Patrick;
The Metol equivalent of Rodinal that you were working on is very similar, if not identical to Kodak HDD, a developer sold many years ago. It was quite stable.
PE
Ian;
Kodak HDD is not the "opposite" of Patrick's formula, it is an analog of his formula.
PE
Metol is said to be sensitive to hydrolysis in alkaline media:
http://books.google.co.uk/books?q=metol+hydrolysis+karlheinz+keller&btnG=Search+Books
That is not immediately obvious looking at the structure, and the odor on decomposition indicates some rather exotic chemistry.
I seem to remember seeing an acorbate form of Metol, using, I guess. ascorbic acid in place of sulfuric acid on its tail.
I don't like the idea of using KOH, mostly because it's hard to tell what I'm getting when I weigh it because it turns into a puddle while I weigh it.
The importance of Rpdinal is the very long shelf life etc.
I thought it was the result of the development that was important...
If I may be allowed to brag a little, PC-TEA is no slouch in that regard. I have not, for some reason, ever made a direct comparison with anything but Acutol, and that was a few years ago.Of course
It's the simplicity of Rodinal combined with the quality of the negatives produced that lead people like Patrick in search of similar developers using different developing agents.
But in a 100+ years it's been copied by many other companies, including Ilford & Kodak but no-one has yet come up with a simple alternative using other developing agents, that keeps well as a single solution concentrate.
This is why Rodinal is so remarkable.
Ian
If I may be allowed to brag a little, PC-TEA is no slouch in that regard. I have not, for some reason, ever made a direct comparison with anything but Acutol, and that was a few years ago.
Ian;
I think HC-110 is rather good as a developer and has good shelf life. I think that some of the higher dilutions of HC-110 have not been fully exploited and may prove to approach Rodinal. I also believe that a Metol based Rodinal, if stable, would be superior to Rodinal.
PE
You can titrate it with a standard acid. You can make a standard acid by titrating that with a standardized base. Or, you can use potassium acid phthalate (KHP, or potassium hudrogen phthalate) which is a common standard acid and titrate the KOH solution directly with the KHP solid. Use phenolphthalein as the indicator.
That's what all the hip lab cats do, man.
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