HE-1 is not recommended by Haist
HE-1 (and complete hypo removal) is not recommended by Grant Haist in his book: Modern Photographic Processing.
Originally Posted by Brickbird
Best to use sodium sulfite based HCA, instead.
Everything is analog - even digital :D
Anchell's book says about 7.9 grams per teaspoon for sodium sulfite anhydrous.
Originally Posted by David Brown
For sodium bisulfite about 5.5 grams per teaspoon.
How do you practice your scales?
We shall come rejoicing, bringing in the sheets.
The thing about clearing is that you need enough and no more. And every paper is different. For instance Rives BFK is a beautiful paper, but a real bite in the butt to clear. In contrast, Cranes clears very easily. The point being that you need to experiment a little bit and figure out what concentration and time you need to adequately clear any given paper. I used to mix up a home brew hypoclear as follows:
1 teaspoon sodium bisulfite in a liter of warm water and stir until dissolved, then
1 tbsp of sodium sulfite
1 tbsp of EDTA.
This would generally clear COT320 with three five minute baths.
It is advisable when you are first using a new paper to mask the border and check your clearing by holding your paper up to a light and seeing if you can detect residual ferric oxalate. There is also a chemical test that, if I remember correctly, involves adding a little drop of a potassium ferricyanide solution to a supposedly cleared area. You'll have to google that one. I like the visual check.
If it isn't clearing, check the pH of your clearing baths. If they are above 7, you are just pissing into the wind. Some stubborn papers may require a first bath of phosphoric acid or even dilute (1-2%)hydrochloric acid. Just be aware that if you throw a piece of paper that has spent five minutes in a hydrochloric acid bath straight into a tray containing sodium sulfite, you may think you have a rotten egg somewhere in your darkroom. So it is a good idea to briefly rinse the paper after the acid bath if you are using a strong acid as a clearing agent. It is not an exact science, as you can see from this rambling post.....
fully agree clay.
Ive learned, from many foul ups, that my clearing baths vary for different papers. for instance, in my experience, FA EW clear very well in 1L water, 2 tbsp HCA, 1 tbsp of EDTA. While Cranes Cover will clear fairly easily in 1L water and just the HCA (2 tbsp). The one common denominator Ive noticed is that I use HCA in some ratio in all my clearing baths, regardless of paper. Hence my desire to find a nice "home brew" method of mixing up HCA to similar ratios as the packaged Kodak version.
Instead of mxing my dry chems of Sodium Sulfite and Sodium Metabisulfite I think I may just test out the tablespooning method as you mentioned clay. Thinking Ill give a shot tonite with: 1L hot water, 2 tbsp sodium sulfite, 1 tbsp sodium metabisulfite a shot and see how it works for me.
Seems like this would be an easier way to just spoon out the dry chems in the trays and not have to deal with adequately mixing the dry powders together.
thanks for the info and the measurements.
Alas, Lee, this is why my piano playing never got that good. Turned me into one heck of a drummer in the day, though.
Originally Posted by Lee L
"I got rhythm, I got music ..."
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Matt, I actually use a citric acid bath first followed by 2 clearing baths clay described above and haven't had a problem with any paper i've used.
Let's see what I've got in the magic trash can for Mateo!
Originally Posted by David Brown
I'm kinda working from memory here but, if you can find Patrick Gainer's teaspoon receipe fro Kodak D-23, you can verify this...
for Sodium Sulfite, I believe 4 Tablespoons is about 100grams. It might be 4 Tablespoons plus one teaspoon...
so, 200g of Sodium Sulfite would be something like 8 or 9 Tablespoons
I use Heico Permaclear for clearing Pt/Pd and it works very well, even on combinations which are tradionally "difficult" to clear - I use 3 5 minute baths of working solution (3oz to a gallon). You can buy this stuff from Calumet shipped to your door for under $50 and that's enough for about 50 gallons of working solution. It really doesn't add any cost to your process.