One simple question for 4x5 Combiplan dev tank newb

Quick and simple. Can I process 12 sheets at a time by placing two in each slot back to back (emulsion sides out)? Read all the other posts to answer my other questions. This is the only one I have left.

In advance, you guys still rock.

Oh, and I only have one tank so if you guys have any special tricks that would be cool too.

You can do 12 sheets that way, but I don't know that it's advisable. Make sure you practice loading them in the light first. It's very easy to get two in the same slot when trying for one each, so doubling up has to increase the odds of a story for the darkroom mishaps thread.

Thanks, Bethe.

I think in the instructions they suggest putting some kind of mesh between the two sheets so the don't become permanently attached to each other. I'll have to check my instructions when I am not half asleep!
I am usually satisfied with only processing six at a time in my Combi Plan.

gene

You can do it, but after fixing, you need to separate them and fix more and wash separately to clear the color from the film.

Jon

papagene said:

I think in the instructions they suggest putting some kind of mesh between the two sheets so the don't become permanently attached to each other. I'll have to check my instructions when I am not half asleep!
I am usually satisfied with only processing six at a time in my Combi Plan.

gene

Click to expand...

Thought it rather odd. Got it from Arista and there are no instructions in the box. Assembly was, admittedly, more trial than error but a little help would have been appreciated. Know what I mean?

I'll probably stick to 6 then. KISS, huh?

Make sure the curved slots are facing inward and only push the clip down a click or 2.

Jon

Figured that and that the straight slots were for plates. Thanks, John.

I am playing around (no conclusions yet) on loading film in my Combi back to back to double up the processing rate.

However, I am using drying screen mesh (you could also use fly screen mesh) to keep the two sheets back surface separate.

There is an anti-halation layer on most sheet film - so the chemicals need access to it to remove it.

I don't use TMax - but if you are, you may find more difficulties with getting it fixed properly.

After playing around in the light, loading 6 off sets of double film sheets seems to be a bit risky (or rather too risky for me) - so I load the outer and inner slots on each side and leave the middle slot empty.

Two sheets of film and an intermediate spacing screen make the film considerably stiffer to load - so make sure the guide slots are nice and smooth - I can see problems with scratched film emulsion without extra care.

I use ID11 at 1+1 - so I have plenty of developer capacity but you might want to check the date sheets for what ever you are using.

Make sure you wash your films properly - there is only going to be a very flow through the mesh - I am working on the minimum of at least doubling the washing routine - I'd hate to find in a few years time that I have skimped.

Good luck

I’d be interested on hearing your experiences

Martin

Christopher, start with processing 6 sheets until you can do it in your sleep. Btw, start with practicing loading blank sheets/duds until you feel that you are very confident with that. The CombiPlan is a good device, but practice is indeed needed.
Also, when you have less than 6 sheets to process, load the empty slots with blanks, so that the chemicals circulate in the same way.

When you are past confident with 6 sheets (i.e. maybe 20 times maybe 100... Yes, I'm serious.) you can start with 12 sheets. I'm not sure if some kind of mesh will help, but that is your choice. Even with a piece of mesh (which means something extra to fiddle around with in the dark), there is a good possiblity that there will be leftovers from the anti-halation backing.
Now, it was a bit of revelation to me to read up on the BTZS tubes some 10-15 years ago. I'm thinking about the bit where they take simply take off the lid and drop the now lidless tube into a bowl with stop bath, where they are collected until you've done with all the tubes. Only then you continue with the fixing part.
So what was the revelation regarding the CombiPlan? Well, one of the downsides with the CombiPlan is that it takes ages to drain and refill. So I got me a couple of jars which were somewhat similar in shape to the CombiPlan tank. I filled those with stop-bath and fixer and had a go with some less important pictures. After my e.g. 10 minutes of developing I switched to the red darkroom light and simply ripped the lid from the CombiPlan and lifted the holder over to the stop-bath container. After a minute I continued with the fixer. Indeed it worked, even though I was somewhat stunned. There was no sign of light damage what so ever.
I later skipped the third container and took the films out of the holder and into an ordinary 5x7" tray with fixer.
I've been using this procedure for developing sheet film for 3-4 years without any traces of light damage. Nor have I had any unpleasant surprises with any 35mm or 120 film when I've done similar things. (Nowadays I use a Jobo CPP2 with Expert drums.)
Anyhow, if you feel that this is a way to go, you will not have any problems with clearing the backing of the films.

//Björn

Wirelessly posted (BBBold: BlackBerry9000/4.6.0.297 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.0.0.0)

I might try this then. Dev in tank. Pour dev into graduate and the stop into tank. Then from stop to tray with fix. I'll see. Thanks for all the answers guys.

In my experience, the films sometimes get scratched when loose in a tray.

Jon

Martin Aislabie said:

I am playing around (no conclusions yet) on loading film in my Combi back to back to double up the processing rate.
Martin

Click to expand...

This would double the film surface area to 240 sq. in. Is the 40 oz. capacity of the Combi tank sufficient for this?

bobwysiwyg said:

This would double the film surface area to 240 sq. in. Is the 40 oz. capacity of the Combi tank sufficient for this?

Click to expand...

Bob, of course it depends on your choice of developer

ID11/D76 & XTOL which I use are both fine.

I use my dev at 1+1 and so use 500ccs of developer per batch - which for ID11 gives me the capacity of 400 sq inches of film surface (10 sheets of 10x8 = 800sq inches x 0.5L)

8 sheets of 5x4 have 160sq inches of film surface.

Even if you managed to do 12 sheets in a tank you only have 240sq inches of film surface.

1L of XTOL has the capacity to develop 15 sheets of 10x8 film

However, if I were using Ilford Perceptol - which has a much more limited development capacity at 4 sheets of 10x8 per Litre of neat stock - I would have to limit myself to 8 sheets.

If you look at your developer manufactures data sheets they have the surface area of film each 1L of neat stock can process.

Note:- 1 off 135-36 film has the same surface area as 1 off 120 roll of film and 1 off 10x8 sheet (or 4 off 5x4 sheets) - they all come out at 80 square inches of film surface.

Hope this makes some sense

Martin

Martin,

Yes, it makes sense, thanks. Some time I will have to get up the nerve to try and load 12 sheets.

Capacity for a gallon of HC110 at Dil 'B' is 20 sheets of 8x10. That would be 75-80 sheets of 4x5. 15-20 sheet of 4x5 for each litre/quart. So the capacity of the tanks would cover 12 sheets in HC110 Dil 'B' but it would definitely be a one-shot.

Dil 'A' would make it a two shot but could drop dev times below 5 min which is not recommended.

I've developed 12 sheets of black and white film in the combiplan... it works but you have to separate the sheets after fixing and wash them six at a time to completely clear them.

I haven't tried color film and likely won't, color film and developer costs more so I don't mind taking my time.

I would not do that.

washing can cause fix to stay between two sheets which will cause problems after years...

Besides that a neg which its emulsion is located against the reel can have develop marks at the long sides of your neg because of the adhesion of the plastic with the neg.

What I did is, I bought another tank...