My Borax Project
Borax is useful in many ways. Some of us worry about the purity of the commonly and cheaply available 20 Mule Team Borax. There is another concern in cases where accuracy of weight is important. Borax has 2 possible states of hydration, decahydrate and pentahydrate. If a 100 gram sample of pure borax has pentahydrate and decahydrate mixed, the assay will show a greater weight than 100 grams. If 5 grams of a 100 gram sample are the pentahydrate and the rest the decahydrate,...
Gainer;
Glad to see that the article finally made it into the articles section. Could you do us a favor and show us all of the prints with the same amount of filtration? There is no way to tell the difference between the prints in a meaningful way if you give us different prints. It's like doing a study on plant growth and trimming one plant more than the others, a bad practice in scientific testing.
Ben
Gainer,
Nice piece of work. There are a lot of theoretical objections to practical matters voiced in this forum, but in the mantra of the experimentalist, "if it happens, it must be possible".
Would you consider examining non-photographic sodium carbonate and bicarbonate in a similar fashion? I'm pretty sure that the hot-tub and kitchen grades are rather pure; it has been stated (with authority but not necessarily accuracy) that anything but reagent grade contains chloride and is unsuitable for photography. Since I don't make up my own developers that often, I don't have a dog in the fight, but I've always wondered what the facts of the matter were.
There is certainly a version of D-76 that uses 8 g/l each of borax and boric acid as a buffer. What I tested here was similar, but 2.5 times as strong. With borates, the buffering capacity may be cranked up a lot more than the pH by such combinations. The pH certainly did not rise with my 20-20 combination over that with plain borax, but may have been stabilized.It is my understanding that Eastman long recommended up to (something like) eight or ten times the normal level borax for D76 in certain applications.
There is certainly a version of D-76 that uses 8 g/l each of borax and boric acid as a buffer.
The heavily buffered version is D76d.
You might want to look at the Wellington Borax MQ formula that is said to be the developer D76 is derived from. It;s a clean working, long lasting relatively fine grain developer according to the Pritish Journal of Photography.
Wellington Borax MQ Film Developer
Metol 2.3g
Hydroquinone 2.3g
Sodium Sulphite (cryst) 23g
Borax 23g
Water to 1 litre
Wellington & Ward were a British manufacturer of film, plates, papers etc who were bought by Ilford in the late 1930's.
Ian
Very interesting. I shall have to try it. Is there a British measure of weight that makes the weights come out 1, 10, 10 and water to 1 quart or gallon?
PS: Reminds me of the old bawdy joke about the marriage between the circus midget and the lady giant:"Nose to nose his toes were in it and toes to toes, his nose was in it." That's about how it would be with highlights and shadows of that negative without very low contrast paper. No joy.
interesting....I cannot pretend to comprehend all of this, but it is very interesting.
I'm unclear about one thing though, if the increased contrast is expected (at least partially) due to the solution's greatly increased buffering capacity, would we not also expect increased contrast in the solution with both borax and boric acid? That is to say, wouldn't the solution with the excess borax and boric acid also have much greater buffering capacity than the nominal...and therefore also exhibit less (localized?) compensating effect?
Clearly, it is complex.
Very interesting. I shall have to try it. Is there a British measure of weight that makes the weights come out 1, 10, 10 and water to 1 quart or gallon?
It is also 1:1:10:10:2000 if one assumes an Imperial gallon is 4.6l - in fact 4.546 litres.
Murray
Somethings wrong with your maths Murray
2.3:2.3:23:23:1000 works out as 1:1:10:10:434.78
Ian
Yes the formula is published in metric & Imperial so it was 10grains/100grains/10oz. Interestingly the ratio of M:Q and quantity is very similar to D76b.
Ian
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