510 Pyro Mixing Procedure

[luis_rives]

<p>Those of us that have use this developer are familiar with the fact that the most difficult part of the process of mixing the developer is getting the chemicals to completely mix into the TEA liquid. Here is my procedure which simplified the process:<br>

All the chems in their proportion to 400ml of TEA put into a 1 liter pyrex cup with the TEA. Using an aluminum cooking pot brought water to a boil. The pot has to be sized and the water level so that when the pyrex cup is in the pot the level that is left over after the water is displaced matches the level of the TEA in the pyrex cup. Remove pot from heat, pyrex cup in pot and stir with a long handle stainless steel small spoon that is also used to break up the solids by pressing against the side of the pyrex cup. Remove pyrex cup from pot, add some water to pot to make up for displaced and boiled off water, and bring to boil again. Repeat the entire procedure until all solids are dissolved in the TEA. Should take about three to four cycles of heating and dunking the pyrex cup in the water before the solids are completely dissolved.<br>

Happy Mixing!</p>

[Bill Bowes]

<p>Very good procedure Luis. I believe mine might be a bit easier. Pyrex cup that's has 1.0 liter capacity. Put about 100ml of the TEA into the pyrex. Now carefully place the Pyro powder on top of this small amount of TEA and allow it to sublime into the TEA for 10 minutes. Now put 300 ml of the TEA and the other weighed components into the Pyrex container. Microwave on high for two (2) minutes and check temperature while stirring. Note the temperature increase during these two minutes. Continue this process until the TEA and chemicals start to dissolve. The TEA might start to change color, but this does not seem to affect the developer in my case. Keep doing these cycles but keep the temperature just above the point where the powders are dissolving. Continue until all is dissolved and then add TEA to the 500ml mark.<br /> The only REALLY hard part of mixing 510-Pyro this way is getting every last ml out of the pyrex bowl ! It's like syrup on the pancakes. <br /> 510-Pyro was my favorite for years until I discovered Jay's Obsidian Aqua. Simple 3 chem's in a water based mix. After more than a year, I am only thru half my first liter (1 ml per roll) and the batch is still at full specs. Identical film results, so I use them both until my remaining 510 supply is gone. Bill</p>

[luis_rives]

<p>"The only REALLY hard part of mixing 510-Pyro this way is getting every last ml out of the pyrex bowl ! It's like syrup on the pancakes."<br>

I transferred the mixed dev into a plastic storage bottle and the trick is to make the transfer while the mix is still slightly hot and thus thin, but not hot enough to soften the plastic. I did not want to use the microwave because I wanted to keep the chems away from anything having to do with food prep. I found it very easy, just get the water to boil then dunk the pyrex cup, when the temp of the water drops just boil again and repeat.</p>

[luis_rives]

<p>Update: It has been brought to my attention not to use a metal mixing utensil as this can react with the ascorbic acid in the 510. Preferred stirrer is pyrex glass or plastic typically used with photo chems.</p>

[luis_rives]

<p>Bill,<br>

I took a look at OA and I am not clear on its use. There is the 3-chem stock solution that gets added (as I understand it) to a working solution of 6.66g carbonate/liter solution at a 1:500 ratio. Does the carbonate solution have to be mixed every time one is going to develop film? Please clarify this for me. Thanks.</p>

[Bill Bowes]

<p>Hello again. The "basic" mix for OA is the Cathecol and metabisulfite in water. I brew up a 1.0 liter batch and divide this into 90ml, orange colored cough syrup bottles. Filled to the top and sealed, mine are now over a year old and work excellently when opened (only into bottle 6 of 11 now).<br>

The carbonate is used just before developing to "activate" the Cathecol, the only reducing chemical in OA. I use Arm & Hammer Washing Soda which is anhydrous Sodium Carbonate...left over from my Caffenol days. Most larger food stores carry this and it is less than $10 for a life time supply.<br>

I use 1.0ml of OA per roll of film (120 or 135-36). This is diluted into 450ml DI water and a 450ml Nikor tank is used. About 10 minutes before the OA is added to this water, I dissolve 3.5g of the soda. This is the amount of soda you would find in the solution of carbonate given in Jay's direction. Weighing the small amount every time is a lot easier than having some bottle of pre-mix about. Allow the carbonate and OA to "mellow" about 5-10 minutes before starting your developing sequence.<br>

My "base" developing time for the OA is now 19 minutes, with +/- 2 minutes for the respective Zone System shifts. Neg density has been established for wet prints, although I primarily scan and digi print these days.<br>

Pic included is a cropped 35mm of a 1937 Alfa Romeo Touring Sedan drivers side window. UFX400 @ 250, K1000/135mm, OA developing, V800 scan<br>

Bill</p><div></div>

[Bill Bowes]

<p>Forgot to mention. I use a small 800 watt microwave that is only for Photo work. . . used to quick dry test strips when the wet lab print work was the activity. Bill</p>