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Kevin J. Kolosky
25-Nov-2018, 18:22
Has anybody figured out a teaspoon type measurement system when mixing D-23. I have tablespoon, teaspoons, 1/2 teaspoon, 1/4 teaspoon, 1/8th, and 1/16. I ought to be able to get pretty close to the correct measurements with those.

Just seems it would be easier that measuring with a scale each time.

LabRat
25-Nov-2018, 18:50
If you have a scale, and cups, spoons, etc, you can make your own standards by measuring out your amounts and marking out spoons, cups, etc with a line to fill up to...

I think it not so bad a task as D23 is reused, so not a big deal to mix every few runs...

You can also measure one session and put chems in measured bags to mix when needed...

Steve K

Jim Noel
25-Nov-2018, 19:36
Add a pinch of sodium sulfite to 3 cups water stir until dissolved.
While stirring add 1 1/2 teaspoons metol stir until dissolved
while stirring add 1/4 cup sodium sulfite, stir until dissolved.
Add water to make 1 Liter or 1 QT.
Note: if the pinch of sodium sulfite is too large, or small the metol will not dissolve.

Kevin J. Kolosky
25-Nov-2018, 21:44
Thank you Mr. Noel.

mdarnton
26-Nov-2018, 06:52
Here's a ray of hope for you: for decades, literally, I made D23 following a kitchen spoon recipe from, I believe, a 70s article in Camera 35 magazine. Sometime within the last 10 years or so I bought a nice scale and actually weighed the chemicals I use (brands aren't consistent, and I imagine there's packing over time), and discovered I was way off. From then on I used the scale, and the results weren't that different, nor were the times. With this particular developer precision may not be too important.

But with a nice electronic gram scale costing six bucks, post included, on Ebay, I don't know why you'd insist on using a fundamentally flawed method. When I weigh now, I put a small plastic cup on the scale, tare off the cup, and just start adding ingredients to the cup, counting up from zero. It's no fuss at all.

Kevin J. Kolosky
26-Nov-2018, 08:29
Which Brand scale do you recommend?

Joe O'Hara
26-Nov-2018, 09:59
I have a little Ohaus scale that is very nice. Less than $100. I'd recommend a scale that resolves to 0.1 g.
Those usually max out at 200 g. You don't want to have 1 g uncertainty if you're trying to measure 3 g of
something. (Regardless of the stated accuracy, digital readouts inherently have +/- 1 least significant digit
of uncertainty in the displayed quantity.)

On those occasions when I need more than 200 g of a chemical (mixing up a gallon of D-72 e.g.) I just split
the quantity in two and measure them separately.

I've had it for 5 years and it's still on the same set of AA batteries.

You could even get a used one, if you can check and adjust the calibration with a known weight.

It's also a good idea to mix your developers using distilled ("steam distilled", not "deionized") water.
One less variable to contend with.

Peter Collins
26-Nov-2018, 22:07
18 MOhm (MegaOhm) DI water is *the* water used in analysis of constituents using U.S.EPA protocols. You may find some DI water meeting a resistance close to that.... Must be a pretty good level of treatment if it is used in U.S. EPA test procedures.

On a separate train of thinking, any water treated to 1 ppm (part per million) of Total Dissolved Solids (often "TDS") has to make the resulting diluent water a smaller variable than chemical measurement error or temperature change during development. Most kitchen countertop DI treatment systems exceed that level of treatment.

So, Joe O'Hara is certainly correct--one less variable, but I do not expect one would see a difference between steam distilled and DI water in photographic chemistry of the kind used in B+W film/paper development.

Joe O'Hara
27-Nov-2018, 06:46
Thanks for the information, Peter, I didn't know that. I thought that DI water was just run through an ion exchange resin to take out
one set of minerals and replace them with something else, like a home water treatment system. DI sounds like it would be just as good
as distilled especially if it's cheaper in one's area to purchase.

LabRat
27-Nov-2018, 15:11
You should get a scale... You can make a wide range of paper & film developers form just several ingredents, and other formulas... Bulk chem is very reasonable, and you can make some formulas for pennies...

Another source for scales is a pawn shop, as many triple beams and balances are formally owned by druggies, and sell for about $30...

Steve K

Greg Davis
27-Nov-2018, 18:34
Kevin, I use a scale by My Weigh off eBay. Small and inexpensive, but accurate and reliable. They have many different models, but one that measures is 0.1 grams is perfect for the darkroom. One that maxes out at 300 grams in 0.1 increments is about $39 and free shipping.

David Karp
27-Nov-2018, 21:14
I have a My Weigh also. Works just fine.

Kevin J. Kolosky
7-Dec-2018, 06:17
Purchased a My Weigh scale. Works fine. And also have a bunch of Elon and Sodium Sulfite on hand. Gotta figure out a starting development time and temp. for both Tmax roll film and Tmax sheet film. I have a densitometer and could do all of the required tests to establish a black and a white and all of that stuff. But maybe somebody here has a pretty good starting point to recommend and I can just tweak it from there.

David Schaller
9-Dec-2018, 10:30
If you have used D-76 before, I would start with those times. I used to use D-76 1:3, and when Iíve used D-23, also 1:3, the times were nearly the same.