What's another word for "fluid" ounces?

[William McEwen]

So long as you don't hit my left arm, being hit by a car on monday left it damaged enough!

Youch! Sorry to hear that. Was it some crazy American driving on the wrong side of the road?

[Howard Tanger]

...


When I was in engineering school way back in 1902...

Bruce, that would make you at least "108 years old" this year??? Howard

[Heroique]

Whoops. Bruce meant 1920, not 1902.

...I'm going to let the lady at PF calm down a little before I call her back...

Forwarding Bruce’s excellent reply will do the trick, and enlighten their customer service.

[J D Clark]

I'm a chemist by training (Ph.D., 1986), so let me clarify. Even if you measure a powder in a graduate, and declare the number of "ounces by volume," it could be a wildly different amount from a different powder of the same chemical. The difference comes from the size and packing of the granules.

So, powders are measured by grams, or ounces (as in, 16 ounces in a pound). Liquids are measured by liters or milliliters, or ounces as in 32 ounces in a quart. The two types of ounces are correlated in only one way: one fluid ounce of water weighs one [solid] ounce. For other materials, it's not necessarily the same.

That said, the concentration for hypo is not that critical. So, for Barry's formula above (240 grams diluted to 1L water), for the metric-adverse, it's roughly equivalent to 8.5 ounces (from a balance) in a quart of water.

John Clark
www.johndclark.com

[J D Clark]

In earlier posts, I complained about no longer being able to get the pre-measured packets of Zone VI hypo and hated the fact that I'd have to buy a scale. I want less equipment, not more!

So, clearly I type a lot slower than Bruce! Anyway, you don't necessarily have to buy a scale. The exact quantity for this fixer is so non-critical that I believe you could use five handfuls of hypo, or if two heaping tablespoons equal a "handful," then 10 heaping tablespoons.

Some photographers just use a big scoop without carefully measuring it. You just want to use the appoximate "size" of the powder that came from Zone VI in the amount of water they recommend -- no balance necessary.

That said, I wouldn't formulate developers that way...

John Clark
www.johndclark.com

[Eric Woodbury]

"A pint's a pound, the world around."

I know that hypo is denser than water, but over the years, the penta form has been fairly invariant in density and thus volume measures are pretty consistant. I throw a cup of hypo in the tray and add a graduate of water. Seems to work.

[Helen Bach]

one fluid ounce of water weighs one [solid] ounce.

Only for imperial fluid ounces, if you wish to be dead-on accurate. The slightly larger US fluid ounce of water has a mass ("weight" if you prefer) of 1.041 ounces ("avoirdupois" ounces, which apply to solids, liquids and gasses). None of this matters much really.

Best,
Helen

[Gem Singer]

Hey William,

Read my post again. I didn't say pre-packaged. I said pre-mixed.

Such as: Photo Formulary Pyrocat-HD Developer in Glycol, TF-5 Alkaline Fixer(in 1 gal containers), and Formaflo Wetting Agent.

I recommend purchasing bulk chemicals from a chemical supply company instead of the Photographer's Formulary.

[J D Clark]

Only for imperial fluid ounces, if you wish to be dead-on accurate. The slightly larger US fluid ounce of water has a mass ("weight" if you prefer) of 1.041 ounces ("avoirdupois" ounces, which apply to solids, liquids and gasses). None of this matters much really.

Best,
Helen

Doh! Of course. Scientifically, we always use grams and milliliters -- much easier. No wonder everyone ends up confused. In any case, the difference between an imperial ounce and a US fluid ounce doesn't make a difference here, and I stand by the "coupla' handfulls of hypo" method...

John Clark
www.johndclark.com

[Robert Hughes]

I stand by the "coupla' handfulls of hypo" method...

Not me! I just got a gram scale at a local yard sale - for $2, yeah. Now I need to figure out how to drive it...