Sodium Hydroxide with Pyrocat..????

patrickjames

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I read somewhere that a 10% solution of NaOH can be substituted for the Pot. Carb. in sol. B. I was wondering if anyone uses NaOH with Pyrocat (I use Pyrocat-P) and how it affects your negatives. I am assuming that you get shorter development times and pay the price with more grain with a possibility of increased base fog (but maybe not so with the p-aminophenol).

Anyone have any opinions or preferably experience?

Patrick
 

sanking

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Patrick,

It works, and is one of the alternative variants of Pyrocat-HD that I have proposed. See here, http://unblinkingeye.com/Articles/PCat/PCat2/pcat2.html

You are about spot on as regards results. For cons, expect slightly more pronounced grain, and a bit more B+F. There are no pros as best I could determine, except for the fact that you can buy Red Devil Lye (sodium hydroxide) at the local grocery store.

But feel free to use either sodium or potassium hydroxide in place of the carbonates if that is what you have. It will definitely work.

Sandy King






 

gainer

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The pH can be tempered with borax. I arrived at a solution of sodium hydroxide and borax that seems to work as well as the carbonate solution, and I think I reported it here some time ago, but I can remember neither the formula nor the date of reporting. 69 grams of borax and 14.5 grams of NaOH make a pretty close approximation to 10% sodium metaborate when enough water is added to make a liter.

It may be that the biggest problem with pure NaOH is too much local change in pH during development. This may be exactly what is needed for compensating stand or semi-stand development of high contrast scenes.

I would experiment with sodium metaborate. A saturated solution may offer the range of activity you want, is safer than NaOH, and is easily obtained.
 

john_s

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I think I read somewhere in the early days of Pyrocat when it was PMC, maybe on rec.photo.darkroom, that borax and pyrocatechol don't make a good combination. I'll try to find a reference.
 
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patrickjames

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Thanks guys! You reinforced what I was thinking. Patrick, that is an interesting thought to add the Borax. I will see if I can dig that up. My biggest hesitation is producing any base fog. I am not too worried about the grain, as long as it is sharp!

John, that would be great if run across that information about Borax and pyrocatechol.

The reason I am asking these questions is that I am out of developer, and need to order more to do some testing before I head out on the road for a few months.

Patrick
 

philsweeney

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I have used sodium hydroxide quite a bit. All was for negatives to contact print. At one point I had convinced myself the contact prints were sharper from the grain increase and I would not say any increased fog was a problem. I also think I may have gotten better results and smoother skies with the potassium carbonate. I stopped using the sodium hydroxide when I started using pyrocat for semistand as I worked out my dev times using potassium carbonate.
 

sanking

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Pyrocatechol has a rather high pH development threshold, about pH 10.0 or so. If you use a 30% solution of sodium metaborate, and mix the working Pyrocat solution 1 part A + 1 part B + 100 parts water you will get a pH of about 9.2-9.6 for the working solution, as in PMK. This is too low to do much development with pyrocatechol.

Iit is possible to mix some potassium or sodium hydroxide with the metaborate to produce a working pH over 10.0. I don't believe this would change the working characteristics of Pyrocat using the carbonates but can not say for sure since I have never done this.

Sandy





john_s said:
I think I read somewhere in the early days of Pyrocat when it was PMC, maybe on rec.photo.darkroom, that borax and pyrocatechol don't make a good combination. I'll try to find a reference.
Click to expand...
 

jim appleyard

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sanking said:
Patrick,

except for the fact that you can buy Red Devil Lye (sodium hydroxide) at the local grocery store.

Sandy King
Click to expand...

Sandy, I don't think this is true anymore. I've read where sod. hydroxide is a componant of meth and was voluntarily taken off the shelves. You can no longer find it on the shelves here.

At least there's still Artcraft, Formualry and others.
 

sanking

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Interesting, I was not aware of that. Last time I bought it at the grocery store was three or four years ago.

BTW, I lost a nice electronic scale with accuracy to 0.01g a couple of years ago to one of these meth heads. We had this guy doing some painting in the house, not aware of his habits, and the scales disappeared. The idiot also stole a check from my wife and forged it.

Sandy




jim appleyard said:
Sandy, I don't think this is true anymore. I've read where sod. hydroxide is a componant of meth and was voluntarily taken off the shelves. You can no longer find it on the shelves here.

At least there's still Artcraft, Formualry and others.
Click to expand...
 

gainer

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My only reason for seeking a non-carbonate activator was the calcium in my tap water, which causes a cloudy precipitate and could in fact reduce the pH. I'm sure I had a higher concentration of NaOH than you would find in even saturated metaborate, but I lost track of my recipe. If you use softened or distilled water, why not use the carbonate?

I can no longer get the NaOH locally, but I can get slaked lime and sodium carbonate, from which I can make NaOH.
 
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patrickjames

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Thanks for all the replies. I guess I will just try it both ways and see what happens. Anyone want to hazard a guess as to how much faster the developing times will be with the 10% NaOH? I think I am in the 12min range right now.

Patrick
 

mrred

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I know I am waking up an old thread, but the following does work.

750ml distilled water
75 g sodium hydroxide
35 g borax
water to make 1l

I kept adding the borax until I got the grain under control and I think the grain is better than the standard alkali.
 

mrred

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It's the one for the 1:1:100 . Gainer (in this thread) suggests a version, but only gives a ph just above 9. It is not heavy enough for catechol. I reduced the %10 lye solution Sandy suggested and wanted to find how much lower I could reduce it. At that point I fine tuned it with the borax.

You may have to adjust your times slightly, but I found it in the ball park.
 

removedacct3

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I too know that I am waking up an old thread, but this alkali works wonderful with Hypercat instead of the 'standard' sodium carbonate. I am using it 1 + 1 + 100.
 
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