RBM liquid emulsion

[Paul Eyes]

I am doing a huge 12x15 foot liquid emulsion print on canvas , if you have any advice for me it would be greatly appreciated . First I will paint the canvas with Gesso and then sand it down and repaint it until I have a smooth texture free serface. Then I will paint over that with white glossy polyurethane paint or alkyd primer. What do you recommend more ? becuase of the size I will have to roll it up to transport it , I assume it will not crumble or break if it's slight tolled up afterwards . Not tightly rolled just a big roll to get it through the door. I am using Dekto for a developer, but should I put some RBM5 hardener into the developer , or just add some chrome alum into the emulsion ? I will be adding a little spirit alcohol to keep the bubbles down , I will most likely skip the stop, and then add a non hardening fixer, ilford rapid fixer. Then wash . the next day I will selenium tone. Or should I do it during the initial process ? I will keep my chemicals cold , pour then out of a watering can . But my real question to you is how should I applie the liquid emulsion? On such a big area I suppose I will lay it on the ground , and then pour this on and spread it. But I don't want brushstrokes . Or limit as much texture as I can . RBM say not to use a hardening fix. But I will be pouring the chemicals down on this canvas hanging on the wall , so I don't want it to slip off the canvas

 

[Photo Engineer]

I suggest lots and lots of practice beforehand.

PE

 

[Paul Eyes]

I suggest lots and lots of practice beforehand.

PE

I suggest lots and lots of practice beforehand.

PE

thank you I definitely will . I would just like to gather as much info about it as I possible can .

 

[removed account4]

that is a large canvas 12 FEET by 15 FEET
i do not think the problems you will have with be with the canvas.
there are people here who print on canvas and threads talking about that
http://twistedsifter.com/2014/05/worlds-largest-photo-taken-with-worlds-largest-camera/
these folks made a 107FEET by 31FEET liquid emulsion cloth print and developed it
in 600 gallons of dektol and 1200 gallons of fixer in a swimming pool liner
their image is monsterous compared to yours, but maybe you can get ideas of how
to develop it from the article .. you'll need something giant to develop it in ...

good luck !

 

[Paul Eyes]

thanks for that . My plan was to pour the chemicals from watering cans down the canvas hanging on the wall. So that it would gather in a gutter that I made to collect the flowing liquid . The top part of the canvas would still be attached to the wall and I would pull the bottom out so that it's at 45 • degrees and then pour from scaffolding down onto the canvas so that the chemicals flow down and develop it .

 

[eddie]

When I've done something similar, I used soft sponges to apply the developer, etc. If I recall correctly, I used Dektol at 1:4. It was slower, but it gave me time to make sure the development was even. I think pouring the developer (especially at normal dilutions) will cause uneven development problems.
As for the toning, I did it the same day. My prints were only about 4x5 feet, but I didn't want to re-wet them for toning on another day. I thought it would increase the chances of print damage.

 

[removed account4]

i'd be careful pouring with a wattering can at the top and having it trickle down ...
the top will be developped more than the rest and you will be doing it in sections ( unless you have a 10 foot watering can )
and they will devlop at different rates as the rest of the canvas. and then if the canvas is at a angle, you risk pooling your chemistry
and getting over developed regions that way. i can see sponges like eddie said, but you would have to have a lot of people sloshing developer with sponges
at the same time on ladders &c, sounds like a dissaster waiting to happen !
not sure if you have "kiddie wading pools" where you live ... they are round plastic swimming pools for little kids
if you could figure out a way to "weld" the plastic together ( duct tape? uv bonding plastic weld glue ? )
then you could make something big enough to hold your print ... and develop it the old fashioned way in a enormous tray.

sounds like a great project !
john

 

[M Carter]

I've done canvas at around 20x24 and am working towards around 60" max.

First, you have to test the substrate. Do it at like 5x7 due to the expense of emulsion. I use Foma liquid, which is gorgeous stuff. Foma peels off the substrate if not done right. My success has been:

PVA both sides of the canvas - this is pretty big as it seals the canvas and keeps it more dimensionally stable. And the stuff is cheap.

2 coats of gesso and 2 coats of artist's oil ground. Gesso alone and the emulsion came right off. The oil ground takes days to dry. You could likely use an alkyd primer for your size. I was concerned about long-term stability so i used all artist materials vs. house painting stuff. Then a couple coats of spray poly, which I found pretty glossy. Still experimenting to get a solid coating without the poly. Small scraps to dial all this in are a must.

Foma comes with a hardener, which I use.

Cold chemicals are important, I live in TX so our water is hot. For large pieces, I coil a hose in a cooler of ice to cool the wash water. I collect empty cat litter jugs to store chems. (We adopted a really old stray and she is insane. Drinks form the sink all day, so we go through tons of litter).

I'd look into using a thick, wooly paint roller for chemistry, with a home made trough at the bottom of the print. You can make the trough from plywood, seal it with gorilla glue, coat with porch paint. It's not a boat, that should be enough to hold the chemicals. For my size, I'll just make a plywood tray 6' x 5' and actually expose in the tray with a wall-mount enlarger. I'm concerned about fixing and washing adequately, and my tray design has a drain port and hose connection to the house plumbing drain.

But - if you make a trough that big - it may be much better to "see-saw" a print through it with several people. To keep the canvas from buckling, something like a 3 or 4" PVC pipe could be mounted across the trough, half-in the chems, and run the canvas around (under) it, emulsion-side down, and have several people on each side see-sawing it through. Think these kinds of things out...

Pick a cheap RC paper and use it to determine exposure and contrast (if your emulsion isn't VC, get a good 5x7 or 8x10 test that looks good to you with the emulsion. Then recreate the contrast and density on RC. In my case, Foma is about a 3 to 3.5 grade and is not VC, so my neg needs to be more contrasty. I find a close match on Ilford RC - so if my ilford print matches the emulsion print for 20 seconds at F5.6 with a grade 3.5 filter, and the emulsion print was f11 at 20 seconds with no filter, I can reliably begin dialing in an emulsion print 2 stops down from my RC tests with no filter. This can save you a ton of emulsion). You should likely make a big-ass test strip for your final - that is, prepare a 2' x 6' strip and make sure your exposure is right.

For really big prints, I've had luck making an adapter for my enlarger that holds a Vivitar 285 flash. So instead of 90 seconds, it may take three pops of the flash at 1/8 power. I put a sheet of CTO gel in the filter box to make the flash "tungsten" (also cuts a stop or so). I just aim the flash at the condenser bulb and use some black foamcore. I get even exposure this way. You can use an extension cable with a momentary switch or get a cheap chinese radio trigger. Just make SURE nothing in the building is setting the trigger off!

For coating, I like this brush. But for something huge, I dunno... a roller will waste a lot of emulsion and a brush will be hard to get it even. I assume that when I get above 3' or so, I'm going to have to experiment with spraying, maybe multiple thinned coats. I own this HVLP gun ($16 and actually fairly well regarded by auto body guys) and I think it could do well with some testing. HVLP doesn't have much overspray, and you can learn by using things like coffee creamer. Doing coffee creamer tests will also let you figure just how much emulsion you'll need to soften and mix.

I have trouble with even brush coating at 20" on canvas, so I'm experimenting with cutting emulsion with half distilled water & alcohol and doubling coats (Foma calls for 2 coats, so I'd do 4 thinned and see if I get a more even coat).

I'm also leaning towards linen canvas with multiple gesso coats, sanded, to minimize the canvas grain. High spots in the canvas for me have been an issue, the emulsion settles into the texture and I get white spots.

My end-use is tinting with oil glazes and varnishing, I'm going for a sort of "ancient" look that's hard to tell if it's a photo or painting, that uses zero computers or digital processes, all analog. Here's my latest test - keep us posted as to how this goes, but like everyone else has said - start small and work your way up!