Selenium toner dilution : help with a math problem

Don_ih said:

so they mean the same thing.

Click to expand...

Yes, according to my father (chemical engineering PhD) 1+9 and 1:10 mean the same thing. 1+9 and 1:9 do not mean the same thing. I am a retired electrical engineer so I am personally staying out of it.

JerseyDoug said:

Yes, according to my father (chemical engineering PhD) 1+9 and 1:10 mean the same thing. 1+9 and 1:9 do not mean the same thing. I am a retired electrical engineer so I am personally staying out of it.

Click to expand...

In my experience, engineers believe two things:
1) the only valid way to understand something is the way that engineers understand it; and
2) most likely, you need to be an engineer to understand it anyways!
At times during my life, many of my best friends were engineers .
As far as the entomology issues, I think we could solve everything if we translated photographic chemical mixing instructions into Law French. That would accomplish a few things:
a) we would have no further disagreements about those instructions, because almost no one understands Law French, and of the very few who do understand it, they probably don't mix up chemicals anyways; and
b) amongst those who do understand Law French, very few understand how to pronounce it; and
c) amongst those very few who do understand how to pronounce it, they never get into disagreements with anyone other than those who get into disagreements about how Latin was historically pronounced, and how many of those are here on Photrio!

pentaxuser said:

Thanks Don So you say and write "I have a degree in math or a math degree"? Math sounds strange to me perhaps because we in the U.K. always say maths so it might be just "conditioning" but equally it seems to make sense because mathematics has always seemed to be a study of numbers plural or symbols plural where the collective and singular noun math does not seem to describe it as well

Maths rather than math seems logical and is not in the category of say the phrase like "non inflammable" which I admit has always been confusing or the name spelt as Majoribanks but pronounced Marshbanks Finally Cholmondeley pronouced Chumley takes us to the territory of a comic sketch that might have been made for a conversation between Jed Clampett and his English butler

pentaxuser

Click to expand...

I In my opinon ,math is a lot more logical than language. It always gets me when people order a dish "with no cheese" when they mean "without cheese".

If you really want to get it going warm the toner up to 30°C, be careful KRST will soften the gelatin, nice and plump.

I've got a BS in chemistry, took a bunch of awesome physics courses, calculus(s). All the rigor is unimportant except for keep good notes and repeat thyself! Temperature is a huge factor, as well as time and agitation.

For warmtone use a more dilute solution easy peasy. Probably easier to set up for your normal room temperature 21-22°C for me, although my darkroom can be a bit cooler.

I have a dedicated microwave (same one for the last 30+ years) I use it in very short doses for warming working solutions, and in longer times for warming pure water (to mix with room temperature water) to get to recommended mixing temperatures for XTOL, Bromophen etc. I use a variable speed, laboratory, shaft driven stainless propeller mixer for powders, what a wonderful thing that is.

Don't make it harder than it is.

RalphLambrecht said:

I In my opinon ,math is a lot more logical than language. It always gets me when people order a dish "with no cheese" when they mean "without cheese".

Click to expand...

I remember watching a nearly deaf colleague (decidedly American) trying to order a single dish of pasta, we were in Germany. He kept saying "One" in English and using his index finger instead of his thumb. Needless to say he got two plates of some very delicious pasta

It was classic, like a scene from a movie. A fellow customer interpreted part of the conversation, trying to quiet my colleague, but didn't get the quantity right.

MattKing said:

As far as the entomology issues …

Click to expand...

MattKing said:

those who get into disagreements about how Latin was historically pronounced, and how many of those are here on Photrio!

Click to expand...

I’m not saying anything, Matt! Stumm.

Latin entomology

Will we now construct an anthology of the epistemology of the etymology of entomology?

Okay, first the dilution question, just to stay on topic, but it's not only unnecessary to do all the figuring, but not good practice to try to stick to a particular dilution of toner. More later; here's the formula for figuring any dilution from any other:

Q1/Q2 :: C2/C1 or… Q1 x C1 = Q2 x C2

Where
Q1 = quantity 1, Q2 = Quantity 2, C1 = Concentration 1 (%), C2 = Concentration 2 (%)

This works for anything. I use it to dilute 100-proof vodka that's been infused with lemon peel to 32% to make limoncino too

To use your example:
You have 1 liter of toner 1+9 and want an unknown volume of toner 1+20.

So: first convert your dilutions to percentages:

A 1+9 dilution has 10 total parts, one part of which is toner, so that's 1/10 or 0.1 or 10%

A 1+20 dilution has 21 total parts, one of which is toner, so that's 1/21, or approx. 0.05 or 5% (I've rounded here to a 1+19 dilution, which is way close enough)

...So replace Q1, Q2, etc. with values. C2 is your unknown.

The equation then is: 1000 x 10 = X x 5 - or - 10,000 = 5x

Divide both sides by 5 and you get: 2000 = X

So to make your liter of 1+9 dilution a 1+19, just add water to get a total volume of 2 liters.

However, you don't need to know the exact dilution of your toner to get good results. In fact, using a specific dilution of toner for a specific time will not even give you consistent results. Why? Because every print your run through the toner weakens it a bit. After a few prints, you'll need to lengthen the toning time to get the same results.

The better way is to simply make up a toning solution at the dilution you think will work best and tone a print. Keep an untoned print close by for comparison and use good lighting. Pull the print when the tone change has almost reached what you want (the print will continue toning in the rinse for a short time).

Keep track of the time. If toning times are too long, you need a stronger dilution, if too short, you need weaker. How much stronger of weaker depends on the time. Add toner concentrate (in very small amounts) or water (in larger amounts) to find a dilution that works for your paper and the amount of toning you like.

After you tone, save your toner! Filter it and store it in a bottle. It will last for years. When you're ready to tone again, filter the toner (there will be a precipitate; it's harmless) and see how it tones. If times are too slow, add more toner concentrate to replenish the solution. I've got two jugs of toner, one labeled "weak" and one labeled "strong" that have been going for 10+ years each.

This method of replenishing and reusing toner is economical and keeps you from discarding toxic selenium down the drain. However, you'll never have an exact dilution; just a dilution that gives you the degree of toning you want in a reasonable time.

Best,

Doremus

People that don't know the difference between etymology and entomology really bug me!

As for Latin pronunciation; I spent a good deal of my graduate studies learning about the regional pronunciations of Latin for liturgical musical works. Verdi's Requiem text is pronounced differently in Italy than Mozart's Requiem text is in Germany and Austria. Spanish church Latin is different that English/American, etc., etc. All that's important for musicians and, maybe, priests

Best,

Doremus

snusmumriken said:

I’m not saying anything, Matt! Stumm.

Click to expand...

Don_ih said:

View attachment 394441 Latin entomology

Click to expand...

I blame those too many reads of Lord of the Rings - particularly the parts about the Ents - during my youth.
Come to think of it, at least some of those reads coincided with the aforementioned dalliance with University Physics.

MattKing said:

the parts about the Ents

Click to expand...

I was going to reference Ents but thought enough odd things had already been introduced.

mshchem said:

I remember watching a nearly deaf colleague (decidedly American) trying to order a single dish of pasta, we were in Germany. He kept saying "One" in English and using his index finger instead of his thumb. Needless to say he got two plates of some very delicious pasta

It was classic, like a scene from a movie. A fellow customer interpreted part of the conversation, trying to quiet my colleague, but didn't get the quantity right.

Click to expand...

If he had been asking for a dry Martini, he’d have got three.

Start with 10ml of concentrate add water to 100mL test

If you want to test stronger, to the solution above add 40ml of concentrate dilute to 200ml

As noted the stuff lasts forever. I have Kodak rapid selenium toner in the original brown glass bottle, probably 60 years old, works fine. (Of course I keep this in my toner cellar )

Doremus Scudder said:

After you tone, save your toner! Filter it and store it in a bottle. It will last for years. When you're ready to tone again, filter the toner (there will be a precipitate; it's harmless) and see how it tones. If times are too slow, add more toner concentrate to replenish the solution. I've got two jugs of toner, one labeled "weak" and one labeled "strong" that have been going for 10+ years each.

This method of replenishing and reusing toner is economical and keeps you from discarding toxic selenium down the drain. However, you'll never have an exact dilution; just a dilution that gives you the degree of toning you want in a reasonable time.

Click to expand...

Did not know it could last this long used this way. Thanks.

It's really a lot easier to understand this if you think of working solutions / dilutions in the "1+X" way, not the "1:X" way.

So for example suppose we want to make 1 liter of a 1+9 dilution. We take 100 ml of stock, add 900 ml of water, and have 1000 ml of 1+9 working solution.

Now we decide, oops, we need 1+19. You already have the 1 unit of stock (100 ml) in 1+9 solution, so you just need to add 10 units of water. So take your 1000 ml of 1+9, add 1000 ml of water, and now you have 2000 ml of 1+19 solution.

Hopefully it's apparent that the difference between 1+19 solution and 1+18 or 1+20 is not going to be easy to see in most photographic processes, so sweating extreme precision is not necessary.