PC-TEA vs MYTOL for HP5+/Tri-X in 135/120 format

gainer · Apr 29, 2008

The biggest trouble with dissolving stuff in TEA IMO is its viscosity and the resulting low level of Brownian motion. Viscosity of TEA decreases with increased temperature. Try putting the TEA and ascorbic acid in a pyrex or stainless steel double boiler covered with Glad or other heat-safe plastic wrap with water in the bottom container. TEA boils at a very much higher temperature than water. It will discolor at temperatures higher than about twice the boiling point of water, but you won't get that high with a double boiler. You will hear steam escaping from the lower container before the upper container gets more than a few degrees hotter than boiling water.

hka · Apr 29, 2008

Tom Hoskinson said:
Harry, in my experience, AA (by itself) dissolves readily in TEA at TEA temperatures between 27°C and 49°C. Sodium sulfite could slow dissolution.

Gotta go - more later.

Tom,
Thanks but I've not used Sodium Sulfite sofar.

Gainer,
Also thanks. I know what you mean by that and I will give it a try by making a new badge.

Tom Hoskinson · Apr 29, 2008

Tom Hoskinson said:
Harry, in my experience, AA (by itself) dissolves readily in TEA at TEA temperatures between 27°C and 49°C. Sodium sulfite could slow dissolution.

Gotta go - more later.

Did you add the sodium sulfite to the mixture?

Is the Ascorbic Acid Pure Food Grade Ascorbic Acid? (if was pure AA, it should readily dissove in warm TEA).

You could try Pat Gainer's procedure to convert the AA into Ascorbate:

To the mixture of AA and TEA add a few ml (5 to 8 ml) of distilled or deionized water. With stirring, everything should now dissolve into a slurry.

This slurry should be soluble in TEA and in Propylene Glycol (or water).

Alan Johnson · Apr 29, 2008

hka
cas 134 03 2 is sodium ascorbate not ascorbic acid,that's why it wont dissolve.

Jordan · Apr 29, 2008

hka --

I visit APUG often but not necessarily every day. You could have e-mailed me through my website and I would have gotten back to you very quickly!

Anyway, I have two comments:

1. If you did indeed use sodium ascorbate instead of ascorbic acid, all bets are off. One of the reasons I came up with the Instant MYTOL formula was to avoid having to use sodium ascorbate, which is more difficult to get and more prone to degradation. Sodium ascorbate will probably be less soluble (there is nothing there to solvate the sodium ions) and the pH of the developer will be way too alkaline.

2. Did you try adding a couple of mL of water, as directed on my original recipe page (http://www.photosensitive.ca/wp/easy-film-developers) ? The water helps solubilize the ascorbic acid but doesn't appear to impact the storage life of the concentrate at all. My last batch of Instant MYTOL in propylene glycol / TEA lasted 1.5 years with no major changes in activity.

hka · Apr 30, 2008

Alan Johnson said:
hka
cas 134 03 2 is sodium ascorbate not ascorbic acid,that's why it wont dissolve.

Allen,
That's a good point. I looked again at the bottle and I thougt it was the right stuff but the description on the label tells me L-Ascorbic acid sodium salt, 99% - C6 H7 Na06.
Is this than the right ascorbic: L(+)-Ascorbic acid; Vitamin C; C6 H8 O6;
CAS# 50-81-7.
Thanks for your help.

hka · Apr 30, 2008

Tom Hoskinson said:
Did you add the sodium sulfite to the mixture?

No I didn't because the recipe tells me that I have to add the sodium sulfite when making the working solution.

Is the Ascorbic Acid Pure Food Grade Ascorbic Acid? (if was pure AA, it should readily dissove in warm TEA).

The problem was that I used the wrong kind of Ascorbic Acid the Sodium Salt.:confused:

You could try Pat Gainer's procedure to convert the AA into Ascorbate:

Maybe the problem is solved when I use the proper Vitamin C.

To the mixture of AA and TEA add a few ml (5 to 8 ml) of distilled or deionized water. With stirring, everything should now dissolve into a slurry.

This slurry should be soluble in TEA and in Propylene Glycol (or water).

Yeah I added a few ml of deionized water.

Thanks again Tom for spending your time.

hka · Apr 30, 2008

Jordan said:
hka --

I visit APUG often but not necessarily every day. You could have e-mailed me through my website and I would have gotten back to you very quickly!

Anyway, I have two comments:

1. If you did indeed use sodium ascorbate instead of ascorbic acid, all bets are off. One of the reasons I came up with the Instant MYTOL formula was to avoid having to use sodium ascorbate, which is more difficult to get and more prone to degradation. Sodium ascorbate will probably be less soluble (there is nothing there to solvate the sodium ions) and the pH of the developer will be way too alkaline.

2. Did you try adding a couple of mL of water, as directed on my original recipe page (http://www.photosensitive.ca/wp/easy-film-developers) ? The water helps solubilize the ascorbic acid but doesn't appear to impact the storage life of the concentrate at all. My last batch of Instant MYTOL in propylene glycol / TEA lasted 1.5 years with no major changes in activity.

Jordan,
ad 1. Yes I used the wrong type of Vit. C.,
ad 2. Yes I added some ml water.
I didn't know that I good reach you directly bij mail. I hope the problems are over when using the right stuff, otherwise I know now where to find you.
Thanks.

vieri · May 27, 2008

Hello, I have a question for the collective wisdom: I am thinking that adding some Sodium Sulfite to PC-TEA will give finer grain, and I thought that adding 8 gr per 100 ml (or 80 gr per liter) would be a good starting point for experimenting. Here are the questions:

- Would this work as I think, and if so is the amount of Sodium Sulfite ok?
- When do you guys think it will be best to add the Sodium Sulfite, I would imagine after adding the Ascorbic Acid and before the Phenidone?

Thanks in advance!

vieri · May 27, 2008

Another idea: making a sodium sulfite solution "on the side" and add it to the working solution. In this case, again, would my 8% dilution of the sulfite solution work, and what you think the ratio should be against the developer? For instance, instead of using PC-TEA 1:50 with water, I am thinking maybe adding the PC-TEA 1:50 either directly to the 8% sulfite solution or to a lesser solution... oh well. Maybe adding KB wouldn't even provide grain benefit after all

strangepics · May 27, 2008

"PC TEA will give very crisp edges and a little more grain"

Although some people reported edge softening as well, presumably because TEA contains some DEA, and DEA is a strong silver solvent. Bummer.

That said, I like PC-TEA better than Xtol for all the reasons mentioned, and I like the grain I get with it - either softened or whatever.

Alan Johnson · May 28, 2008

vieri,

Here is the approximate pH of some solutions:
Xtol/Mytol-about 8 , PC-TEA 1:100- about 9 , Sodium Sulfite 100g/L-about 9.7.
If sodium sulfite alone is added to PC-TEA it increases the pH and in my test the grain too.To do some research it would be more interesting IMO to add , in addition to sodium sulfite, some sodium bisufite or boric acid to take the pH closer to that of Mytol and see if there is an improvement in PC-TEA grain.
(there was a url link here which no longer exists)

vieri · Jun 3, 2008

Alan Johnson said:
vieri,

Here is the approximate pH of some solutions:
Xtol/Mytol-about 8 , PC-TEA 1:100- about 9 , Sodium Sulfite 100g/L-about 9.7.
If sodium sulfite alone is added to PC-TEA it increases the pH and in my test the grain too.To do some research it would be more interesting IMO to add , in addition to sodium sulfite, some sodium bisufite or boric acid to take the pH closer to that of Mytol and see if there is an improvement in PC-TEA grain.
(there was a url link here which no longer exists)

Alan,

thank you for your reply - makes sense, I will try and find some boric acid to add to the mix. Any suggestion re: proportions of sodium sulfite & boric acid?

Alan Johnson · Jun 3, 2008

Note that Ryuji wrote "..solvent does not imply finer grain.." so this is research not a promise of success. The sodium sulfite,bisulfite or boric acid do not dissolve in TEA, have to be made up separately in water, your on the side method with 80g/L sulfite would be interesting.
I used pH paper and added the bisulfite bit by bit to get pH 8. It could be done with boric acid, at a guess a few grams per liter. Without the pH paper it would take more tests.Development times may be rather long,probably best to use the 1:50 dilution.But it would be your research,your rules.

Jordan · Jun 4, 2008

A while ago, I did some experiments that involved using the PC-TEA or PC-Glycol stock solutions in combination with sodium sulfite or metabisulfite. The combinations were meant to have comparable pH and phenidone concentrations to XTOL. I called them "PC-Gly-TOL" and "PC-TEA-TOL" and they were once in the recipes section of this site, but when APUG got renovated, they were removed.

I developed a lot of film with them and it worked well. I can post links to samples, if needed. I now use Instant MYTOL for the same purpose.

I don't have my own notes handy, but a quick Google came up with a 75 ml PC-TEA stock and 31 g sodium metabisulfite in 1 L water to approximate stock XTOL. You can halve the metabisulfite and PC-TEA stock to approximate 1+1 XTOL. You may have to fiddle with development times a bit, but using XTOL times to start should work pretty well.

gainer · Jun 4, 2008

I'm guessing too, but it seems to me that if you want sulfite along with PC, you could dissolve the P and the C in propylene glycol with just enough TEA to neutralize the ascorbic acid and use a sodium sulfite solution instead of plain water. This would be a "kissing cousin" of D-23, I think.

Paul Verizzo · Jun 4, 2008

pnance said:
There is no 100% alcohol. It always has water in it,

I presume you mean alcohol available for mere mortals at the corner drug or liquor store. Like isopropyl and denatured ethanol or Ever Clear. There are lab grade purities, although that would be a bit of overkill for developers.

I think methyl alcohol/shellac thinner/wood alcohol/stove fuel can be 100%. It's not a distilled product.

gainer · Jun 4, 2008

Paul Verizzo said:
I presume you mean alcohol available for mere mortals at the corner drug or liquor store. Like isopropyl and denatured ethanol or Ever Clear. There are lab grade purities, although that would be a bit of overkill for developers.

I think methyl alcohol/shellac thinner/wood alcohol/stove fuel can be 100%. It's not a distilled product.

Methyl alcohol is also called wood alcohol because it is one of the products of destructive distillation of wood. It is part of the pyroligneous liquor. The professor of the freshman chemistry class told us that if we couldn't remember "pyroligneous liquor" on the exam, he would give credit for "goo that comes off of burnt wood", so, of course, I have remembered the proper term all these 60 years.

Alcohol has water in it mostly because it has an affinity for water. The water can be removed by anhydrous copper sulfate which can be obtained by heating common copper sulfate until the crystals turn white. If there is water in your alcohol the crystals will turn blue. If you open the container enough times the crystals will eventually turn blue.

Paul Verizzo · Jun 4, 2008

gainer said:
Methyl alcohol is also called wood alcohol because it is one of the products of destructive distillation of wood. It is part of the pyroligneous liquor. The professor of the freshman chemistry class told us that if we couldn't remember "pyroligneous liquor" on the exam, he would give credit for "goo that comes off of burnt wood", so, of course, I have remembered the proper term all these 60 years.

Alcohol has water in it mostly because it has an affinity for water. The water can be removed by anhydrous copper sulfate which can be obtained by heating common copper sulfate until the crystals turn white. If there is water in your alcohol the crystals will turn blue. If you open the container enough times the crystals will eventually turn blue.

Back in 7th grade I did a school science fair project on wood distillation! I heated wood in a test tube and then dripped the distillate off. No particular product.

I thought methanol was made mostly from coal nowadays, but Wikipedia says that coal has been superceded by natural gas: http://en.wikipedia.org/wiki/Methanol

Aurum · Jun 4, 2008

Its difficult to get drier than 96% alcohol (Ethanol) as it forms an azeotrope with water. This is a chemical term that means when you distil the alcohol, it doesn't come off as a pure chemical, it comes off as a constant boiling mixture of alcohol and water
Wikipedia definition

To get 100% dry ethanol, you have to use a chemical like Calcium chloride, or a material like zeolite to suck every last bit of water out of it. Its expensive, and 100% dry ethanol will quickly absorb water from the air if its not sealed in an airtight container

hka · Jun 18, 2008

Today I recieved the right chemical (Ascorbic Acid) to make a new badge of Mytol. As you have read my first badge would'nt dissolve. After some good advise, given earlier in this thead, the problem lies in de "wrong" type of Vitamin C.
I used the Sodium Salt instead of the Ascorbic Acid.
The new stock solution is mixed cleary and all the solids have dissolved now without any problem.
I just did a kind of "cliptest" and added some water with Sodium Sulfite to the stock solution and discoverd that there is activity in the solvent.
I'am glad to let you know this because you helped me realy to solve the problems.
The next step is to develop a film in it, that will be after the weekend.

Thanks to you all...

Jordan · Jun 23, 2008

Let us know how it works out!

hka · Jun 25, 2008

My first tests with Instant Mytol are succesfull.
I developped a piece of film (HP5+ @ 400 ISO) with Zone II, V and VII exposures and find out that 11:00 min. is sufficient to reach the right density-values. I did this in rotary on a CPP2 with 50 rpm, 20ºC, 1+1.
So, that's very promissing and I'am looking forward making some outdoor shots this weekend.
After printing them the evaluation can take place if this the one I'am looking for.

Question:
Is there any possibility to make also a stock solution from the Sodium Sulfite.
I can imagine to dissolve the 30g Sodium Sulfite in 1L water and use about 250ml at the time and adding part A to develop a film.
What's the self-life of this Sodium Sulfite stock-solution?

Jordan · Jul 1, 2008

Glad to hear the Instant Mytol is working, I always feel better when people other than me are able to get good results with it

I'll let others answer in detail about sodium sulfite as a stock solution, but I think that unbuffered sodium sulfite solutions don't have a great shelf life -- unfortunately.

Cor · Aug 5, 2010

Rather than starting a new thread, I attach to this old thread: and would like to know if there is a way to make a stable 30gr/l Sodium Sulphite (or higher concentration) that won't turn slowly in a sulphate solution.

It would be very convenient if you have a stock solution of InstantMytol in Glycol, a (concentrated) solution of sulphite and some water to mix (just like the different Pyro formulea)

Best,

Cor

PC-TEA vs MYTOL for HP5+/Tri-X in 135/120 format

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