Trough Printing

[SeanEsopenko]

I've briefly heard about some people using a trough for printing large works in the darkroom. It's sort of V shaped and they slide/roll the paper through it. I couldn't find much of an explanation in the books I have and I googled for a bit to no avail. Does anybody have a link, recommended book or explanation of how it works and the design of such a trough?

I'd like to print 20x24's and larger in my dark room but the limited space leads me to think that this might be my solution.

[Jon Shiu]

You might also consider a print drum.

Jon

[Filmnut]

Long time ago I used to do mural sized B&W prints on 50" wide paper, and processed them in V shaped troughs that were 55-60" long, and about 10" high and the same wide, or so, with a flat bottom, say about 5".
Worked quite well. We used longish development times, in the 4 min range to get even development, in Dektol, likely 1-2 or 3 dilution, but I'm not really sure about that. The toughest part was to (no pun intended) develop a technique so that you avoided getting kinks in the paper.
The troughs were hand made by us out of PVC plastic sheets, and hot air welded together.
Keith

[SeanEsopenko]

Long time ago I used to do mural sized B&W prints on 50" wide paper, and processed them in V shaped troughs that were 55-60" long, and about 10" high and the same wide, or so, with a flat bottom, say about 5".
Worked quite well. We used longish development times, in the 4 min range to get even development, in Dektol, likely 1-2 or 3 dilution, but I'm not really sure about that. The toughest part was to (no pun intended) develop a technique so that you avoided getting kinks in the paper.
The troughs were hand made by us out of PVC plastic sheets, and hot air welded together.
Keith

As for the actual printing out of the image, did you slowly guide the paper through in one pass, or guide it back and forth a few times keeping it wet? Were they lined up so that as soon as it was out of the developer trough it was in the stop batch trough and finally the fixer trough?

[bob carnie]

Sean

I am trough printing today, I use large plastic ones designed for *under the bed * storage of sock shoes and things from home depot.

I will mix about 35 litres of dev, and the same for the rest of the chems.
Basically you leave a unexposed edge, you angle the whole roll into the chem as a roll and never let the paper come out of its roll during the whole process or you are screwed, and submerge completely and then take one end and start rollining/scrolling it back on itself with the main body of the paper in the chems.
IT MUST BE STATED THAT I AM SCROLLING THE PAPER TOWARDS MY BODY SO MY HANDS ARE STRAIGHT OUT FROM MY SHOULDERS AND SPREAD OUT THE WIDTH OF THE ROLL. very important.
Once you have scrolled through the entire sheet , you gently lift turn and resubmerge as a complete roll and start again. This reverses the action and you should be able to do this within 10 to twenty seconds. Try to keep the roll somewhat tight when rotating and its a breeze.
I do not work from the middle of the roll , or in fact anywhere where image is so as to not **finger dimple** the image, the fingers only touch the outside edges where I have left unexposed paper.


Dev time is extended to three minutes and forty seconds and I always use fresh chems.

This is a very good method of processing large prints, just takes a couple of practice goes , good music to keep the beat and lots of confidence as it does work well.

To date the largest sheet we have scrolled is 30inches by 12ft.
Today I am going to scroll a 40x50 for the first three stages and then put in monster tray for the final steps.
Even though I have a very large sink the 40x50 and larger would take up to much room to do all large large tray.

[bob carnie]

Ok here is a couple of pics of the bottle washer guy with the scrolling set up.
hope it clears up my above post

[SeanEsopenko]

Ok here is a couple of pics of the bottle washer guy with the scrolling set up.
hope it clears up my above post

Looking at the above photos, it's rolled image facing inwards? Do you roll it only once around or is it ok to roll it multiple times, doubling up the layer in the roll? It appears as though you wouldn't want to cover the image surface with paper and it would be important to have enough blank paper on the trailing edge of the roll to prevent it.

Do you submerge the entire thing as you're performing the rolling or do you let it sort of "skim" through the water, almost like a water mill?

Thanks a ton for the explanation Bob. I think I have enough information to make an attempt at it. Maybe this weekend if I can find some makeshift "troughs" I'll have a go at it.

[IanG]

Another method and the one I use more (in recent years) is sponge processing. After exposure I tape the paper to a large sheet of plastic, this drains into a trough, I then use a sponge to gently apply developer which is used more dilute to increase the development time.

I apply the stop bath and fixer the same way, but will use a large darkroom sink for final (second) fixing & rinsing, washing is done in a bath.

When I had a large darkroom large conventional prints were processed by hanging on a board spraying the chemistry which was surprisingly economic.

Ian

[jon.oman]

I worked for Ford Motor Company in their Reprographics department. We did the same thing as Bob describes. Our materials were up to 52 inches wide, and 22 feet long. You just have to have a lot of chemistry in the narrow trays/tanks, and learn to move the material without damaging it.

[bob carnie]

Sean
I would always reverse the roll for more even agitation.
I roll it once and then turn it, get some blank paper and try it and you will see that you have to do this otherwise you would roll away from yourself, I roll into myself.
notice the chemical suit It is needed.
I use the digital fibre and regular, with the digital it is red sensitive so all operations are in total darkness. After two times you will be a pro, believe me . looks harder than it is.
Image surface is always away from me in the roll , chems get on the emulsion very easily.
Submerge the entire thing, basically you will find it sits half in and half out of the chems and just start scrolling. the liquids do the rest. See how my hands are on the edge very important.
Also remember do not skimp on chems or all bets are off at my end.


Looking at the above photos, it's rolled image facing inwards? Do you roll it only once around or is it ok to roll it multiple times, doubling up the layer in the roll? It appears as though you wouldn't want to cover the image surface with paper and it would be important to have enough blank paper on the trailing edge of the roll to prevent it.

Do you submerge the entire thing as you're performing the rolling or do you let it sort of "skim" through the water, almost like a water mill?

Thanks a ton for the explanation Bob. I think I have enough information to make an attempt at it. Maybe this weekend if I can find some makeshift "troughs" I'll have a go at it.

[bob carnie]

I hate bigger rolls as I am a short ass and my arms barely make the 52 inch.

I worked for Ford Motor Company in their Reprographics department. We did the same thing as Bob describes. Our materials were up to 52 inches wide, and 22 feet long. You just have to have a lot of chemistry in the narrow trays/tanks, and learn to move the material without damaging it.

[jon.oman]

I hate bigger rolls as I am a short ass and my arms barely make the 52 inch.

:) :) :)

My boss was a man who was short (about 5 feet 5 inches). I could never keep up with him! He had a way to do it that was all his own.

[Vaughn]

Our intermediate photo class are making mural prints this morning -- 40" x 60". We have a couple troughs on the floor and with a student at both ends of the print, it is see-saw'ed through the trough.

Sort of reminds one of two people pumping one of the hand-powered railroad carts. The students each make one print (it is combined with a 4x5 self-portrait assignment). They only get one chance so no room for errors. I'll show the prof the images of Bob working and see how he feels about that method!

Vaughn

[ic-racer]

I was looking at these Hog-feeding troughs a while back but they have very large volumes.

http://img.photobucket.com/albums/v670/ic-racer/longline-troughs-feed-sm1.jpg

[jon.oman]

I'd go with flat bottom troughs, but then, that is what I used.

[Ed Brock]

I use "trough" printing on a regular basis for 20x24 paper. I place the print in a 6" black ABS cylinder (available at Lowes as drainpipe and sold in 24" lengths) and just tilt my trays enough for the chemistry to cover some of the photo paper in the bottom of the hand-rotated cylinder. The results are always perfectly uniform and it uses very little chemistry (24oz. for 20x24) in my case. In reality you can only get around 19" width in the tube before it begins to overlap on itself. OK in my case because my usual 5x7 format enlarges to around 18x24.

[Fred L]

and here I am thinking I'm the only one to consider the under bed storage containers :)

[SeanEsopenko]

Thanks for all the advice everyone. I think I have a good understanding of how to do it.

The advice with the ABS pipe sounds almost exactly like what I need.

[dsphotog]

I've used inexpensive wallpaper troughs, they work with about 1 gallon of chem.
Their only weakness is they are kinda thin so I double them.

[Bruce Douglas]

I agree with Jon that you might consider using a print drum. 20 years ago I processed 32x40 sheets of paper in one I made out of a piece of green plastic sewer pipe. I put a drain in end which I could plug. Made removable end caps out of rubber sheet.

I built a platform with four casters on which I could roll the pipe back and forth for agitation. The platform could also be tilted to drain the drum at one end.

The paper was placed inside the drum dry emulsion side out, the end cap replaced, chemistry added and the process begun. It was kind of like single tray processing.

To wash the prints, I removed an end cap, separated one edge of the paper from the inside of the drum and rolled it onto itself. I could then lift the rolled up print out of the drum without kinking the paper.

I placed it rolled up into my washing tray, unrolled it and let it wash the required time.

If this is of interest to you I can likely come up with some pictures of it in the next few days. I have all the pieces, I just have to gather them up. Let me know if it would help you to see it.

Take care,

Bruce Douglas:)

[frotog]

A semi-cylindrical trough will make scrolling much more difficult as the leading scroll and the feeding scroll will have a tendency to come together - you want to keep them apart. Also, you want both ends of the scroll to be semi-submerged in chemistry. This would be very difficult without using gallons and gallons of chemistry and a massive three foot diameter round bottomed trough. Use a flat bottomed trough instead as not only will you use a lot less chemistry but the bottom surface of the trough is necessary for the scrolling action that moves the print through the chemistry/water wash.

With all due deference to those who have succeeded with their respective techniques, I'd like to point out a few alternatives to what has already been posted...

Hands down the most difficult aspect of making murals is keeping from crimping the print. If the print stays in a roll it is less likely to crimp. When you pull the paper off the roll, roll it up before cutting it. From here on out the only two times you should have to lay the paper flat is for exposing and hanging to dry.

With a light touch and gloved hands it is far easier to scroll the print from the center rather than the ends. This way allows you to scroll in both directions (easier on your neck and back too;) ).

I never use more than a gallon of chemistry because...
a) It's not necessary.
b) I'm working in a small drkrm. with a 11' x 28" sink, can only fit two troughs...the second trough serves both stop and fix so the stop needs to be dumped. Do you know what it's like to lift and dump a 54" tray with a gallon of chemistry? Not so difficult. What about 35 litres of chemistry? Not a chance.
c) The deeper the bath, the greater the drag, the slower the scroll and the more likely you'll crimp the print.
d) I get full agitation due to the speed of my scrolling action (a full scroll in 10 - 15" depending on the length of the mural) and can thereby achieve shorter development times with full development (e.g. 2') when necessary.

I use developer and stop as a one shot, the two fixing baths will last me for two 40x50's. In the fifteen years I've been doing this I've never had issues with uneven development. The only time I've had issues with crimping was when I've hired people to help out in the process.