32oz Steel Tank Headroom Question

I'm new to developing with steel tanks. I have a (what I believe to be) 32oz Kindermann tank that can hold 4x 35mm reels or 2x 120.

The 4x 35mm reels fit in pretty snug without much headroom. But the 2x 120mm reels have a good bit of room at the top. Enough that I could probably put a 35mm reel in to take up space.

What is the best/correct procedure with that much headroom? Do I fill up the tank to the top with liquid? Does it matter if the reels are sloshing around when inverting the tank? With my plastic patterson tank, you have a clip that you would use to keep the reel in place on the lift rod.

Thanks!

Brad

I like to fill tanks up in most cases so the liquid itself is not sloshing around excessively.

As far as the reels go, if you can fit a 35mm reel in there, do it. Otherwise your agitation will be excessive as the reels slide around. I have a spacer ‘reel’ that’s shorter than a 35mm reel and is designed to fill that space in a Nikor tank but I have no idea who manufactured it (or where I got it, for that matter). A little movement is okay but a lot isn’t so great.

Okay. A 35mm reel does fit, so that would take care of the issue. Thanks!

Best check the volume needed to fill the tank, too -- my experience with stainless tanks and reels is that they require at least 375 ml for each 35 mm reel, so if four will fit, you're at a minimum of 1.4 liters. If there's room for a 35 mm on top of 2x120, your're probably at or above 1.5 l, which is about 51 ounces.

I do plan on checking the volume. But, at least 375 ml per 35mm reel? I have a small stainless tank that holds one reel, and I've only been putting 8 oz into it. So I've assumed about 8 oz per 35mm reel.

I use diluted d76, 1:1.

Don't you need enough liquid to cover the reels, with a minimum of about 4 oz of undiluted d76 per roll of film?

(This may be opening up a can of worms here that I should have left shut)

Donald Qualls said:

Best check the volume needed to fill the tank, too -- my experience with stainless tanks and reels is that they require at least 375 ml for each 35 mm reel, so if four will fit, you're at a minimum of 1.4 liters. If there's room for a 35 mm on top of 2x120, your're probably at or above 1.5 l, which is about 51 ounces.

Click to expand...

That may be true for plastic tanks, but stainless tanks hold less volume of chems.Single 35mm tank requires 225ml or 8 fl oz. 120 tank holds 16 fl oz. My recommendation to the OP is to put empty reels in the tank and fill until just above the reels, and then pour it into a measure to get required volume. If you fill to the top you will NOT get the air gap needed for proper agitation.

Rick A said:

My recommendation to the OP is to put empty reels in the tank and fill until just above the reels, and then pour it into a measure to get required volume. If you fill to the top you will NOT get the air gap needed for proper agitation.

Click to expand...

This is a recommended method, regardless of what tank and reel types you're using. Hard to think of anything more frustrating than having one of two 120 rolls with one edge about half as developed as the other.

punkzter said:

I do plan on checking the volume. But, at least 375 ml per 35mm reel? I have a small stainless tank that holds one reel, and I've only been putting 8 oz into it. So I've assumed about 8 oz per 35mm reel.

I use diluted d76, 1:1.

Don't you need enough liquid to cover the reels, with a minimum of about 4 oz of undiluted d76 per roll of film?

(This may be opening up a can of worms here that I should have left shut)

Click to expand...

The Kodak Datasheet for D-76, recommends 16 ounces of D-76(1+1) for one roll of 135-36

"If you use DeveloperD-76 diluted 1:1, dilute it just before you use it, and discard it after processing the batch of film. Before using the diluted developer, make certain that there are no air bubbles in the solution. If air is coming out of the solution and forming bubbles, let the solution stand until the bubbles dissipate. Don’t reuse or replenish the diluted solution. You can develop one 135-36 roll (80square inches) in 473mL (16ounces) or two rolls together in 946mL (one quart) of diluted developer. If you process one 135-36roll in a 237mL (8-ounce) tank or two 135-36rolls in a 473mL (16-ounce) tank, increase the development time by 10percent (see the following tables)."

There's the can of worms I was worried about. I have read that. What Kodak doesn't make clear is two things. 1) does the small tank table already take the 10% into account? 2) This pdf, which was published in 2017 can't even both to have the right Tri-X time listed on it.

I use the development times posted on the Tri-X data sheet. For D-75 (1:1) at 68 degrees F, I develop it for 9 minutes 45 seconds.

This would then suggest that I should develop it for basically an extra minute? 10 minutes 40 seconds (or so).

Is this what other people are doing? I have never done this.

Even with my patterson tank, which takes 375 ml or 13 oz for one 35mm or 650 ml or 26 oz for 2 35mm, I never followed the add 10% if less than 16 oz per 35mm roll.

mmmm, no can of worms, at least there doesn't need to be...
I think it is important to remember that the times listed in the data sheet are not absolutes, they're only meant to be (very good) suggestions for where to start your testing.
So, the thing is really, are you happy with the results you get following the method you've used? Are your negatives easy or difficult to print? How easy or hard is it to make a print that coincides with what you envisioned?
FWIW (not much because, YMMV) for one roll of Tri-X in the Patterson two reel tank, I use 400ml of D76(1+1) at 20 degC for 10 minutes....it seems to result in printable negatives.

After you've tested your film, developer, and process combination to verify film speed and normal contrast, you'll have made a bigger adjustment than 10% anyway. Do your testing in the tank and with the process you'll use for "production" and you don't need to worry about Kodak's time adjustment.

And if, like most folks, you develop by time and temperature and print by eye, you'll never notice a 10% difference in process time (which amounts to no more than a half grade contrast change at printing time).

D-76 really wasn't developed for what we would now describe as small tanks. It was designed for commercial processing, and adapted to small tanks.
The Tri-X times in J-78 are correct for the CI targeted, and assuming the agitation regime suggested - including adding the reels to the developer, rather than pouring developer into the closed and light tight tank.
As a developer designed to be used in quantity, D-76 requires a work-around if used diluted and in small volumes. There is enough capacity there that one can generally compensate for the small amount of diluted developer by increasing the development time, although I would avoid that if the rolls were full of a lot of high key subjects.
The work-around has not been factored into the table times.