOT to be as good as the Kodak. I only used it because the Kodak was in short supply. It has been suggested to me that the Tetenal already contains the starter or the equivalent and that does not give the longevity which is the hallmark of Kodak. I have had to ditch the last lot because it went stale despite adequate replen. By longevity I mean replenished exactly as suggested by Kodak. I have used the Ektacolor RA4 in a deep tank for over a year and only changed it to let me get rid of the sludge build up!

The Tetenal RA4 4x1L developer concentrate package doesn't contain a starter. It dilutes to make a replenisher at 1+9 or can be diluted 1+19 for one-shot use in a drum (without a starter). The starter is a separate product. e.g. 500ml replenisher + 50ml starter + 450ml water...

Bumba · Jan 9, 2020

Thanks for the help everyone. I've just made my first test strip with these chemicals. At first glance the blacks and contrast don't look too good but I'll have a proper look when it's dry.

I did 2 mins time but my chemicals were a couple degrees under 20 degrees so maybe I need to store them somewhere warmer.

koraks · Jan 9, 2020

I do RA4 at whatever temperature my darkroom (and the chemistry) happens to be; currently that's around 16-17C. Development time is always 1m30s and that has proven to be just right across the entire range of temperatures I've been confronted with, which would be something like 15 to 25C. Turns out the temperature is not very critical as long as development time is sufficient. If 2 minutes is still too short I suspect you may have an issue with the chemistry. You may want to chuck a test strip into the developer with the lights on so you can see what happens and get a feeling for how fast development is progressing. It should be pretty rapid.
If you don't already have one, I strongly suggest getting a pH meter so you can monitor pH of the developer. I find it tends to wander a bit (towards lower values) in an old and frequently used + replenished developer.
For quick checking of results a hair dryer is uite convenient allowing you to dry your test strips in a few seconds. Depending on the paper used contrast and color will shift during dry down; the difference is rather extreme in Kodak Endura and a little less so (but still apparent) in Fuji Crystal Archive.

mshchem · Jan 9, 2020

RA4 is an amazing process. I always laugh at how Kodak still defines critical temperature control. Fuji publishes times for processing at higher temps where development times are very short. I've found as long as you develop to completion temperature is irrelevant (I've never processed at room temperature )
I have Jobo machines, but for color printing I still use the famous (infamous) Kodak Rapid Color Processors, model 11 and 16k. These beasts are antique but great machines. I still process at 38°C , this goes back to the 1960's/70's era CP5 chemistry. I can have a print through quickly. By definition the process starts with a brief pre-wet in a tray before it goes on the machine. 30s Developer, 15s stop bath (ordinary Kodak stop bath indicator is ok), 30s blix, followed by 1min 30s wash. No stabilizer (a final stabilizer of 30 seconds is a good idea if you want to protect the print from fungus etc. I've never had a problem with out).
All this is done in the dark, no daylight drums to clean. For decades I've had a microwave to warm chemistry.
A super easy way is to make up a liter of developer, stop and blix. Get all 3 in the Kodak plastic graduates, heat the up to 105°F /110°F. Use one tray. Pour enough chemistry to work the print, go 35-45s with each solution just pour in and out of the single tray.
Color printing is so much less complicated than black and white. Stick with one film and Fuji Crystal Archive cut sheets, easy as pie.
Look at this wonderful site, the romance of the analogue world!

https://www.photomemorabilia.co.uk/index.html

Bumba · Jan 9, 2020

Ok people this is what I've come back with from today and thanks for the past advice.

Both tests made with the same chemicals, filtration, time, f stop etc. They're identical apart from the processing. The one on the left was processed at 2 mins @ just under 20°c. The one on the right was processed at 45s @ 35°c (went in 35°c, came out at 31°c). The strip at the bottom was exposed to room light then developed at 20°c @ 2 mins and it took 20-25s to turn full black.

It doesn't show the difference between the two so well on the scan but it's more pronounced in real life. The density of the room temp one is lacking and the image lacks the punch and vibrance of the 35°c.

What do you guys think? Should I process longer at room temp or do a longer exposure of the test strip.

Bumba · Jan 9, 2020

Just looked at the Kodak datasheet. I might try a 3 min dev time at 20°c with intermittent agitation and see if that gives me better density

mshchem · Jan 9, 2020

You can't "over develop" RA4, but you can under develop. I would use warmer chemistry. It's faster. I run everything at 100°F. Pre wet won't hurt anything. What I did with the Ilfochrome (Cibachrome) was semi one shot. I would use 120 mL for an 11 X14 tube, I would save the used developer, and for the next print I would use 60mL of fresh developer and 60mL of the used from the previous run. Worked great. I think this would work with any tube processor.
I used a 12 liter plastic bin with a aquarium heater, I would float the 1 liter bottles of chemistry in the bath to keep warm. (Start with really hot water 45°C, this will warm your bottles fast) your times will drop dramatically even at 85F.
The old P122 process was 12 minutes 1st developer @75F, 6 minutes @85F.
There are tray warmers if you want to use a tray. Still if you are not in a hurry 20°C will work fine.

NortheastPhotographic · Jan 9, 2020

mshchem said:
You can't "over develop" RA4, but you can under develop. I would use warmer chemistry. It's faster. I run everything at 100°F. Pre wet won't hurt anything. What I did with the Ilfochrome (Cibachrome) was semi one shot. I would use 120 mL for an 11 X14 tube, I would save the used developer, and for the next print I would use 60mL of fresh developer and 60mL of the used from the previous run. Worked great. I think this would work with any tube processor.
I used a 12 liter plastic bin with a aquarium heater, I would float the 1 liter bottles of chemistry in the bath to keep warm. (Start with really hot water 45°C, this will warm your bottles fast) your times will drop dramatically even at 85F.
The old P122 process was 12 minutes 1st developer @75F, 6 minutes @85F.
There are tray warmers if you want to use a tray. Still if you are not in a hurry 20°C will work fine.

What is the purpose of the stop bath if the paper is processed to completion? Why not simply use a water bath or go straight to the BLIX. My V30 just goes dev, bleach, fix. No need for a stop bath or even a water bath.

mshchem · Jan 9, 2020

NortheastPhotographic said:
What is the purpose of the stop bath if the paper is processed to completion? Why not simply use a water bath or go straight to the BLIX. My V30 just goes dev, bleach, fix. No need for a stop bath or even a water bath.

I have always used stop, it's in the workflow recommended by Kodak for my old processors. It's supposed to help prevent stains. I'm not sure it's necessary, but old habits die hard. . Clearly when minilabs process roll paper continuously the paper goes through developer, blix 1, blix 2, then 3 counter current stabilizer baths, then through the dryer. No stop, no wash. When you are using tubes or drums the chemistry volumes are so low. I agree that water would probably do just fine or maybe just go straight into the blix. It's just my way. Best Regards Mike.

koraks · Jan 10, 2020

@Bumba the left strip is indeed underdeveloped. I'm surprised at this as I get full development in 1m30s with fuji developer at less than 20C.

A stop bath is a good idea if you use a replenished Blix. If it's one shot, might as well skip stop.

btaylor · Jan 10, 2020

Regarding stop bath- roller transport machines squeegee the paper between dev and fix, reducing carryover. Many years ago when using tubes I think I would use a water rinse between the two- worked fine.

Bumba · Jan 10, 2020

Little update from today. Made two new identical test strips. One I processed for 3 mins at room temp and the other I used 60ml (usually use 40ml) for 2 mins at room temp. Neither of these had very good density and I can't get close to the heated chemical density.

I am using drums so maybe this kit is better for trays. I may have to work out an easy system of heating up chemicals without a jobo.

1) Chemicals at 35°c
2) 60ml/20°c/2 mins
3) 20°c/3 mins
4) 20°c/2 mins

koraks · Jan 10, 2020

Yeah, that doesn't look too good. I can't comment on a Jobo situation, but 60ml sounds like a rather small amount for a print drum. Then again, it works for you at 35C. Do you currently replenish the developer? So that the 60ml volume you use is in fact a small bit taken from a larger vessel containing the replenished developer and you return the 60ml to the rest after developing a strip/print?

In my room temperature setup I use 500-600ml in a tray. The tray holds up to 24x30cm prints but a larger and flatter tray would easily develop larger prints with the same chemistry volume. I find working with small/minimal amounts of chemistry to be tricky as there's very little capacity to protect against any variations such as oxidation etc. I'd rather have a bit more volume to buffer with. But I'm kind of addicted to trays, I have to confess. Didn't like the hassle print drums brought along, but that's rather personal.

For keeping your developer up to temperature you could consider one of them nifty sous-vide cooker thingies. I hear good things about them.

Bumba · Jan 10, 2020

Yeah I'm a bit stumped because these were all made with fresh chemistry. Only put 3/4 of a sheet through. I'm going to take a few days to do some research on chemical heating ideas. It wouldn't be such a problem but I process in the bathroom and there are no plugs in there.

I've tried 35°c before but the short times made it too difficult by hand. I may have to find a temp that has longer times and less drift than higher temps.

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