Paul Verizzo
Member
Hi, I'm back. Took a long break and here I am again.
I've decided to go with a lot of flow and look into ascorbic acid developers. Seems to have the results I've been looking for down other, less productive roads. I've not tried Xtol because of the 5 liter thing, times dilution, just unappealing.
Closer to my interest is the PC-Glycol and PC TEA work started by Patrick Gainer. Especially the former so that I could twiddle with accelerators. I'd not bought either glycol or TEA because I wasn't sure I wanted to spend the money (especially for shipping liquid).
So I recently checked out my Prestone Extended Life Anti-Freeze. Whaddya know, the chemicals I recall being in there decades ago are gone: "Silicate, phosphate, borate, and nitrite free." Whoopee! It is ethylen glycol, diethylene glycol, sodium 2-ethyl hexanoate, and neodecanoate. I presume the latter two are the corrosion inhibitors and they don't sound very photographically active.
As is known, the phenidone and ascorbic acid readily dissolved in the hot glycol. A further experiment with a new batch of the glycol showed that sodium sulfite does not dissolve. Oh well, I was trying to emulate Xtol in that matter. I guess it will have to be added separately.
Then I wondered about the sodium metaborate/Kodalk/Balanced Alkali. It went into solution like sugar in water. I put 1/4 tsp in 100ml of glycol, which is about 1.2 grams. I then diluted it 1:9 and got a pH of 9.1. I doubled the water and the pH is 8.6. Doubling again to 400ml, down to 8.2. Very effective buffering. Obviously one can alter the amount of metaborate to meet a target pH in dilution.
So is there a reason to prefer TEA over metaborate? Does TEA offer any buffering action? Metaborate sure doesn't smell bad as many posters frequently remind us.
What say you?
I've decided to go with a lot of flow and look into ascorbic acid developers. Seems to have the results I've been looking for down other, less productive roads. I've not tried Xtol because of the 5 liter thing, times dilution, just unappealing.
Closer to my interest is the PC-Glycol and PC TEA work started by Patrick Gainer. Especially the former so that I could twiddle with accelerators. I'd not bought either glycol or TEA because I wasn't sure I wanted to spend the money (especially for shipping liquid).
So I recently checked out my Prestone Extended Life Anti-Freeze. Whaddya know, the chemicals I recall being in there decades ago are gone: "Silicate, phosphate, borate, and nitrite free." Whoopee! It is ethylen glycol, diethylene glycol, sodium 2-ethyl hexanoate, and neodecanoate. I presume the latter two are the corrosion inhibitors and they don't sound very photographically active.
As is known, the phenidone and ascorbic acid readily dissolved in the hot glycol. A further experiment with a new batch of the glycol showed that sodium sulfite does not dissolve. Oh well, I was trying to emulate Xtol in that matter. I guess it will have to be added separately.
Then I wondered about the sodium metaborate/Kodalk/Balanced Alkali. It went into solution like sugar in water. I put 1/4 tsp in 100ml of glycol, which is about 1.2 grams. I then diluted it 1:9 and got a pH of 9.1. I doubled the water and the pH is 8.6. Doubling again to 400ml, down to 8.2. Very effective buffering. Obviously one can alter the amount of metaborate to meet a target pH in dilution.
So is there a reason to prefer TEA over metaborate? Does TEA offer any buffering action? Metaborate sure doesn't smell bad as many posters frequently remind us.
What say you?