DIY Large darkroom paper development ideas

[Corran]

So I've been pondering large paper development mechanisms. Up to 50" x 40" but in a PVC tube.

40" width would roll up into a 13" PVC tube. I'm guessing it'll flop inwards from the weight at that size, so my thought is another 12" tube internally, with a bolt and nuts in between the tubes to hold them together on one side, opposite the center of the paper. Obviously something that won't rust, maybe some kind of plastic/teflon will work well, especially weight-wise. I'll also have holes drilled throughout to distribute chemicals freely since it doesn't need to be light-tight, and no end caps or anything:



Then, custom trays from Tap Plastics or similar. Length of a bit longer than 50", 15" wide to fit the tube and bolt on the top, maybe 10" deep so I can roll it in the chemicals? Should slide right in with the open ends and not float, but maybe I need larger trays to easily manipulate the tube. I will probably use more dilute chemicals for a slower development time, for ease of processing.

Total area needed for 3 trays, about 4' x 5', which will fit perfectly on my new 5' wide bench.

Thoughts? Is this a stupid idea? Any ideas for refining this? I just had the thought that after one print, the tube will be wet and difficult to insert paper into maybe. I have some PVC, I'll get it wet and see if paper slides on it. Or is there another, different material that would work better?

[Gary Beasley]

Ive seen where folks will often use a wallpaper trough, and roll the sheet into the solution and unroll and reroll several times until the step is completed then go to the next trough. Not sure how the wash was handled, but bet it was in a similar fashion.
My self, Ive processed oversized prints with a sprayer, could be done using a sheet of plexi to stick it to with a trough under the end to collect the runoff.
Another thought, design the tube to wrap the paper around the outside, stick a rod inside the tube to hang on supports so you can rotate the drum in a tray of chemicals.

[Corran]

Ah yes, I was thinking about the outside of the tube as an option as well. Trouble would be getting the paper to stay put...I'll have to think about that.

[Gary Beasley]

You would have to use clips of some kind. I used a film processor once that worked a lot like that, clipped on the lead edge and wound it around the drum. Processing was pretty easy.

[Drew Wiley]

There is all kinds of good information on the web about making and using big tube systems. Corran is going to have to be polite if he expects me to point anything out to him. But Google on its own is sufficient is one is determined.

[Corran]

Google is overrun with hits for developing film in tubes, being obviously a very common technique. The generic terms involved give me no relevant information for large 40+ inch tube development, except a generic article from Tim Layton with no useful information and a broken link to a YouTube video that's been removed. If you don't want to share resources for the greater good of the forum, that's up to you.

[LabRat]

Gary explained the usual method, but once the roll is inserted in dilute developer, you stick your gloved fingers into the curl at the edges, and run them into the core of the roll to create space for dev to evenly wet entire rolled print surface, and repeat several times...

Strongly suggest practice using RC for awhile to get the hang of it, and is much easier to wash throughly..


Steve K

[Eric Woodbury]

Here's some 'blue sky' ideas.

About 1970, I made a sort of knock-off of a color canoe. Color canoe was a stainless steel tray that was curled, so it didn't use much liquid. I made mine out of cardboard and covered it with fiber glass and resin. It allowed me to develop 16x20s. I also had a couple of trays that were just 2x4 frames that sat on the garage floor that I tucked in with vinyl plastic sheeting. These were fine for making a few prints. Not many. The canoe was pretty good.

Movie film isn't very wide, but sure is long. It is wound onto a reel loosely with a plastic apron between layers. If you can find some sort of apron material, the tube would work well.

There are long and skinny "nesting trays". This would require two people to roll the print back/forth.

There are 4x6 ft plastic trays for growing hydroponic plants. Other sizes.

See if you have a plastic vacuum forming company in town.

Make trays out of plywood and have them sprayed with truck bed liner.

[Corran]

Practicing w/ RC is a good idea. I'll probably need to build one "full-size" tray for washing outside like I used to, in the yard. RC certainly is easier in that way. Goal will definitely be FB prints though. My goal is to not have massive traditional trays/sinks though as I don't really have the room unless I build out a whole other area for print development.

I have a 6x12 image from last winter that I think would look fabulous at 48 x 24, so that is my first goal I think, once I get things built. First step was getting the enlarger setup built so on to the next.

[Gary Beasley]

Let me know if you need help.