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John Layton
10-Dec-2015, 12:19
I have an idea for processing large prints (30x40 and 40x60inch) that I’d like to run by others on this forum.

In a nutshell, the print would remain taped to a larger sheet of plexiglass, for the entirety of the exposure/development/washing/drying cycle.

I’d use a thin, strong, waterproof tape, and with this secure, around its entire perimeter, a blank sheet of photographic paper to a larger sheet of plexiglass, then place this in a large (home made) easel for the exposure (home made horizontal enlarger).

After exposure, the entire plexiglass/paper assembly would be removed from the easel, then propped up over a thin trough (in the darkroom sink), which is slightly tilted to empty into an open (one gallon?) container, which for the first step is filled with water for a pre-soak. The plexiglass/paper, thus upended with its bottom in the tilted trough, would itself be tilted slightly backwards - so that the pre-soak water (and following solutions) could be cascaded smoothly over the print, and find its way back into the gallon container - where it could be either pumped back up to the top of the print (small recirculating pump) or simply dipped and poured over the print using a smaller (16 oz?) container… repeatedly for the length of a given step.

After the pre-soak, a fresh open container of developer would replace the container of water at the low end of the trough, at which time a continuous pouring of developer so that it cascades over the print and back into the trough/container would commence and continue for the appropriate interval. Other solutions would follow in a similar fashion. Thus only one trough would be necessary for everything but the final wash.

After the final fix, the entire plexiglass/print assembly would then be slid into an oversized tray of wash water - and this water would be changed at a sufficient number of intervals to allow for a thorough wash. This large tray of water would also act to offer water savings, as the flow of wash water does not need to be continuous.

After a complete washing, the print, still taped to the plexiglass, would be carefully squeegeed, after which the plexiglass/print assembly would be either propped up or left flat until the print itself is thoroughly dry, after which the print could, finally, be carefully detached. (Alternately, the washed print could be subject to further toning and washing as deemed necessary/desirable…prior to drying).

The advantages I see of the above method are several. For one, it would require a relatively small amount of sink space, as well as a reasonably small amount of chemistry. Oxidation rates would likely be bit higher than if I’d simply used open trays, multiple troughs, or a large tube - but not enough, in my opinion, to negatively affect the thorough processing of a given print. Furthermore, the risk of folding or otherwise creasing of the print would be minimized…possibly to the point of its no longer being an issue - which would be…amazing! I am certain that all here who process large prints (larger than, say, 16x20), are well aware of the dangers and frustrations of creasing and folding, and devising a way to mitigate this, while also solving issues of space and amounts of chemistry, would, I think, offer a compelling case for the use of this method.

The most critical aspect (and my most pressing question) of the above process, assuming fresh chemistry could be “cascaded” over the paper in a manner which ensures evenness, would, I think, relate to the rate of absorption of liquids into the paper itself. In other words, with the paper having been taped to the plexiglass substrate for the entirety of the process - from initial exposure, to processing/washing, to the end of the drying cycle, could I assume that I could adequately apply each solution and then neutralize its presence with each following step….so that each step could be truly effective, and so I could ensure that the resulting finished print would indeed be archival?

My apologies for the length of this post…and any comments would be most welcome. Thanks!

Greg Davis
10-Dec-2015, 12:36
I have heard of similar setups such as this. They used a large sponge to continuously dip and coat the paper for each step. I don't know how even the results are as I have never seen prints processed that way (knowingly anyway). I would suggest you try a small print and see if it works. Since large paper swells when it is wet you may try some kind of spring clip at the top only rather than tape on all sides to give it room to expand.

IanG
10-Dec-2015, 12:43
I've done that a great many times, I either sprayed the chemicals (when I had a very large darkroom with extractor fans or used sponges, use slightly more dilute developer so it slows development, results are very even as long as you're methodical, I never had one that wasn't.

Ian

Michael Wesik
11-Dec-2015, 09:24
I might be concerned about adequate washing. I process my prints in a very similar manner as you describe, pouring my chemicals over the print where they're returned to me through a system of ABS pipe and gutters. In my method, I have a large tray that sits on a platform that can be either laid flat or tilted up on a slight angle. Holes are drilled at the bottom of one end of the tray to allow the chemistry to drain and to plug up for washing, hypoclear, bleaching, selenium, etc. Otherwise, I'll pour my developer, stop, fix, sepia and gold. I use a dedicated pipe/gutter for the developer just as a matter of caution. I've never had any contamination issues and I one-shot most of my chemistry for the sake of consistency. With this method I can make a 56" wide print and tone it with sepia, selenium, and gold. When the print is done processing we slide the tray out the back of the platform, set it on an angle, and pick up the print by its corners and walk it to a piece of plexi for squeegeeing after which it's transferred to a tented drying rack with a humidifier inside (not the kind that produces steam). The humidity helps the emulsion and paper base to dry together with minimal rippling. Hope some of this helps!

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John Layton
11-Dec-2015, 10:00
Michael - the main difference in what I'm wanting to try is that my print would be completely sealed around its edges to a larger substrate (plexiglass or something similar) - from the time of exposure, through all of the processing steps, and remain sealed until completely dry. This would allow for a steep angle down which chemistry would cascade, would minimize handling risks (creasing, etc.), plus minimal issues with drying-induced curl.

My main question (and concern) relates to the amount (and rate) of penetration of various liquids into the paper...given that these liquids are being applied only to one (the emulsion) surface. Keeping in mind that I'm using fiber paper...would liquids migrate through the emulsion and paper to the back surface (wetting both the back surface and the substrate) - or would the back surface and substrate stay dry? And, if liquids do migrate through completely, might I still be able to avoid contamination - assuming that successive liquids would migrate through the paper enough to neutralize the previous liquids? Or would such migration indicate that at some point I'd need to release the print so that I could expose the rear surface to liquids also?

Alternately, if the rear of the paper (as well as the substrate) essentially stay dry, would successive liquids at least penetrate enough to neutralize the previous liquids?

Again...I find the potential advantages offered by my idea very compelling - and at least worth setting up for a few trials. I guess what I'm really needing is some data, if such exists, regarding the amounts and rates of penetration of liquids into the emulsion surface of fiber based papers - in cases where such liquids are applied only to the emulsion and not to the base. Then again...I've got a bit of outdated paper lying around, and in the time its taking me to post this - I could be at least using this to run some tests!

IanG
11-Dec-2015, 10:08
Your chemistry works from the emulsion surface, not through the paper and baryta layer, and yes each step will penetrate enough to neutralise the previous, was both sides though. and I'd soak in wash aid as well.

Ian

John Layton
11-Dec-2015, 15:04
Initial tests are not promising. There seem to be two issues - one: its exceedingly difficult to avoid allowing minuscule amounts of fluid to migrate under the paper from the taped edges, which could make avoiding contamination difficult. And two: the paper buckles significantly shortly after being thoroughly wetted. Being confined on all sides by tape, prior to being wetted, would help to explain this.

So...I'll likely construct something similar to what Michael has shared above. Thanks Again!

Greg Davis
11-Dec-2015, 17:49
Like I said, it is going to swell. You need to give a means to do so to keep it flat.

Michael Wesik
12-Dec-2015, 09:14
I presoak my paper for a good 5 to 10 minutes, drain, affix with a weight at the top of the paper and then apply the poured developer. I've also found that fixing times tend to be longer using a pouring method. I use Hypam 1+4 (8L continuous pouring) for 5-6 minutes for Ilford warmtone paper.

Best,

Michael

Duolab123
14-Dec-2015, 18:40
Maybe this us a crazy idea, but here it is. TAPE down your paper, expose . Tape the fiber base print around the entire perimeter. Soak it good in water so the paper base is totally saturated with water. This should help to keep the chemistry on the emulsion side. Get 3 large clean cellulose sponges. Warm 1 qt. each of Developer, stop, and rapid fix to 95 F. Lay the plexiglass on a table and wipe the warm developer like mad, the print will stop darkening when fully developed. Use as little chemical as needed, shouldn't take more than 6 oz. Stop, for 30 seconds, Fix with a sponge for a good minute. Hypo clear, with a sponge spray it off good. Check backs and borders with residual hypo test solution..

If you wanted to use RC this would be even easier. A buddy of mine and I made a bunch of 6 foot pan shots just using a deep tray and see sawing the print back and forth. If you are not overexposing the print you really can't over develop. Watch the emulsion as it gets quite soft at warmer Temps .

I process b+w on a Kodak rapid color processor, PRESOAK IN WATER . Then 45 sec Bromophen 1+3, 15 s stop , 45s Rapid fix, 1 min SE toner in HCA wash 1 min, then dry.

Duolab123
14-Dec-2015, 18:43
I might be concerned about adequate washing. I process my prints in a very similar manner as you describe, pouring my chemicals over the print where they're returned to me through a system of ABS pipe and gutters. In my method, I have a large tray that sits on a platform that can be either laid flat or tilted up on a slight angle. Holes are drilled at the bottom of one end of the tray to allow the chemistry to drain and to plug up for washing, hypoclear, bleaching, selenium, etc. Otherwise, I'll pour my developer, stop, fix, sepia and gold. I use a dedicated pipe/gutter for the developer just as a matter of caution. I've never had any contamination issues and I one-shot most of my chemistry for the sake of consistency. With this method I can make a 56" wide print and tone it with sepia, selenium, and gold. When the print is done processing we slide the tray out the back of the platform, set it on an angle, and pick up the print by its corners and walk it to a piece of plexi for squeegeeing after which it's transferred to a tented drying rack with a humidifier inside (not the kind that produces steam). The humidity helps the emulsion and paper base to dry together with minimal rippling. Hope some of this helps!

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Very cool. Nuts! But cool!!!!!