Glycol-Metaborate instead of TEA?
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?
Yeah, there is a reason. Don't pour your borate solutions out anywhere near citrus trees. Kodak originally eliminated borates from EP3 and C-41 among other color processes due to complaints from the citrus industy of California and Fla due to borate toxicity!
If it works, use it. However. I think the pH of TEA is a bit higher. Why not mix the PC in glycol and whatever alkali you want in a separate solution? I think this approach would give the greatest versatility for experimentation.
Originally Posted by Photo Engineer
With all due respect, PE, you are a stuck record on this. Have you ever heard of anyone dumping used developer around their grapefruit?
Tons more boron in the air or from Twenty Mule Team in the laundry than any few grams in a liter of developer.
I think the metaborate will give you pretty much what you want. I only tested that little bit, I'm sure it can be many times over. As you probably know, metaborate has a nice long line of linearity between quantity and pH.
Originally Posted by gainer
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[QUOTE=Paul Verizzo;779492]... Have you ever heard of anyone dumping used developer around their grapefruit?
It wouldn't surprise me. Hey, truth is stranger than fiction. Just go to darwinawards.com for some pretty dumb stuff.
Originally Posted by Paul Verizzo
No, I don't expect you or anyone to dump their effluent around their grapefruit, but the effluent from photo labs in Fla and Cal were enough to have the photo industry become aware of the problem. I don't want to see that problem perpetuated if it is not necessary.
I had heard that Fla and Cal were going to ban 20 mule team borax way back then as well just like phosphates, but I believe nothing came of it, even though at that time, as you say, more borax came from laundry than photofinishing.
So, who can explain why there was a reaction. I just want you to be aware of it, and as you seem to indicate, you are aware of it in spite of your question and intend to go ahead anyhow. So, what can I say.
Go ahead, use it. I really have no further say in the matter.
Wadeaminit!!. Are you guys telling me I can mix some developers in modern-day Prestone?
John, Mount Vernon, Virginia USA
Sodium 2-ethylhexanoate and sodium decanoate are surfactants. You may get foaming in your developer working solution, depending on their concentration. As for TEA, it does form a good buffer at around pH 7.8 (IIRC).
One interesting use of borates is in insect control -- if you mix a little borax with lots of sugar and make a syrupy solution, "nesting" bugs like bees will eat it and take it back to their hives / nests. Bye-bye bugs.
"sodium metaborate/Kodalk/Balanced Alkali.
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."
A 10 fold dilution of an acid (Like HCl) OR base (LIKE NaOH) with NO buffering will show a ONE pH unit change. I don't know why you would get such a large change in pH with just doubling (twice) the amount of water. Are you using pH test strips that may be interacting in a strange way with the other chemicals in your mix?
Last edited by brianmquinn; 04-07-2009 at 09:48 PM. Click to view previous post history.