Paper Chemicals for Mural Printing?

[John Layton]

Thanks Randy. Do note that the backdraft vents are somewhat less effective due to the tray's high position...and I'm thinking I'll add a "Y" connector higher up so I can direct the vent flow from above this tray when I'm using it.

Also...having one tray does slow things down a bit. I could add a second tray as a holding tank if I needed to...but this would mean stacking and shuffling 30x40's and I really don't want to risk creases and tears by over-handling the prints. As is...I can set up to do a print early - using the tubs directly for processing test strips, then do a complete run (including washing/squeegeeing/hanging, and selenium toning if I want to) for one large print - and then either do a second copy of the same print if I need to, or set up with a completely new image...and get this second one printed and hung, for a grand total of two prints by days end.

I guess I could do things more quickly...and to be honest the longest phase of my procedure, especially for large prints like this - is making and evaluating test strips. With 16x20's, and even 20x30's, I can more easily afford the materials I need to make several copies of a given image if I need to...but with 30x40's, I really like to get what I consider to be a "final" (and saleable) image either on the first or second try.

Part of what makes doing one final print effective is knowing that I can go back later and make a print which is more or less identical to one I'd made earlier...due to a combination of the Moersch 4812 developer (which is extremely consistent until it quickly dies), plus the consistency of my Heiland LED VC head (which required a painful parting with a really nice SWC to purchase), plus trying to keep good notes!

Another thing that I should mention is that the chemical tubs have covers (not shown in photos)...and because of this and as each chemical is poured into the tray and then back into its tank after each step - this means that nothing is laying exposed to oxidation for excessive periods of time.

[Tin Can]

John all advice noted and much appreciated. I have been doing mostly 16X20 and have trays, paper stock to 20X24.

I am plotting a winter's end project to 30X40 and/or 9X34 pano so exploring possibilities. It's another level.

Paper costs more the bigger it gets and I am glad it is still available. Ilford

Thank you again!

[bob carnie]

My approach to printing 30x40's is to use a single, elevated (on 2x4 "stretchers") tray (34x48") which I built from 3/4" birch plywood and coated with marine epoxy. This tray features a tapered right end, with a gasketed flap in the middle of this...which when closed ensures that the tray holds liquid, and when opened allows chemistry to be dumped.

Procedure is to have chemicals in tubs to left of this tray, dump into tray, move empty tub under dump-flap on right side, agitate by tray-rocking, open flap and place 2x4 under left edge of tray to elevate to facilitate dumping, at the end of dump cycle gently squeegee print to save maximum chemistry and minimize carryover of chemistry to next step, remove 2x4, reseal flap, pour in next chemical. Took awhile to get up to speed with this...but it works great.

What I found in "dialing in" the above process is that a pre-soak did not work for me...as it interfered with later absorption of developer which caused some visible unevenness. I'm using Ilford Classic FB (available as 30x40 sheets) and mileage may vary on this pre-soak issue with other papers. At any rate...I find that two gallons of chemistry works fine...and at the start of a run I dump a little less than half of the developer into the tray prior to adding the print, then quickly pour the remaining developer over the print before starting to rock the tray. As for developer dilution...I did find that if I used an "extreme" dilution I had trouble with getting maximum blacks, so I dialed this back a bit and now find that my Moersch 4812, when diluted to 1:24, works great with a four minute developing time (3.25 active rocking plus .75 dumping/squeegeeing).

I also use my single tray for the entire process...including washing/squeegeeing (glass smooth epoxied surface facilitates squeegeeing). This means that the print does not get moved about until it is ready to hang - which minimizes having the print become creased.

Right now I'm printing some 30x40's for an upcoming show using this tray...and down the road I'll likely build a larger tray of the same design to do 40x60's. Will still fit over my sink... although I might need to up the amounts of chemistry for this. Here are photos:
Attachment 180960Attachment 180961

John I am using the exact same tubs, they are about 40 inches in length , very good way to process using the scrolling method.

I also have larger trays which I use as well, both methods are completely satisfying to work with.

[LFLarry]

Based on my first hand experience, here are a few hard lessons that I earned when printing big in trays.

Big defined as 30x40 and 40x50 prints which are actually 32x42 (printed on 42" roll paper) and 56x46 (printed on 56" roll paper).

For 30x40 I found that I needed a minimum of 3 gallons of developer and 5 gallons for 40x50. Anything less, I would get the nasty developer flow marks, etc. and every piece of paper lost was $20 to $27 a pop...

I tried pre-soaking the paper in distilled water before going into the developer and that was a nightmare. The paper soaks up the distilled water and then when you put it into the developer tray, it doesn't ever fully developer properly. If I recall correctly, I think I even let it develop for 20 minutes once to see if that helped and it was a miserable failure. If someone has ever even successful at pre-wetting big prints before development, I would love to hear how that worked.

Of all the methods that I have tried for development (face down for 1 min, two people submerging quickly, large nap roller, etc.), I found that by rolling the paper up after exposure and then pick one side of the tray and unroll towards the other and then quickly submerge the paper into the developer and move developer over the paper with your gloved hands being sure to have it fully covered in about 10 seconds or so. With that method, I have perfect prints every time.

It is a lot of fun to see your prints come to life at this size.

Good luck and keep us posted!

+1 for tray development.
5 litres of developer in 2 buckets, splash and move with hands (gloves) or large brushes/wipes/sponges. works better with a helper.
bob carnie is right, flow marks are the enemy. prewetting the paper helps a bit (might decrease contrast though). diluting developer and cooling helps even more (increased developing time). practice by moving up in size before doing really big ones.
put on some groovy music.
enjoy.

[LFLarry]

John, that is a genius design and technique !!!!

Can you share exactly what epoxy you used? I need to try this and reclaim some space in my darkroom.

I am printing 40x50 on 56" roll paper (46x56 with border) so my trays are HUGE... I found that I used 3 gal for my 30x40 and 5 gal for my 40x50 prints or a factor of about 1.6 going from 30x40 to 40x50 in case that helps you calculate chemical usage in the future.

I was always worried about the epoxy, but now that I know you are doing it successfully, that is all I need to know.

Larry

My approach to printing 30x40's is to use a single, elevated (on 2x4 "stretchers") tray (34x48") which I built from 3/4" birch plywood and coated with marine epoxy. This tray features a tapered right end, with a gasketed flap in the middle of this...which when closed ensures that the tray holds liquid, and when opened allows chemistry to be dumped.

Procedure is to have chemicals in tubs to left of this tray, dump into tray, move empty tub under dump-flap on right side, agitate by tray-rocking, open flap and place 2x4 under left edge of tray to elevate to facilitate dumping, at the end of dump cycle gently squeegee print to save maximum chemistry and minimize carryover of chemistry to next step, remove 2x4, reseal flap, pour in next chemical. Took awhile to get up to speed with this...but it works great.

What I found in "dialing in" the above process is that a pre-soak did not work for me...as it interfered with later absorption of developer which caused some visible unevenness. I'm using Ilford Classic FB (available as 30x40 sheets) and mileage may vary on this pre-soak issue with other papers. At any rate...I find that two gallons of chemistry works fine...and at the start of a run I dump a little less than half of the developer into the tray prior to adding the print, then quickly pour the remaining developer over the print before starting to rock the tray. As for developer dilution...I did find that if I used an "extreme" dilution I had trouble with getting maximum blacks, so I dialed this back a bit and now find that my Moersch 4812, when diluted to 1:24, works great with a four minute developing time (3.25 active rocking plus .75 dumping/squeegeeing).

I also use my single tray for the entire process...including washing/squeegeeing (glass smooth epoxied surface facilitates squeegeeing). This means that the print does not get moved about until it is ready to hang - which minimizes having the print become creased.

Right now I'm printing some 30x40's for an upcoming show using this tray...and down the road I'll likely build a larger tray of the same design to do 40x60's. Will still fit over my sink... although I might need to up the amounts of chemistry for this. Here are photos:
Attachment 180960Attachment 180961

[bob carnie]

Here are the trays I use when I am doing flat prints, when I am doing large rolls 30 inch x 10 ft I use the troughs John uses

1. I use lots of chemicals to avoid flow marks
2. Never pre soak

My trays are 34 x 44 and 48 x 50 inches that are made from grey plastic which is welded and super strong.

[John Layton]

Larry - I used marine epoxy from a company called Rakka. Much lower price than the equivalent from West System, with low VOC and generous setting time...qualities that weren't as important with the tray I've outlined above - but more for the large (3ft x 16ft) sink, partially visible in the photos, which I'd built and installed as my darkroom was coming together about five years ago. This being my twelfth darkroom in just over fifty years...I really wanted to get this one right!

The sink basin I built in two sections out in my garage...and moved these down to the darkroom to affix (with short screws and mending plates) onto the 2x4 framework which I'd already built in place, then I joined the two basin halves (glued and screwed), and then completed all shelving, etc., then installed the vent system prior to sealing all with the Rakka epoxy - thus epoxy fumes were mitigated.

On a side note...I had a bit of Rakka epoxy left over from the sink project - and used most of this to seal a set of five 24x34 inch trays, which I now use to print 20x30's. When I grew interested in printing larger...I knew - even with the possibility of squeezing in four 34x44(ish) trays into my sink, and using a single fix - I really did not want to take up that space in the sink...nor did I want to deal with the logistics of pouring, dumping, washing, and storage of such large trays...nor did I want to compromise the efficacy of chemicals through long exposure to air...nor did I want to "waste" lots of chemistry through what would be the large carryover from tray to tray. At any rate, I had just enough Rakka left over to seal this large tray.

The single tray solves all of the above mentioned issues. Furthermore, the reason that it can work with a relatively small amount of chemistry (and this applies especially to the developer) is that I am starting this (developing) cycle by pouring a small quantity into the tray prior to placing in the exposed paper...then quickly pouring the remaining developer over as much of the paper as possible to ensure quick, even coverage. It is then that I begin rocking the tray, which is very effective with this tray, as the edges are 5" high so I can really "rock it" with no spillage whatsoever. Also, as mentioned, chemical carryover is minimized by gently squeegeeing the print near the end of each dump cycle (with tray tilted upwards)...with the print remaining in the same, image side up orientation, as the pressure from the squeegee, while gentle enough to do no harm to the emulsion...is still firm enough to force out most of the liquid which would otherwise remain trapped under the print. Indeed, solution volumes on the "dump" side pretty much equal those on the "fill" side (although this data is meaningless for all but the developer, as all following chemicals receive some degree, however small, of carryover).

In fact, throughout the entire development cycle, the print is never flipped over, although I do gently lift one or two edges at the beginning of a tray rocking cycle to facilitate initial chemical circulation under a the print - and once rocking commences, chemistry flows and moves freely on both sides of the print. The only time the print is flipped comes just before dumping the final wash water...when I gently flip the print over, dump the final wash, and squeegee the back (glass-smooth epoxy finish keeps print free of dents/scratches) prior to flipping once more to squeegee the front prior to lifting out - and for this (lifting) I attach the hangers first...so that I can lift evenly and hang on the drying line with little to no risk of bending and/or creasing (and boy, do I ever hate creases in my prints!).

Jeeesh - am I getting long winded in my old age! But there is something else I should mention. This tray would be very difficult to use effectively (at least with my current 2 gallon volumes) with paper cut from a roll...unless one were to first "reverse curl" the paper prior to processing. The paper I had on hand during the testing phase of this tray came from the end of my last (42" wide) roll of Ilford Classic - and boy...was this an adventure! I first tried plopping the exposed/curled sheet into straight developer and lost too much time trying to "de-curl" the paper during this cycle, getting horrible results. Then I tried a five minute water presoak (more than enough time to flatten the paper), and while results were somewhat improved, I still got lots of unevenness, particularly noticeable in broad, non-textured areas of even tonalities. I then tried a combo of pre-soak and highly diluted developer - and, while results were a bit better, the prints still exhibited unevenness. My guess was the the pre-soak itself was interfering with the later uptake of the developer.

About the only way I could see using this tray with paper cut from rolls would be to invent some sort of "hold down" system - so that the paper's uncurled edges could be held slightly above the bottom of the tray - for at least long enough to allow the paper to relax a bit as solutions begin to penetrate. Another strategy (which I believe that someone else has already mentioned) would involve actually re-rolling the exposed paper onto a dowel affixed slightly above the rear of the tray...and then scrolling downwards from this into the tray. This might actually work quite well, and could present what might be the best of both worlds between using a "scroll and trough" system and open trays. The further advantage of this, in that it facilitates the use of rolled paper, is that such rolls are available in a larger variety than are pre-cut papers, and the cost per square inch of rolled paper is generally quite a bit less than that of sheets.

At any rate...for all of the above, I do hope I've given the starter of this thread at least some good info!

Bob...I had to refresh this page so did not see your above post - do you build your large plastic trays or buy them already built?

[bob carnie]

I had a plastic welder dude make them for me , expensive but perfect for the job, they take a beating and have handles that really help when rocking the print.

[Tin Can]

John your addendum is well received. Very though with specifics.

I will try Raka and had already planned on flat cut paper.

I am not a fan of rolling my negs in tubes. I don’t. Paper may be worse.

Please keep writing as you share very valuable experience.

Ps I am also building a small wood boat. Raka!

[Tim Layton]

Hey, what a great thread!!

I thought I would chime in a little bit and share a few things based on my experience in case it can help anyone.

I started printing big back in 2010 and built custom trays for my 40x50 prints. I over built them and they were HUGE and very heavy.

When I moved and built my new darkroom in 2015, I started rethinking everything and I have been exploring a variety of methods for developing big prints over the last couple of years.

My most frequently printed size is 42x62, but I routinely print 32x42 and 24x72, all from roll paper.

I also recently moved form printing via 4x5 negatives to 8x10 via my Beseler 8x10 system on the 45V-XL chassis.

Over the last several months, I have been testing tube development which I got the idea from Ken Osborne. Ken has a really sweet setup for his 30x40 prints that is basically like a huge motor driven Jobo type of deal.

I tested it and didn't really care for it too much. I missed having my hands on the prints and being able to watch things as the process advanced.

So, I went back to the drawing board and designed and built some new trays and like John, I ended up doing a single tray for my dev/stop/fix1/fix2 and then a separate tray for selenium toning and archival wash via a Kodak tray syphon. My single tray design is a lot like John's, but instead of using Epoxy, I found some thick sheets of Plastic PVC that I was able to cut with a skill saw and glue on to 1/2" plywood along with a large exit gate like John's. I built my water holding tray first and then did the more complex single tray. Here is a video of my wash tray on YouTube at https://youtu.be/hUrp_8eifJg

I sealed the seams with 100% silicon and they have never leaked so far.

I found that I liked to have a regular tray (not the quick drain design) as my water holding bath and another tray dedicated to my selenium toning. So, I was able to go from 6 HUGE trays down to 3 which was a big space savings for me.

I use about 2.5 gallons of developer for my 32x42 and 4 gallons for my 42x62 prints. I trim an inch off my prints after they are flattened.

My development technique is to roll the paper after exposure and then place the rolled paper on the right side of the tray and then release it to the left and quickly submerge it below the developer line and work it with my gloved hands to ensure I have total coverage in the first 15 to 20 seconds or developer streaks will occur and ruin the print. I will also confirm that pre-soaking the prints in water does not work. The bigger the print, the bigger the risk and hassle factor, but it is all worth it when you see those big prints.


Tim