[pure-silver] D-76 and variations


----- Original Message ----- From: "BertS" <aasainz@xxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Monday, November 28, 2005 4:12 AM
Subject: [pure-silver] Re: Buyer found for AGFA Photo


Richard Knoppow wrote:

----- Original Message ----- From: "Charlie Thorsten" <charlie_thorsten@xxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Sunday, November 27, 2005 3:00 PM
Subject: [pure-silver] Re: Buyer found for AGFA Photo


Snipping here.....
Te difference between buffered and unbuffered d76 is only a little bit of boric acid, isn't it? (my books are still in Wilma-proof boxes). If so, isn't it possible to make ID11 into a buffered D76 by adding a pinch of boric acid on mixing?

Boric acid is available even from grocery stores for those who don't stock raw chemicals.

Bert


The original D-76 formula and Ilford's published formula for ID-11 are:

Water (at 125F or 52C)                750.0 ml
Metol                                   2.0 grams
Sodium Sulfite, dessicated            100.0 grams
Hydroquinone                            5.0 grams
Borax, granulated                       2.0 grams
Water to make                           1.0 liter


The formula for D-76d, the buffered variety is:

Water (at 125F or 52C)                    750.0 ml
Metol                                       2.0 grams
Sodium Sulfite, dessicated                100.0 grams
Hydroquinone                                5.0 grams
Borax, granulated                           8.0 grams
Boric acid, crystalline                     8.0 grams
Water to make                               1.0 liter

With this amount of Borax and Boric acid the activity of the buffered developer is the same as that of freshly made D-76. The activity stays stable over long periods of time.
The activity of the buffered developer can be varied by changing the ratio of the Borax to Boric acid, the total of the two remaining the same.
It is probable that the packaged forms of both D-76 and ID-11 are slightly different. Probably both contain sequestering agents and possibly other stuff that is present in too small an amount to show up on the MSDS.

In the USA 20 Mule Team Borax is chemically pure enough for photographic use according to its manufacturer. However, be careful not to get "Borax Cleaner" which contains soap and other ingredients. Boric Acid is sold in many drugstores. People used to soak their feet in it.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx 

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