PDA

View Full Version : Cibachrome Drums: What quantity chemicals?



SpeedGraphicMan
1-Mar-2012, 14:07
Hello all!

I just puchased an entire set of Cibachrome drums.

Sizes 4x6 through 16x20.

What I need to know is what the minimum recommondation for RA-4 chemical quantity is for each tube?

Also, as I intend to use the 4x6 drum for sheet film processing only... What would be a good quantity of D-76 1:1 for 1 sheet of 4x5?

Thank you all in advance.

Roger Scott
1-Mar-2012, 16:43
For Ilfochrome the minimums were 75ml for 8x10, 150ml for 11x14 and 360ml for 16x20 drums. These were doubled for the transparency materials. There's no mention of 4x6 in my booklet. You'd need to check the RA-4 chemical specs to ensure you have enough but this should give you an idea of coverage requirements for the drums themselves.

Fotch
3-Mar-2012, 11:05
I have a couple of new old stock 4x5 print drums still in factory package with instructions. It does not state what the volume of chemicals to use. Probably what ever the minimum of chemicals needed for the square inches of paper would be my guess.

Drew Wiley
3-Mar-2012, 21:29
Depends on the specific chemistry, agitation rate, and most important,
on how level the drum is running. I find 8 oz of RA4 more than sufficient for a 16X20 print, but you might start with a bit more and work down.
An 8X10 test print requires only 1-1/2 to 2 oz for one-shot use. But this is
also related to ambient air temperatures and preheating the inside of the drum with water before adding actual developer. Obviously, too much cold
air inside and you need more chem to offset it. Helps to have the room
temp reasonable.

Roger Scott
3-Mar-2012, 21:44
One thing I should add is that the Cibachrome drums might require more chemistry than an equivalent sized Jobo drum as they don't have the ridges you slide the paper into (at least mine don't) which helps to keep the paper near the outside of the drum. It'll depend on the paper of course as some thin papers will be bendy enough to "stick" themselves to the outside anyway once wet.

Drew Wiley
3-Mar-2012, 21:50
No ridges equates to less chemistry, as long as the entire print is kept wet
during rotation. I've done up to 30X40 in smooth drums. Never a problem.
But you do have to make certain the back of the print is well washed after
the blix. This can be done in a tray or conventional print washer.

sully75
3-Mar-2012, 22:51
I think one thing I missed when I started is that I was putting too much chemicals in the drum, thinking more was better. Now I'm thinking it's better (the way the drums were designed) to have no part of the film touch the drum when the chemicals go in. They should only begin to touch the drum when the rotation has started. So...the manufacturers suggestions are a good place to start. I don't have cibachrome drums, just unicolor and chromega.

Roger Scott
3-Mar-2012, 23:52
No ridges equates to less chemistry, as long as the entire print is kept wet
during rotation. I've done up to 30X40 in smooth drums. Never a problem.
But you do have to make certain the back of the print is well washed after
the blix. This can be done in a tray or conventional print washer.

When doing 8x10 Ilfochromes in an 8x10 cibachrome drum the cpm-1m paper I used wouldn't bend to the curve of the drum. It's more of a problem with smaller prints than larger ones.

fsibold
4-Mar-2012, 17:21
I processed 4x5 film in an 8x10 cibachrome drum. First I put the 4x5 sheet in a tray full of water. Then I put the sheet in the tank. I used 80mL of HC110, dilution B.
I tried to process 2 or 4 sheets at the same time in the drum : sometimes a sheet slips on another one.