D-76/ID11 pH change?

[Arvee]

Is the pH change over time associated with D-76 a characteristic of past formulations? Is the current offering free of this problem?

Is ID-11 also susceptible to a rise in pH over time?

Thanks in advance!

-Fred

 

[Photo Engineer]

Is the pH change over time associated with D-76 a characteristic of past formulations? Is the current offering free of this problem?

Is ID-11 also susceptible to a rise in pH over time?

Thanks in advance!

-Fred

All HQ containing developers have a small pH shift in the first few hours of mixing. The pH goes up then down due to oxidation of HQ, formation of the sulfonate salt of the quinone, and release of Sodium Hydroxide.

There are more detailed and extensive threads on this elsewhere on APUG.

PE

 

[Arvee]

There are more detailed and extensive threads on this elsewhere on APUG.

PE

PE, I did several searches and came up empty. Care to suggest key words? And, has Kodak fixed the problem that has been mentioned in the past? Is it the borax/boric acid fix?

Thanks!

-Fred

 

[Anscojohn]

My understanding is that the "troublesome" Ph changes come when D-76 is replenished. Is that correct?

 

[Ian Grant]

Try looking for replenishment, as Anscojohn mentions.

The problems with ID-11/D76 are usually associated with deep tank use & replenishment and the length of time before you start using an entirely fresh batch.

Ian

 

[Anscojohn]

.

The problems with ID-11/D76 are usually associated with deep tank use & replenishment and the length of time before you start using an entirely fresh batch.

Ian[/QUOTE]
*******
One of the olde lab rats with whom I worked as a youngster--a real good ol' boy-- informed me that "76 teks a wahl 'fore hit gits gooooood."

 

[Photo Engineer]

Well, first off, the problem has not been solved. So, it teks a wahl 'fore hit gits gooooooood!.

Ah lets it sit for 'bout a day fellers.

PE

 

[Ian Grant]

.
*******
One of the olde lab rats with whom I worked as a youngster--a real good ol' boy-- informed me that "76 teks a wahl 'fore hit gits gooooood."

Yes that's true and the same goes for Microphen & Xtol. But what you do when making up a fresh tank is season it with some from the old. That really helps.

Once mature ID-11/D76, Adox Borax MQ, Microphen, ID-68 and countless other similar type developers start to outperform the same developer - fresh.

I've always used these developers with replenishment, and you don't need a pH meter to tell you when it's on the turn & about to collapse, it's second nature.

Ian

 

[Arvee]

So if the MQ formulations are all susceptible to pH fluctuations (I happen to prefer replenished systems), what are the 'other' solutions? Replenished D-23? I would really like to settle on a stable, consistent platform.

BTW, all, thanks for the input. There is a wealth of experience on this board!

-Fred

 

[Ian Grant]

Unless you're putting many hundreds of films through an ID-11/D76 deep tank system you won't come across a problem. Even Replenished D23 or D25 will collapse over time, pH is only one of the symptoms.

Ian

 

[Arvee]

Thanks, Ian, I am looking for a system where I can process approximately 25 rolls/month with a developer/replenisher that will be consistent over a 90 day period.
I have presently been using Tmax RS and I turn it fairly quickly, about 40 rolls per container/gal. I thought replenished D-76 might be a good backup/alternative and that is what we used in school but that was before I knew about and became concerned with the pH problem.

I think I read somewhere that John Sexton pitches any D-76 that is six weeks old, or maybe it was 30 days old. That prompted this query.

-Fred

 

[Ian Grant]

Well I certainly get that with Xtol, and used to with ID-11. I'm not sure that Sexton would be replenishing, he's sponsored by Kodak so he can afford to be very overly cautious.

Ian

 

[Arvee]

I'm not sure that Sexton would be replenishing, he's sponsored by Kodak so he can afford to be very overly cautious.

Ian

Good point!

-Fred

 

[MikeSeb]

Another approach would be to mix D76H yourself from bulk chemicals. This variant of D76 uses 2.5 grams metol per liter, rather than 2.0; and omits the HQ entirely. Contains anhydrous sodium sulfite 100g and borax 2 g. I find it nearly indistinguishable from factory D76.

By omitting HQ the pH/activity change is eliminated.

 

[Paul Verizzo]

Another approach would be to mix D76H yourself from bulk chemicals. This variant of D76 uses 2.5 grams metol per liter, rather than 2.0; and omits the HQ entirely. Contains anhydrous sodium sulfite 100g and borax 2 g. I find it nearly indistinguishable from factory D76.

By omitting HQ the pH/activity change is eliminated.

That's D-23 at 1/3rd the Metol. Unless you have some experience otherwise, it sounds rather strange. Might work with, oh, half hour development times. There's a reason the HQ is there, superadditivity.

 

[Arvee]

Actually, D76H, developed by Grant Haist at Kodak, works at very nearly the same times as D76. A & T consider D76H to be their standard against which they compared many other developers in their book, The Film Developing Cookbook. It's only drawback is that it is a 'mix from scratch' proposition.

-Fred

 

[Paul Verizzo]

Help me through this...

Actually, D76H, developed by Grant Haist at Kodak, works at very nearly the same times as D76. A & T consider D76H to be their standard against which they compared many other developers in their book, The Film Developing Cookbook. It's only drawback is that it is a 'mix from scratch' proposition.

-Fred

Two developers. One has 2.5 grams Metol, the other has 7.5. The latter develops film in 12 minutes, the former in 5-9? That the extra .5 gram of Metol in 76H makes up for 5 grams of HQ?

Completely illogical.

 

[Photo Engineer]

D76 has 2 g Metol and 5 g HQ. D76H has 2.5 g Metol. At the low pH of this developer, the bulk of the activity comes from the Metol, and it has reduced swing in pH. Grant felt it was pretty effective.

PE

 

[Anscojohn]

Pardon my ignorance; but why all the hoopla about D-76 and pH? Were D76 at all a problem, I do not see why it should have remained such a "standard" since, what was it, 1927? Are there just people out they-ya what likes to complexify the (relatively) simple?

 

[Paul Verizzo]

D76 has 2 g Metol and 5 g HQ. D76H has 2.5 g Metol. At the low pH of this developer, the bulk of the activity comes from the Metol, and it has reduced swing in pH. Grant felt it was pretty effective.

PE

I know the HQ by itself is pretty ineffective, but it is a major kicker for the Metol. If it wasn't it wouldn't be there, a la D-23.

Still doesn't make sense how less developing agent give more development speed with all else the same.

 

[Photo Engineer]

Paul;

I would have to ask Grant. Next time I see him, probably near the end of October, we can talk about it.

John;

D-76 is kind of an industry standard. Kodak used to use it for all release testing of B&W products.

PE

 

[Anscojohn]

[
D-76 is kind of an industry standard. Kodak used to use it for all release testing of B&W products.

PE[/QUOTE]

So I have long been led to understand. So, is not this thread much ado about nothing?

 

[gainer]

"I know the HQ by itself is pretty ineffective, but it is a major kicker for the Metol. If it wasn't it wouldn't be there, a la D-23. "

Hydroquinone has NO effect on Metol unless sulfite is present. Sulfite and ascorbate each have marked effect in combination with Metol. If you want longer life from a Metol developer, use it with sodium ascorbate, with or without suldite. The ascorbate increases the activity of Metol by replenishing, while the sulfite removes the reduction products, but allows the amount of useful Metol to diminish. This is not my theory. I found it along with demonstrative graphs in "The Theory of the Photographic Process." If you are going to use sulfite anyway, you may as well use the hydroquinone, but ascorbate may turn out to be cheaper. It may be that the combination of ascorbate and sulfite does not do what we think it should if the sulfite changes the products of reaction before the ascorbate can regenerate them.

I had a teacher in aerodynamics once who said, in effect, "I don't pretend to know everything. I really do." He said it with tongue in cheek, of course. I don't claim to know anything I haven't read, or even most of what I have read, but at least it's worth a practical test.

 

[dancqu]

Two developers. One has 2.5 grams Metol, the other has 7.5.
The latter develops film in 12 minutes, the former in 5-9?
That the extra .5 gram of Metol in 76H makes up
for 5 grams of HQ? Completely illogical.

D-76H, a 1/3 strength D-23. That 2 grams of borax is a left
over from the 1920s formula for D-76. Although 10 times as
much borax is reputed to shorten developing times with D-76
it's use in the H version serves no function in the absence of
hydroquinone.

From some little reading of the similarity of results twixt
D-23 and D-76 I've concluded that D-76 is the low cost
D-23. Hydroqinone is about 1/2 the price of metol. D-76
works but does have that little ph problem. Dan

 

[gainer]

I suppose borax improves the buffering. It could be left out for a test. There is also DK-76 to be considered.