im tired of grams and would rather use a teaspoon

darkroommike · Sep 6, 2016

jnanian said:
hi alan

...
i am thinking of converting a pickle jar for a storage container that i will keep 1gallon's worth of
D72 chemistry in and shake it up constantly to get it all mixed and figure out how many "scoops"
of whatever i am going to use / volume of water will work out. so i don't have to have it mixed all the time...

darkroommike · Sep 6, 2016

That's quite a different thing from just mixing D-72 (or whatever) volumetrically, I tried the scoops method when I got lucky with some free 25 gallon mixes of Ektanol, and it worked OK but keep in mind that all print developers work pretty much the same so a bit more of this or that per scoop may not matter that much. MAYBE.

Factory Kodak developers are one part, Ilford developers containing metol are made in 2 parts and you mix the metol before you add the remainder of the ingredients. Your homebrew developers, if they include metol, will probably not mix properly, metol is reputed to not mix well in a higher concentrated sodium sulfite solution. I suspect that Kodak treats the sodium sulfite in it's pre-packaged developers so that it dissolves slowly, in effect the sodium sulfite dissolves after the metol is already in solution.

You could, with a little more work, make up a batch of D-72 without sodium sulfite, scoop and stir up what you need and then add a scoop of sodium sulfite. Or make up a bunch of packets that mix up to you usual volume of soup, measuring out separate parts A & B. If you do 8x10's a convenient amount might be 2 liters working solution and if doing 11x14's just make up a double batch.

It would work but in my opinion it sounds like more work than breaking out the scales. I make a gallon (or 4 liters) at a time and divide it into smaller bottles. Conservative shelf life is 6 months.

Doremus Scudder · Sep 6, 2016

John,

I use a spoon recipe for a low-contrast print developer and wash aid, but weigh out almost everything else. While weighing is inherently more accurate, there are ways to make spoon recipes fairly accurate.

First, buy chemicals in bulk and spend a bit of time determining the weight/volume ratio for that batch. Then keep the chemicals tightly sealed and well-stored when not in use. Use chemicals that require larger amounts for making up solutions; there's less chance for error. Don't buy chemicals that are hydroscopic and will change volume/weight with time.

Finally, mix stock solutions of stable chemicals, especially those used in small amounts, so you can measure them out with a graduate or syringe. This is what makes life easiest for me. I use PMK, so just measure out the needed quantity with a syringe from stock. Liquid stocks of stop and fix are easy to mix as well. Maybe you can make up some stock solutions for the chemicals you use for your processes as well.

How accurate your measurements need to be is dependent on the specific formula; some can tolerate a wide variation, some not, so gravitate to those formulas that are more forgiving.

Best,

Doremus

Helinophoto · Sep 6, 2016

Well, someone did something, before the German recipes appeared, Caffenol was a real mystery.

They even started to convert the German recipes back to US cups and tea-pans and people started getting funny results ^^

"It's not working very well with most films after all" aaaargh!

removed account4 · Sep 6, 2016

Helinophoto said:
Well, someone did something, before the German recipes appeared, Caffenol was a real mystery.

They even started to convert the German recipes back to US cups and tea-pans and people started getting funny results ^^

"It's not working very well with most films after all" aaaargh!

mysteries are good !

weird it doesnt' work with most films
i haven't found a film that doesnt' like drinking coffee ...

Helinophoto · Sep 6, 2016

I was paraphrasing the general mood before the German recipes appeared, I know the German recipes work, it's just sad people tend to think it doesn't based on teacups and whatnot.

John Wiegerink · Sep 6, 2016

I have used these for measuring gunpowder for reloading and they work great. I also have a very sensitive scale for when I'm loading strictly for target shooting, but for hunting and general use rounds these Lee powder measures are fast and very accurate. I found they work best as a dipper and then use a card(like a business card) to scrape the top level. Also, chemicals like metol won't harm the Lee measure like they do metal measuring spoons. here's a link:

Doremus Scudder · Sep 6, 2016

Gunpowder is manufactured to have a homogeneous consistency and is therefore very suited to measure by volume. Powdered chemicals are not so regular from company to company or batch to batch and change sometimes with age and water absorption, making things a bit more complicated. However, testing batches as I mentioned above and proper storage ameliorate this problem to a great extent.

Best,

Doremus

BrianShaw · Sep 6, 2016

... water absorption... I was about to mention that. When baking humidity is the biggest problem with volumetric measure of flour. I assume it could be a problem with some photographic chemicals as well. Ferric (or is it ferrous) ammonium citrate comes to mind. It has been a while since I've done cyanotype but I seem to recall that as being rather hygroscopic.

Sirius Glass · Sep 6, 2016

I easily switch back and forth from metric to U. S. Standard. It is like being bilingual.

StephenT · Sep 6, 2016

Once upon a time, Popular Photography had an extensive article about using volume measure rather than weight. I believe it was in the '70's or '80's. The theory was to save money by only mixing from powder the chemicals you were going to use in a short period of time.

The article included equivalency tables. Of course, they didn't take in to effect differences in molecular weight, etc.

I used the method for a short while, and, of course, discovered that some of the opened powder packages would deteriorate.

This method has been discussed on forums before, and the conclusion, as I recall, is that for many reasons, it is not a recommended practice. I would concur. If you want to give it a try, perhaps an archive search of the magazine will give you some starting points.

frank · Sep 6, 2016

I use weight for solids, volume for liquids.

M Carter · Sep 6, 2016

My wife was having some issues with baking. One day, she got all the measuring spoons and cups out and compared them.

No standards at all, at least for consumer goods. 1 cup in the stainless was actually about 1.25 in the pyrex. So I'd want to be sure your teaspoons are accurate!

Calibrate-able scales and graduated labware are your friends for any chemistry that isn't "horseshoes and hand grenades" - and there are many processes that don't need total accuracy when you look at how dilute the end products are. For developing film, you probably want more accuracy, and repeatability.

John Wiegerink · Sep 6, 2016

Doremus Scudder said:
Gunpowder is manufactured to have a homogeneous consistency and is therefore very suited to measure by volume. Powdered chemicals are not so regular from company to company or batch to batch and change sometimes with age and water absorption, making things a bit more complicated. However, testing batches as I mentioned above and proper storage ameliorate this problem to a great extent.

Best,

Doremus

I treat reloading the same way as mixing photo chemicals. For trying to get groups under 1/4 in. I rely on a very, very accurate scale for weighing powder, bullets and cases since a variation in one of those three will throw the whole thing. I would use the same scale for mixing developers that take agent like phenidone since it would take an extremely small dipper for that and accuracy with that small amount is very critical. Mixing something like D23, D76 DK50 etc. would be just fine with the dipper method. At least for me anyway. As to hydration or moisture absorption? That's a problem whether you use volumetric measurement or the best scale in the world. Some things are just plain close enough and others aren't. You have to decide which one you feel comfortable with. Mixing Pyrocat-HD? I'll measure it on a scale...................Mixing home-brew Perceptol? Dippers are plenty good enough for the girls I go out with.

bsdunek · Sep 6, 2016

John Wiegerink said:
I Dippers are plenty good enough for the girls I go out with.

Ohh, glad I didn't go out with those kind of girls.

Sirius Glass · Sep 6, 2016

M Carter said:
My wife was having some issues with baking. One day, she got all the measuring spoons and cups out and compared them.

No standards at all, at least for consumer goods. 1 cup in the stainless was actually about 1.25 in the pyrex. So I'd want to be sure your teaspoons are accurate!

Calibrate-able scales and graduated labware are your friends for any chemistry that isn't "horseshoes and hand grenades" - and there are many processes that don't need total accuracy when you look at how dilute the end products are. For developing film, you probably want more accuracy, and repeatability.

The difference is that the stainless steel cup is for dry measurements and the Pyrex is for liquid measurement. [Another reason to stick with the metric system.]

John Wiegerink · Sep 6, 2016

bsdunek said:
Ohh, glad I didn't go out with those kind of girls.

Hey, you don't know what you've been missing until you do.

Photo Engineer · Sep 6, 2016

John, which teaspoon? Which sample of chemical? They vary in size of spoon and crystal.

PE

Patrick Robert James · Sep 7, 2016

I am only careful weighing chems with film developers. The developer components of print developers I weigh semi carefully, but the other parts I don't. I use a teaspoon for stop bath and bleaches. When I mix sepia toner i don't even bother with the teaspoon. I just pour some sulfide into the tray. Doesn't matter.

rpavich · Sep 7, 2016

And all this so that you dont have to pull the scale out?

Seems like the cure is worse than the disease.

David Lyga · Sep 7, 2016

What I neglected to say with calibrated cylinders was this: It is true that the 'precise volume' changes if you tap down that powder. However, I have a specific way of doing this measurement, in that I tap down a bit, but not intensely. I tap down maybe once or twice, gently. Doing this, consistently, makes this method rather accurate and consistent. - David Lyga

removed account4 · Sep 7, 2016

rpavich said:
And all this so that you dont have to pull the scale out?

Seems like the cure is worse than the disease.

i'm starting to think so too,
it seems like the medication for a runny nose
whose side effects include liver+kidney damage, blindness and death.
maybe i need a bigger scale

LOL

BrianShaw · Sep 7, 2016

There's on old adage to recall at this point in the conversation: If there was a better way it probably would be commonly used already.

Of course, this isn't always true but often it is.

removed account4 · Sep 7, 2016

Photo Engineer said:
John, which teaspoon? Which sample of chemical? They vary in size of spoon and crystal.

PE

hi PE

i have a set of plastic measuring spoons i purchased just for the darkroom
they go from 1/8tsp to 1tbs. as for sample chemicals ...
the darkroom cookbook page lists most everything i had planned on using

i'm thinking ...
potassium ferricyanide
potassium bromide
HQ
metol
glycin ( maybe )
washing soda,
instant coffee
vit c
sodium sulfate ( and ite )
sodium thiocyanate
permanganate ( maybe )
sodium thiosulfate
sodium chloride
gelatin
i don't i plan on using anything else

thanks
john

Photo Engineer · Sep 7, 2016

John, my point was that right now you may be using powdered KBr, but next time you get cubic crystals (I have a jar of each) and these vary by quite a bit in weight vs volume. There was a long thread on this in which I posted photos of the crystals and powder.

PE

im tired of grams and would rather use a teaspoon

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