RA-4 Temp. Control Tips?

[jakelovesphoto]

Hello all! I just recently started processing RA-4, using trays. I tried room temperature but it was dismal. My expired chemicals (they were free) need to stay right at that 35*C mark. I've tried floating the tray in warm water but the temperature falls and the color shifts. Any RA-4 temp control tips out there?

 

[pentaxuser]

Can you expand on "dismal"It is just that several others seem to have success with trays at room temp and I wonder what it is that they do that might help you.

pentaxuser

 

[MartinP]

Success may depend on the brand of the chemicals, as well as their age. The Kodak RA4 docs give example temperatures down to 27C with the advice that the filtration may change -- if the OP is seeing changes with temperature then this is actually expected. The problem then would be keeping the temperature consistent, rather than having no results at all, and the optimal tray results are when the room+water bath+chemicals are all at the same temperature.

In Kodak publication J-39, note that the developer time for trays is based on one minute at 33,3C (92F), with variations and compensation listed for higher or lower temperatures including two minutes at 27C. The capacity is sixteen 8x10" prints per litre. In the case of the OP, most likely the chemicals are not Kodak and/or are completely clapped out. Also note that a stop-bath is a very good idea and decent ventilation is pretty much essential.

EDIT: I just did a quick check in the usual online places and aquarium thermostatic heaters are very cheap. The range goes between about 25C and 32C so should be ideal for keeping a water bath at a usable temperature. I suppose a big seed tray from a garden centre would be good, keep the heater near the developer-tray and stir the water-bath occasionally?

 

[Wayne]

Hello all! I just recently started processing RA-4, using trays. I tried room temperature but it was dismal. My expired chemicals (they were free) need to stay right at that 35*C mark. I've tried floating the tray in warm water but the temperature falls and the color shifts. Any RA-4 temp control tips out there?

Some ideas here. I bought a used lab tempering bath for maintaining the chemical temps before they go in the drum. Some people have modified cheap aquarium heaters to work above 100 degrees F by removing the dial stop, but I tried it on my good heater and it didn't work.

(there was a url link here which no longer exists)

 

[jakelovesphoto]

Can you expand on "dismal"

pentaxuser

At room temp (55 in my basement darkroom) no matter how long I develop there's is a very strong red cast. And if I try to filter it out I end up desaturated. This doesn't happen with floating the tray in warm water, but that does cool. Shifting my development with each print.

 

[jakelovesphoto]

Success may depend on the brand of the chemicals, as well as their age. The Kodak RA4 docs give example temperatures down to 27C with the advice that the filtration may change -- if the OP is seeing changes with temperature then this is actually expected. The problem then would be keeping the temperature consistent, rather than having no results at all, and the optimal tray results are when the room+water bath+chemicals are all at the same temperature.

In Kodak publication J-39, note that the developer time for trays is based on one minute at 33,3C (92F), with variations and compensation listed for higher or lower temperatures including two minutes at 27C. The capacity is sixteen 8x10" prints per litre. In the case of the OP, most likely the chemicals are not Kodak and/or are completely clapped out. Also note that a stop-bath is a very good idea and decent ventilation is pretty much essential.

So it should be noted that my chemicals are ten years out of date. (I know, I know, it's practically a crime) but I'm still learning and they were free. I'll order new bottles once I get a but better at this. When I can get the temp up to 95 I get surprisingly reasonable results. I do use a stop bath, that helped a lot. I just need a way to keep consistent temperature in the 95* range. At 55 no amount of development can filter out the red/magenta cast.

 

[MartinP]

Fifty-five degrees (Fahrenheit) is what you would call "very optimistic"!! If you use a water-bath at that room temperature, for example with a submersible heater, then cut a cover from bubble-wrap with holes for the trays you are using and perhaps cover the trays except when you are actually in the dark using them. That might help with some consistency over the few minutes processing time.

I am happy to say that I have a heated Nova slot-processor, which makes this sort of thing so much simpler...

 

[jakelovesphoto]

Has anyone tried floating their trays in one of those electric casserole dishes? Those are always at Salvation Army, and could keep the water bath in the 90-100 (32-37ish Celsius) degree range.

 

[Wayne]

A cheap aquarium heater will keep a tray in the 93 degree range, even without modification.

 

[Wayne]

But an aquarium heater won't make your chemicals fresh again.

 

[madgardener]

If you are going to use an aquarium heater for the temperature control, I suggest you get the aquaculture brand from Walmart. All you have to do is just pull the knob off and reposition it at the beginning and continue to turn. It'll take a couple hours of adjusting to get the temp exactly right but it does work quite well and is a very cheap option if you consider your time free. I also recommend a small aquarium pump to circulate the water bath that your chemical trays are sitting in to prevent hot spots.

It won't make the chemicals fresh however, but there are many threads on C-41 chems here.

 

[Wayne]

I also recommend a small aquarium pump to circulate the water bath that your chemical trays are sitting in to prevent hot spots.

I just jiggle the tray frequently.

It won't make the chemicals fresh however, but there are many threads on C-41 chems here.

That's worth repeating.

 

[DREW WILEY]

I'd be more concerned about the health effects of RA4 in open trays, because any suitable air draw across the trays sufficient to get the vapors out of your way obviously leaves the surface of the chem itself susceptible to the air conditioning effect, and hard to maintain temp.
You can make a water jacket with an oversized tray. This is simple enough. Anything really decent for temp control isn't going to be found
at WalMart or some pet store. You'd be better off looking for true darkroom temp valves or whatever, and hoping for a deal on something used. I prefer drums by a long shot, and a simple tempering box with the chem kept in tight temp compliance in bottles.

 

[mklw1954]

I use drums as I think breathing those chemicals should be minimized. Even using drums I have ventilation.

For temperature control, I use an 8 oz. plastic spring water bottle for each of the pre-wash water, developer, blix, and final wash water, using 70ml for 8x10 prints and 140 ml for 11x14 prints. I adjust the temperature of each to 83F/28.3C before adding to the drum using a digital thermometer with a wire probe, calibrated to a color thermometer, and a pot of hot water and cold water. The thin-walled plastic bottles allow rapid temperature adjustment and using a drum allows plenty of time to adjust the temperature before the next addition. I use Kodak Ektacolor chemicals once and discard: 30 seconds pre-wash, 2 minutes developer, 2 minutes blix, 1.5 minutes final wash. I have used this approach successfully at a room temperature as low as 66F/18.9C, i.e., the lower air temperature does not cause the chemical temperature in the drum to cool enough to affect results. It may be effective at even lower room temperatures but this is the lowest I've worked at.

The prints are beautiful.

 

[mnemosyne]

In the beginning I used drums and then trays to develop RA4, a rather complicated setup. Some type of sealed heating pad at low temp setting covered by waterproof material, on top of that a large plastic storage box filled with just enough water to make the developing tray float a bit in it. The storage box was closed with a lid. I used this to develop at 25C, higher temperatures proved difficult to maintain over several hours in my rather cold darkroom. The lids were only opened to put paper in the tray or remove from there (agitation can be done by gently rocking the storage box), which helped minimize vapor from the chemistry. This worked surprisingly well but of course you are restricted to smaller formats and I found it to time consuming and you spend a lot of time in total darkness, so I bought a used tabletop roller transport machine cheaply. I admit, I had to invest a bit to get the machine running correctly, but that was well worth it, as working with it is a dream now. You can turn on the light the moment you have fed the paper into the machine and start preparing your next print. I would consider drum processing only for formats wider than 12" (max format for my RT machine), but the suitable Jobo tanks are quite expensive and difficult to find.

The RT machine I use is a German built Thermaphot ACP302 Vario and I would recommend it to anyone who is serious about RA4 and mostly prints up to 12"x16". It was produced until about 10 years ago and is not difficult to find used here in Europe. It was sold worldwide and with a bit of luck you should be able to find one in the States, too. However, you will have to find someone to service the machine if you cannot do it yourself. The basic elements of the machine (engine, pumps, heating) are very robust and it is likely that they will be good to go. However, the rollers in the racks will have to be replaced, as the rubber is hardening over time (which is a natural process, the average life expectancy of a rubber roller is around 7 years, I was told). The company (coincidentally the company who also built the RCP machines for Durst) is still offering service and parts for the machine and the owner is a very helpful and friendly guy. The machine has a very small footprint, uses very little chemistry (2.4 litres per tank) and is easy to maintain. Rinsing and drying is done outside the machine (in trays), but I do not find this to be a big problem. The "Vario" designation means that temperature and transport time can be adjusted within a wide range, which makes it also suitable for processing b/w RC paper.

 

[jakelovesphoto]

I would love a roller transport machine, but as an unemployed HS student, my budget is very minimal. Your water bottle tip is excellent however!

 

[RPC]

Is there any way you can just heat the room, say with an inexpensive space heater? Then you could just use trays at normal room temperatures. That would be very easy to set up and about the cheapest way on your limited budget.

 

[mnemosyne]

I would love a roller transport machine, but as an unemployed HS student, my budget is very minimal. Your water bottle tip is excellent however!

I will see if I can find a pic of my old setup or "re-enact" it for you later. I was thinking about an immersion heater too, but I discarded the idea as I preferred to have the electricity/heat source strictly separated from the liquids when fumbling around in total darkness. Also, the heating pads are cheap (~15 € each) and simple devices that give heat over a big surface, so all parts of the water jacket are warmed evenly. Additionally, I used a peace of insulating mat below the heating pad to insulate it against the cold surface of the desk.

 

[DREW WILEY]

One way help trays sustain correct temp in a water jacket is simply to cut plexiglas or other plastic lids for the trays, which you lift off just before using them. If the water jacket tends to lose temp, you can simply put a hose into it from the faucet with a slow hot water drip, then let the water jacket overflow a bit. If this causes the developer tray to float, simply glue some kind of feet onto the tray, to elevate it a bit. There are all kinds of low-tech tricks you can do, but RA4 is a bit finicky, because going outside the temp parameters will induce a color shift, making it hard to color balance your project in the enlarger, so back and forth you go, chasing your tail, wasting time and money. But if you try to rely on only room temp to keep the solutions correct, that implies that the outdoor ambient temp is also correct - otherwise, when you turn on the ventilation, there goes that whole idea! And if you don't have ventilation, well then, I'm wasting my time posting, because it will be your lungs that need fixing and not your faucet.

 

[Wayne]

I'd be more concerned about the health effects of RA4 in open trays, because any suitable air draw across the trays sufficient to get the vapors out of your way obviously leaves the surface of the chem itself susceptible to the air conditioning effect, and hard to maintain temp.
You can make a water jacket with an oversized tray. This is simple enough. Anything really decent for temp control isn't going to be found
at WalMart or some pet store. You'd be better off looking for true darkroom temp valves or whatever, and hoping for a deal on something used. I prefer drums by a long shot, and a simple tempering box with the chem kept in tight temp compliance in bottles.

I don't know how it does at higher temperatures, but my aquarium heaters work extremely well for maintaining tray temps at 68 in the winter in my cold darkroom. My temps vary less than 1 degree F, but since I'm not doing color in trays I've never needed to know if it does better than that. But they should work quite well for people doing color work around room temp in trays, though I don't do room temp color either.

 

[madgardener]

I'd be more concerned about the health effects of RA4 in open trays, because any suitable air draw across the trays sufficient to get the vapors out of your way obviously leaves the surface of the chem itself susceptible to the air conditioning effect, and hard to maintain temp.
You can make a water jacket with an oversized tray. This is simple enough. Anything really decent for temp control isn't going to be found
at WalMart or some pet store. You'd be better off looking for true darkroom temp valves or whatever, and hoping for a deal on something used. I prefer drums by a long shot, and a simple tempering box with the chem kept in tight temp compliance in bottles.

While I haven't done RA4, my little cheap heater keeps the temperature at 102F without any problems for C-41. 102F is what's recommended in the Unicolor kit that Freestyle sells. In fact yesterday I turned it up a little more and got the water to E-6 temperatures without any problems and it held there with 3 one liter bottles filled with 68F degree water until they came up to temperature.

Not all of us are dripping with cash and have to do the best we can with what we can afford. If however you would like to donate a complete working darkroom, I would be more than willing to accept.

 

[DREW WILEY]

Believe me, I first learned on a very tight budget too. I also know that, at a certain point, it's counterproductive in terms of paper and chem
expense, not to mention your own time, to not think about doing things a better way. All kinds of excellent lab gear is out there for downright free if you scrounge around a bit. If not, then there are inexpensive ways to jerryrig a better mousetrap. But color balancing RA4 gets problematic once temp gets out of bounds a bit; and working with trays in the first place compromises some of your latitude in that respect. You don't need to be "dripping with cash"; but it might help to learn how to rig up a basic "drip line" to an improved water jacket. But my way of looking at all this is to simply not buy that super cool new lens you don't really need, and spend a little more on the dark side, cause you're only as good as your weakest link when it comes to outputting the final print.

 

[TheFlyingCamera]

Unicolor and/or Beseler drums can be had quite inexpensively, along with the rotary motor bases, if you have a little patience and shop around on Craigslist and/or local classifieds/estate sales/etc, or a little luck on Ebay. Do yourself the favor and invest the needed time to find a cheap set. Then you can get a large plastic tub to immerse your mixed chemicals in, along with the aquarium heater and circulation pump. And do yourself another favor and spend the (not very much) money on fresh chemicals. It's one thing to play with expired chems once you know what you're doing - but trying to teach yourself something from expired chems is a really bad idea because you'll teach yourself to compensate for the bad chemistry without knowing how/why it's going wrong, and you'll waste a lot of money and paper when you do buy fresh stuff trying to un-learn bad habits.

 

[DREW WILEY]

You don't even need a roller base, though that is a nice convenience. You can simply gently roll the drum back and forth along the bottom of
your sink, or manually spin it while floating atop a water jacket, which could be as simple as a ten buck ABS mortar tray from a hardware
store. But it's really the temp inside the drum that counts. RA4 is not extremely nitpicky in this respect - it's fairly easy - but temp control is a LOT more critical than in basic black and white work, because if you're out of bounds time/temp-wise, color will be off too.

 

[jakelovesphoto]

temp control is a LOT more critical than in basic black and white work, because if you're out of bounds time/temp-wise, color will be off too.

This I have noticed. Every time the color balance is getting decent I have to adjust or temperature. Hence my asking here. I think it's clear that drums are the way to go. Maybe (someday) a RT processor.