Quote:[Patrick; Any biochemistry text will draw chemical reactions with circular arrows for each reactant. Things keep cycling each other. With an ET developer, it can either recycle both ingredients or have one 'pump' the other in activity.]
I have known since high school that if it is possible for the ingredients of a solution to form more than one set of compounds, they will be formed given the right conditions. Of course, if you want a particular set of compounds to be formed you have to know the conditions. I make prety good coffee because I know the right conditions to avoid the "fusel oils". Whether or not that is what they really are, I don't know
I have found that the activity of the p-aminophenol-ascorbate developer is not greatly diminished by using 0.01 moles of p-aminophenol, 0.05 moles of ascorbic acid and 0.06 moles of sodium hydroxide plus 10 grams of borax. The borax and sodium hydroxide may be replaced by 16.7 grams of sodium metaborate. Thus the recipe becomes:
ascorbic acid................8.8 grams
2.4 grams sodium hydroxide + 10 grams borax
sodium metaborate........16.7 grams
Water to 1 liter.
FP4+ for 8 minutes at 70 F will still be sufficient for most purposes.
I forgot to say that the above recipe is for the working strength solution.
Still the best and easiest to mix is the phenidone-ascorbate in water. Phenidone is less sensitive to bromide content than just about anything other than (perhaps) amidol. That means that it will make a long lived developer in a self replenishing system. The aerial oxidation in such a solution is to the ascorbate and its product is acidic, but the acidity is minimized by the buffering action of the borax. A liter of working strength, reusable developer can be made from 0.8 grams of phenidone, 10 grams of sodium ascorbate and 10 grams of borax. Note that the phenidone is at half the strength of the original formula.
If it is easier, you may use 8.8 grams of ascorbic acid + 4.2 grams of sodium bicarbonate. Mix it in a little warm water and let the effervescence subside befor adding the phenidone and borax.
Don't even bother with the bicarb. 0.8 grams phenidone, 9 grams ascorbic acid, 25 grams borax and water to make a liter will do the job for either film or paper. If you keep your phenidone in a glycol solution, you can mix a batch in just a few minutes. You will probably want to dilute the stock for use. I'll come back when I can give more information.
FP4+, 6 minutes, 70 F; 7 miuntes, 68 F. Normal contrast, no problem with box speed + or - 1/2 stop.
Sorry, I didn't do exactly this, but I did do two things that proved to my satisfaction that my MC-TEA only needs more alkali to activate it, and that sulfite doesn't have any particular role in getting the metol-ascorbic acid synergy going.
Originally Posted by gainer
Instead of adding two teaspoons of sulfite to a liter of working solution I added two tsp sodium metaborate. The resulting developer was extremely active, developing Delta 400 to a contrast index of 1.9 in the same time it takes the sulfite mixture to get to 1.2. However, shadow detail was very poor, so I'll stick with the sulfite formula for now (especially since I have 5 lbs of the stuff).
I also tried using double the amount of sulfite (but no metaborate), which gave me about the same development time as the original amount.
If you should want to use acetaminophen (Tylenol) in place of p-aminophenol, the 5.45 grams of p-aminophenol will be supplied by 7.5 grams of acetaminophen or 15 of the 500 mg tablets. If you use the tablets, crush them to a powder. Add 1/2 teaspoon of ascorbic acid and 1/4 tsp of sodium bicarbonate to 40 ml water, let the effervescence subside and then add the acetaminophen and 4 grams of NaOH or 5.6 grams of KOH. Stir well and let it stand a while. Bring the water up to about 700 ml and add 2 teaspoons of ascorbic acid and 2 tablespoons of borax. Add water to make a liter.
You will probably have to dilute this developer at least 1+4 to make it managable. The best way to dilute these developers is to add more of the ascorbic acid-borax mixture. You can make 4 liters of it with 35 grams of ascorbic acid and 100 grams of borax. This way you need not worry about whether you will have enough of the developing agent in the working solution when you try such outrageous things as stand development for an hour with 1:50 dilution of the working solution. There will be as much of the ascorbate in the diluted solution as in the full strength, and that will ensure that the p-aminophenol or phenidone is continually regenerated. This is a chance to see if the usual statements about starved development and characteristic curves, Mackie lines, etc. are pertinent here.
Found another source of borax. Had only been able to find 20 Mule Team, and at last one source of that.
Pool supply stores have been referenced for hypo/fixer but hard to confirm actual product contents per some readers.
Here's one borax source:
NOT "Supreme Plus" - that has additional components, boric acid and fragrance. Still costs more than 20 Mule Team - strange that this is the case.
While I'm here, the same company has a sodium thiosulfate 'ChlorOut' product.
Haviland Chlor Out - I found MSDS(to confirm contents) the other day with alot of searching, but not tonight. Their web page will let you bring up Chlor Out for shopping basket but no MSDS - can't verify it's a current product. Lots of discounted 2# bottles on eBay, however.