Check my math please

Going to be developing x ray film in Kodak 1 gallon tanks using Pyrocat HD. 1-1-150
Based on my research you need 250ml of working solution to develop one sheet of regular film.

Since this has emulsion on both sides 500ml is needed for each sheet. This mean for one gallon of working solution I can develop 7 sheets of x ray film.

I feel like there is something wrong with my math somewhere but can't quite figure it out.

Plus

Assuming I do 5 sheets in the first go will there be enough time to get the second set of two sheets into the soup before oxidation makes it unusable?

Why are you mixing gallons and milliliters!
Is it a US gallon (most likely) or an Imperial gallon? 3800 milliliters or 4600 milliliters (rounded off)?
If it is a US gallon, your math is correct.
I cannot help you with your oxidation question.

Yes US gallons. thanks. Now the hard part. breaking that gallon volume into the correct ratios.
I'm a former mechanic. I readily mix US and Metric.

mark said:

Now the hard part. breaking that gallon volume into the correct ratios.

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25ml + 25ml + 3750ml

mark said:

...Assuming I do 5 sheets in the first go will there be enough time to get the second set of two sheets into the soup before oxidation makes it unusable?

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I have done one 11x14 negative in a tray with a pyro developer, then developed a second one afterwards in the same tray of developer. I was doing constant agitation, so I imagine that you'll be fine. You should have less oxidation in a tank. You might need to add a little time (10% seems like a good start).

Mark,
You might want to look into x-ray film developer and fixer available from dental/medical supplies. The one I use in my dental practice and for enlarged negatives on x-ray duplicating film runs about $22 for a pair. The mix ratio is 1 quart to 3 to make a gallon. The same for both. If you pour the working solution from the tray into bottles it should be good for about a month or longer. Depending on how much you need to cover your film you might not have to mix the entire bottle of concentrate. Developing time should run about 1 1/2 - 2 minutes but you would have to check for your specific needs.

http://www.jeffreyglasser.com/

jeffreyg said:

Mark,
You might want to look into x-ray film developer and fixer available from dental/medical supplies. The one I use in my dental practice and for enlarged negatives on x-ray duplicating film runs about $22 for a pair.
http://www.jeffreyglasser.com/

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Jeffrey,
I never considered using X-ray developer and fixer. I have not shot a sheet of x-ray film yet either, so I am open to lots of suggestions. I had chosen Pyrocat because it had a hardening effect on the emulsion and which, according to my reading helped avoid some scratches. It is also a developer I have experience with.

Having no hands on experience with X-ray film my knowledge comes from reading here and the LFphotography.info form. It is my understanding the X-ray film is very contrasty but there is some control with developer. Is this the case and what effect does the short development time of x-ray chemistry have on different tones?

Are all of the photos in your galleries enlarged onto x-ray film? How are you printing them. I am aiming to learn as much as I can because I am planning to take sheets into the field in a couple weeks to experiment with.

I wouldnt use x-ray chemicals unless you are taking x-rays.

Mark,
The film I referred to is x-ray duplicating film which is a reversal film that I use to make enlarged negatives for platinum/palladium printing. When making an enlarged negative the exposures are fairly long and that film is somewhat more contrasty than the original negative but that works well for pt/pd. In my office I use the same dev/fix chemistry to develop x-ray film that was exposed by x-rays. I haven't tried x-ray film in a camera.

http://www.jeffreyglasser.com/

I have used Rodinal with single sided and double sided 8x10 x-ray film and found somewhat surprisingly that the same amount of developer was sufficient for the double sided as for the single sided. My conclusion is that even though there is twice the emulsion, the amount of development is about the same since the desired density is the same in both cases, so one side of the double sided negative would be a rather thin negative. X-ray film is so cheap that it is easy to experiment with it.

jeffreyg said:

Mark,
The film I referred to is x-ray duplicating film which is a reversal film that I use to make enlarged negatives for platinum/palladium printing.

http://www.jeffreyglasser.com/

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Ok. This makes sense.

ewbank1 said:

I have used Rodinal with single sided and double sided 8x10 x-ray film and found somewhat surprisingly that the same amount of developer was sufficient for the double sided as for the single sided. My conclusion is that even though there is twice the emulsion, the amount of development is about the same since the desired density is the same in both cases, so one side of the double sided negative would be a rather thin negative. X-ray film is so cheap that it is easy to experiment with it.

Click to expand...

Thanks. This is good info to know. How are you avoiding scratches?

It is difficult to avoid scratches. I first tried rotary tube which resulted in lots of scratches. I had some luck with tray processing of one sheet at a time. Decent luck with hangers in deep tanks and also with a JOBO expert drum. But I never really had a consistent scratch free process.