Big Big Prints - 7.5'x6' - What does it take?

[holmburgers]

Fascinating accounts from all.

Mick, your view into the operation, and cooperation is most telling. I can't imagine the expense of messing up something that big, and of course getting an artistic and perfectly rendered print; it's very impressive.

A good read from many, thanks.

On a side note; a professor at KU and I were talking about big RA-4 prints, though more like in the 36-48" range lets say. He emphasized that none of that stuff was done in trays, "no way" he said. It was all roller processor stuff, and he made a comment that this had to do with the surge in large color prints in the 80's, particularly at universities where students had the ability to mess around with those sizes now.

[DREW WILEY]

I'm going thru fits deciding whether or not to install a 50" Kreonite or just stick with the 30x40 drum
processor I already use. I could make a much bigger drum system, but I think anything bigger than
30X40 and the chemical cost efficiency would signifiant decrease, because larger and larger relative
volumes would be need to keep the temp tolerances tight. Fill and drain time also become bigger
issues. Really monstrous prints have zero market in this part of the world, and if Scarface did build
a really ostentatious Miami mansion around there parts, his taste probably wouldn't correspond to
anything I print anyway.

[Bob Carnie]

Drew , do yourself a favour, keep the drums, it is a constant issue for us to keep paper going through our 30 inch RA4 machine.
To keep it in control we basically have to run exposed paper each day,,,, demand or not otherwise the process goes bad.
Keeping a good line going with RA4 is not as easy as one would think and the key ingredient is exposed paper.

I'm going thru fits deciding whether or not to install a 50" Kreonite or just stick with the 30x40 drum
processor I already use. I could make a much bigger drum system, but I think anything bigger than
30X40 and the chemical cost efficiency would signifiant decrease, because larger and larger relative
volumes would be need to keep the temp tolerances tight. Fill and drain time also become bigger
issues. Really monstrous prints have zero market in this part of the world, and if Scarface did build
a really ostentatious Miami mansion around there parts, his taste probably wouldn't correspond to
anything I print anyway.

[DREW WILEY]

Yes, thanks Bob. My logic is that I'd just run the machine seasonally a few months and do all my RA printing
in sequence, then have to clean it out for the rest of the year. The drum would be available for casual work.
But drums are pretty slow for the whole sequence of test strips, print, reprint etc. And by simply disconnecting
the dryer I don't need any new wiring. Some plumbing and space headaches, yes.

[Danielle]

Danielle:

Note the instructions for tray development in Kodak publication J-39: http://www.kodak.com/global/en/profe...bs/j39/j39.pdf

If you read through a variety of Kodak technical publications, you will realize that there will be specific and detailed warnings if certain chemistries or processes involve unusual safety concerns. J-39 includes no such warnings.

It is not that care isn't required, but rather that the usual sort of care is sufficient.

Thanks, I had a squiz at a it. Interesting. Ok, so obviously its still chemicals and care is required a decent dose of it, but it can be done reasonably safely. Cool. - I've actually never done colour since doing it through a machine. That was really cool, put it in the machine on one end in complete darkness and grab it at the other end completely dry. Neutralise the colour, dodge/burn and spit it out again. I still think thats the best way but I do believe those machines cost a small fortune not to mention take up considerable space.

[DREW WILEY]

Yes those machines did cost a fortune. I won't say what I can get one for.
But Bob already pointed out how they have to be keep in pretty much
continuous operation to be reliable. There also tends to be municipal
effluent regulations regarding true industrial processors, and they need a
LOT of wattage dry to dry. But since my office is just a block away from a
major industrial and scientific pipe supplier, I was just wondering whether
I should just go ahead and make a drum processor from hell with virtually
no maintenance issues whatsoever. They stock plastic pipe up to 24 inches in diameter and can get it up to six feet in diameter, just about anything. But I just wonder if I want to tackle yet another shop project,
even though I'm perfectly comfortable with plastic fabrication.

[Bob Carnie]

Ok that makes sense, if you have space, John Callow does this with RA4 himself.

Yes, thanks Bob. My logic is that I'd just run the machine seasonally a few months and do all my RA printing
in sequence, then have to clean it out for the rest of the year. The drum would be available for casual work.
But drums are pretty slow for the whole sequence of test strips, print, reprint etc. And by simply disconnecting
the dryer I don't need any new wiring. Some plumbing and space headaches, yes.

[langedp]

Yes, thanks Bob. My logic is that I'd just run the machine seasonally a few months and do all my RA printing
in sequence, then have to clean it out for the rest of the year. The drum would be available for casual work.
But drums are pretty slow for the whole sequence of test strips, print, reprint etc. And by simply disconnecting
the dryer I don't need any new wiring. Some plumbing and space headaches, yes.

That's what I do Drew. I have a 30" Kreonite RA-4 processor in my darkroom that I only fire up occasionally, primarily when I want to do 30"x40" prints. I even drain the tanks back into some large containers after a session and rinse the machine down. I'll then fire it back up a day or so later. Once I've consumed my replenisher I pretty much shut it down, rinse it out well and then it sits for months until the need for 30"x40" comes up again. I use my Jobo system for everything smaller. Considering I got the Kreonite for free, it has been a pretty good set up.