View Full Version : volume displacement

Calamity Jane
13-May-2004, 12:45
Howdy group; it's me again with nuther strange question .....

I got my HP Combi tank, which holds 1.050 L of solution.

The Agfa C-44 comes in 500 mL ($18) and 5 L ($100) volumes.

I'd like to put something in one side of my tank to displace 550 mL so I can develop 3 sheets of 4x5 in 500 mL of solution. I don't do enough processing to justify making up 1 L and letting it expire on the shelf.

What can I use to displace this volume? It needs to be denser than water, not soak up chemical, and be something I can shape to fit the tank.


John Cook
13-May-2004, 12:59
Hi Jane,

I switched to Combi tanks a few years back. Great success with B&W chemicals. I use Eugene Singerís multiple open-tank method, explained and illustrated on the other side of this site.

My tanks, however, hold 1200ml of solution. With experimentation it is possible to get away with slightly less chemical and still keep the films fully immersed.

But I donít think it is possible to cut it back to 500ml. Problem is, the tank is too full of hanger hardware for there to be room for a spacer of any kind.

Jim Galli
13-May-2004, 13:00
Jobo 2500 system tank with the 4X5 reel is the better solution. Sorry 'bout that. Meanwhile, how 'bout H2O in a zip loc sandwich baggie.

13-May-2004, 13:05
Pop bottle full of water? Taped to the inside of the tank.


His 6.5litre C-41 kit is less then $40 US with shipping any place inside North America. I forget if you'll get hit by GST.

Calamity Jane
13-May-2004, 13:28
Jim, yer a GENIUS!

(Knew somebody here would have a birght idea!)


Gem Singer
13-May-2004, 13:41
Hi Calamity,

It doesn't need to be denser than water. Try a one quart Ziploc bag, with plain tap water. Trial and error will determine how much water to put in the bag. Remove as much air from the bag as possible, so that it does not float. Just be careful to make sure the bag does not contact the surface of the film that has been loaded into the opposite side of the film rack.

Try it with scrap film first. Actually, 1000ml of solution is enough to cover the film rack in a Combi-Plan tank. Don't agitate the tank excessively. I've never tried to do what you are attempting, but I cannot see why it would not work.

13-May-2004, 15:05
Plain 'ol river rock would be better - much denser and smaller - just clean thoroughly.

jonathan smith
15-May-2004, 02:49
How about wax? You could melt a few candles and mold them into place while still soft. I think wax would not absorb the chemistry. You could leave it in as part of the tank, and it wouldn't move around like a bag of water would.