Confused about kodak RA4 chemicals

[polyglot]

RA4 developer stock lasts for months and months and months and months after being mixed up as long as it's in an air-free container like a mylar bag. I think I was using a 5L batch (replenishing a 400mL working solution that lived in a coke bottle) for nearly a year without problems.

 

[zehner21]

RA4 developer stock lasts for months and months and months and months after being mixed up as long as it's in an air-free container like a mylar bag. I think I was using a 5L batch (replenishing a 400mL working solution that lived in a coke bottle) for nearly a year without problems.

Alternatively, I use glass bottles like the old ones used for bottling beer. They have a rubber band around the cap, so air exchange does not occur.

 

[David Lyga]

For anyone new to RA4 colour processing, one of the key differences over black and white chemicals, is the shelf life - even when mixed up RA4 chemicals can last up to 6 weeks as long as they are in air tight fully filled containers

I am sorry to contradict you, Devon, but I mixed some Kodak gallon size RA-4 developer back in 2003 and wanted to see how long it would last in 'filled to the brim' PET plastic. Through the years I have tested it. I am STILL using it and it shows NO sign of deterioration. It is JUST as potent now as it was 12 years ago. - David Lyga

 

[markd514]

You do not need the stabilizer.

The Kodak RA/RT replenisher can be used at room temperature, about 68-75F and I use it this way in trays. Much easier than heating up to temperature, you don't have to waste time washing and drying a drum, and small test prints are easy to make. I don't use a safelight. Working in the dark is easy to get use to. Make sure your safelight is safe for color negative papers. I used a drum many years ago but after switching to trays my productivity increased significantly. If the chemical fumes annoy you, ventilate adequately.

I just cant see (no pun intended) sticking tongs into a tray to remove paper in total darkness

 

[markd514]

I agree, those are chemicals that I would not want to be dipping my hands in.

 

[RPC]

I use my fingers. After each print, I rinse them thoroughly. Then, at the end of the printing session I wash my hands thoroughly with soap and water and then rinse well. I have never had a problem. But that's me. Some may develop a sensitivity to the chemicals but I am lucky and never have. If you fear these chemicals, then you can do like PE says and wear rubber gloves. I don't think color chemicals are any more problematic to handle than b&w, and they have been used in trays by many for years.

 

[Wayne]

and if you fear gloves, you can snip the fingers off and just use those...

 

[Roger Cole]

I don't "fear" gloves but I can't really do anything worth a damn with my fingertips covered. Even in winter, and I'm someone who HATES cold weather, if I'm wearing gloves it probably means it's cold enough my fingers might shatter otherwise (which fortunately means in Georgia I almost never wear gloves.) I do occasionally wear fingerless ones to keep my hands warmer but that's pretty useless for this.

I'm ok with tongs and a very dim safelight.

 

[markd514]

I am definitely going to try the dim safelight and trays.

 

[Wayne]

The problem I've has with snipping fingers off of nitrile gloves is that I always manage to get something inside the finger anyway, rendering it pointless. And I've never tried it with color because I've never developed color in trays. Just an idea for the super-careful.

 

[Photo Engineer]

You can get wet spots on gloves that you cannot feel and therefore you do not dry them properly and end up leaving water spots on the print.

PE

 

[DREW WILEY]

I mix only enough RA4 chem for one day's session at the most. Unless you are skilled at replenishment or can truly keep air out of a bottle for a few extra days, it seems to make a noticeable difference; and for this reason, it might well explain why some people have so much
trouble fine-tuning color balance. The unmixed concentrates last a long time, with the "B' component to the developer going bad first,
evidenced by brown discoloration. Otherwise, putting bare skin into any of this stuff seems like being a snake handler and bragging that you've never gotten bit yet.

 

[hgaude]

I'm always amazed at the differing views of the hazard of hands in color chemicals. Though I've never done it, but am keen on giving it a go, if I could use my fingers in the trays, the darkness aspect wouldn't be an issue at all and would be vastly simpler than tanks since the times are so short and so fixed.

 

[DREW WILEY]

There might be differing views via casual web chatter concerning safety. But there are certain minimum requirements to any MSDS sheet,
which are required by law and should be read by anyone handling any kind of chemical product. But "artistes" always seem to think they're
own "art" is so meaningful that their personal health is a negotiable asset. Viewpoints change as people get older and they wish they could take things back. Man, have I ever seen some really messed up people over the years, including folks who got careless with color photo chem. And nitrile gloves are so damn inexpensive.... Kinda like smokin'. Roll the dice if you must, but don't go around preaching it's safe.

 

[Photo Engineer]

The smelly stuff is the preservative. It is a derivative of hydroxyl amine.

I have kept developer for up to 6 months in a full closed plastic Jobo bottle. In glass, storage time would probably double.

I use RA-RT Developer Replenisher with NO Starter. It will work from 20C to 40C or 68F to 100F (rounding numbers for Purists who have contacted me with notes to the effect that 40C is not 100F - I KNOW THAT, I am rounding for the ones who don't care to be precise to the nearest 0.0000001 deg )

I use 2' at 20C and 1' at 100F (howzzat for mixed units).

PE

 

[Roger Cole]

The smelly stuff is the preservative. It is a derivative of hydroxyl amine.

I have kept developer for up to 6 months in a full closed plastic Jobo bottle. In glass, storage time would probably double.

I use RA-RT Developer Replenisher with NO Starter. It will work from 20C to 40C or 68F to 100F (rounding numbers for Purists who have contacted me with notes to the effect that 40C is not 100F - I KNOW THAT, I am rounding for the ones who don't care to be precise to the nearest 0.0000001 deg )

I use 2' at 20C and 1' at 100F (howzzat for mixed units).

PE

Is the time/temperature relation pretty much a straight line? That is, can I just graph out 2:00/20C to 1:00/40C and derive a time for whatever I have for ambient?

Heck, no graph needed if it's linear. That's one minute for 20 degrees C variation so if my solutions are, say, 24C (not unusual in summer, sometimes a bit more) that would be two minutes less 12 seconds or 1:48, call it 1:50?

 

[Photo Engineer]

Roger, I was so happy things worked out this way I didn't do any more than the 2 points. My DR is about 68 - 70 F all year round.

Humidity is what varies. It is very low now and very high in summer.

PE

 

[Roger Cole]

My DR is in my basement, and currently still without plumbing so I use a holding bath and take prints and film upstairs to wash (hopefully, maybe, this coming year for the plumbing and a downstairs bathroom!) This is one reason I haven't gotten back into color. B&W is a bit of an annoyance but not too bad working this way. Color is more so. It is a "daylight" basement (house is on a side hill) so rooms along the back of the house, including the current darkroom, have windows (blacked out of course) but are still partially underground. The temperature, if unheated in winter, varies from the mid to upper 50s in winter to upper 70s in summer (no AC down there, nor does it really get hot enough to need it for someone like me who's pretty comfortable even at 78 if dressed accordingly.)

Hopefully at some point in the coming year I'll give color another go and I'll let you know.

 

[DREW WILEY]

I've always suspected that amines were only of the ingredients in color chem that are particularly prone to inducing sensitivity. That is certainly the case in the epoxy industry, where workers sometimes go outright anaphylactic. I was growing impatient with some epoxy filler on the darkroom floor last nite, which is curing a bit slowly due to cold temperatures. So I took a heat gun to it; and just that little bit of amine outgassing got my fingers itching. It's awful on lungs too. They used to put amines into all kinds of things, including industrial enamels. Them was the bad old days. But at least you didn't have to repaint your machinery very often. One of the guys who worked down the road at the epoxy plant can't even touch a backed enamel desk thirty years old without breaking out in hives! How's that for sensitivity?!

 

[polyglot]

Is the time/temperature relation pretty much a straight line? That is, can I just graph out 2:00/20C to 1:00/40C and derive a time for whatever I have for ambient?

Heck, no graph needed if it's linear. That's one minute for 20 degrees C variation so if my solutions are, say, 24C (not unusual in summer, sometimes a bit more) that would be two minutes less 12 seconds or 1:48, call it 1:50?

I believe that print development (including colour) is approximately to completion unlike film, therefore the results are pretty insensitive to time as long as the time is long enough.

I personally use about 1:00 to 1:15 at 35C for RA4 (in Jobo) and any variation in results between those times is smaller than my ability to perform colour and density adjustments. I think the Kodak instructions say 0:45 at 35C but don't really recall.

 

[markd514]

Hey thanks PE. I trust your input 100 percent. You put your time in and def know what you are doing. Maybe we can meet sometime. I am in Alentown PA. I pass through Rochester on my fishing trip to Canada! Keep your info coming my way.. I need it!

 

[DREW WILEY]

I standardize on 2 min at 83F, which includes a brief fill and drain time for the drum. Anything shorter than this, then those fill and drain times become more difficult to factor reliably; anything longer and there is more risk of the temp inside the drum drifting, since I don't want to use any more chem than I need to per print. Since this is all for personal use I just use the chem one-shot. RA4 is pretty affordable to begin with, and trying to replenish it would be counterproductive in my case.

 

[Brent Waterworth]

*Bump*
I wanted to get some insight for preserving chemicals.
Right now, Kodak RA4 chem seems to be really hard to get my hands on but I did find a spot in LA that has large volume quantities of the Developer Replenisher (25gal.) & Blix Part A & Blix Part B (both 100L).

What’s the best way to stretch the shelf life for this?
Obviously keeping it in concentrate form & only mixing per session as needed. (I’ll be doing drum processing as one shot)

Do I need to buy specific storage containers/bottles/etc. to keep the concentrate as fresh as possible? I understand people using soda bottles with the air squeezed out - does this apply for the chemicals as soon as I open them & begin my first session?

Any help/advice is greatly appreciated.

Thanks
-b

 

[DREW WILEY]

The smaller Part B Developer component doesn't last very well at all once opened. A few months, yes, but not as long as the other Dev and Blix concentrates. If it's gone brown and oxidized, too late.

MY method, for sake of optimal consistency: I mix fresh, only enough for a single day's work session at most. I never replenish anything, always one shot usage in drums. (If you have an automated processor intended for monitored replenishment, that's a different story.) When in doubt about the storage life of concentrates, I buy fresh chemistry to have on hand in case the older stock proves unreliable.

Any serious storage of mixed chemicals of any kind - amber glass bottles, period. Thin recycled poly or (egads) non-poly camera store style darkroom jugs are permeable to oxygen and quite inferior. Any serious Scientific or lab supply house like LSS will offer a significant range of storage options along with true specifications abut chemical compatibility etc. But if you don't mind the risk of breakage, true glass bottles with matching caps if the best option, especially on a limited budget. I don't know about recycled Soda containers; but since carbonation is basically dilute carbonic acid, there's some merit to that.

 

[Brent Waterworth]

The smaller Part B Developer component doesn't last very well at all once opened. If it's gone brown and oxidized, too late. MY method, for sake of optimal consistency: I mix fresh, only enough for a single day's work session at most. I never replenish anything, always one shot usage in drums. (If you have an automated processor intended for monitored replenishment, that's a different story.) When in doubt about the storage life of concentrates, I buy fresh chemistry to have on hand in case the older stock proves unreliable. Any serious storage of mixed chemicals of any kind - amber glass bottles, period. Thin recycled poly or (egads) non-poly camera store style darkroom jugs are permeable to oxygen and quite inferior.

Nice thanks for the quick reply Drew.
Understanding that concentrate chem lasts longer & only mixing per session, what’s the best practice to preserve the life of the chem (concentrate)?

Is the original packaging suffice? Or should i plan to put the chemical concentrates into some other type of storage mechanism?

Thanks
-b