RA4 in a cibachrome tank
I might be able to get hold of a Cibachrome tank (11x14" size I think) -- which is the biggest I am likely to need anyway -- I've been doing RA4 at home successfully for a few months now.
I've been using trays though.
I was wondering -- there's no reason not to use a Cibachrome tank is there? Just roll the paper up and pour in enough chemical (dev, stop and blix) at the appropriate times and I can then do the chemical bit in daylight/normal light.
Are these tanks 'light proof' like daylight film dev tanks? Or would i need to switch off lights between the stages to change the chemicals?
Originally Posted by lilserenity
I currently use the Cibachrome tanks for black and white RC, but they are/were designed for daylight processing of colour materials that require that the paper be in absolute darkness, so they should be well suited for RA4 materials.
You should of course check that there are no cracks and no other signs of physical damage that might cause light to leak.
I'm not sure whether it is a good idea to do smaller prints in the larger tanks - I generally use my 8x10 tanks for 8x10 prints. An 8x10 in a 11x14 tank might not stay in place.
You will need to fine tune the volume of chemistry you use - for black and white chemistry I find that about 100ml gives me even results, as long as there is enough capacity in the chemical itself.
I have done ra-4 in ciba tanks in the past. They need a plastic disc in the bottom to complete the light trap. Make sure that your rig has one. Pre warm the tube with hot water before the developer goes in; the develoiper volume is so small it is not enough to keep the activity up. Fortunately RA4 is mostly a develop to completion process.
I seem to recall that the ciba internal cup has a capacity of about 300mL , so that may be a bit less than the volume that Kodak etc recommends as a pre wet when working in tubes.
Any number of 70's colur printing books will discuss the details of printing colur with daylight tubes.
Have a ready supply of drying means. I used worn out tea towels that were too ravelled looking to dare hang in the kitchen and dry dished with any more. You must rinse the tube by washing at least a bit by rinsing the print in the tube. Get all of the blix out so it does not get carried over into the next run of developer, or wierdness will ensue on that print.
I used to semi-repensih with the dev and blix. The prints onlyy needed about 50mL per print, but I found that more solution would help covering the print evenly. So I would just add 50Ml of fresh developer solution to a cup that also contained the used dev. Same proceedure for the blix. Pour off the used quantity to leave only 100mL used to 50ml fresh. The first print of a session used 100mL fresh to get the system started.
Good luck with your efforts. I now have a roller processor for RA-4, but have kept the stable of tubes I once used for the day when the processor breaks and parts can no longer be sourced.
Oh - as to print sizes - the cibas do not have size dividers. likel the unidrums and sima drums I have. Other drums have dividers that can be adjusted, eg two 8x10's in a tube that normally only prints 11x14 with no divider ridges. You need something that keeps the paper close to the wall of the tube.
Look if you can find a store that sells used photo gear including darkroom gear. They are usually awash in these tubes in the used section.