View Full Version : Air Displacement for Developers/Fixer?
kq6up
04-08-2011, 10:14 AM
I tried to use Dust Off to displace the air in my Dektol. I did not work at all. If anything, it seemed worse then if I had just capped it. I had read that trick on-line. I was under the impression that dust off was inert. I was thinking about trying carbon dioxide. It is heavier than air and easily produced with baking soda and a weak acid. I know I could use accordion bottles, but I don't want to have to replace all my oxygen reducing chemicals with accordion bottles when I can use baking soda for nearly free. What do you guys think?
I do realize that CO2 reacts with water to form carbonic acid, and this could be an issue with alkaline developers. However, hardening fixers already have a low pH, and it might be just the trick to prevent hypo solutions from decomposing in the presence of air.
Thanks,
Chris Maness
Christopher Walrath
04-08-2011, 10:40 AM
Glass marbles. Add marbles to your bottles until the level of the chemistry reaches the top of the bottle. Make sure they are clean before you add them, though.
tkamiya
04-08-2011, 10:47 AM
I've heard of this glass marbles trick but does anyone actually do this? I can't imagine having a one gallon jug half full and displacing that much air with heavy glass marbles. The bottle will be so heavy, it might even rupture....
Christopher Walrath
04-08-2011, 10:51 AM
I decant my raw chemistry into smaller 8 ounce amber glass bottles and fill the marbles into them. As to processing chemistry I one shot so I have no need for two gallons of marbles. Not to mention, makes fine pouring a tenuous situation at the very least.
jeffreyg
04-08-2011, 10:55 AM
Amber glass apothecary bottles. Some have graduate markings. apiece of masking tape for labeling contents and date. Mix and pour into those. Simple storage and no marbles to wash.
http://www.jeffreyglasser.com/
holmburgers
04-08-2011, 11:32 AM
I'd give wine preserving pumps a shot. They suck out air, creating a vacuum. It's cheap, easy and should work well. Unfortunately you'll have to have as many of the dedicated "corks" as bottles.
nhemann
04-08-2011, 11:48 AM
If you don't mind a little cost, go to your local homebrewing store or website and get some carbonating gear (small tank, regulator, and some hose) it will last you forever with what you are doing. And no messy reaction tank. I use mine for lots of things, including blanketing my saurkraut crock - keeps the mold down perfectly!
I've used these (http://www.bhphotovideo.com/c/product/86501-REG/Doran_Plastic_Storage_Tank_5.html) successfully for many years. Note the internal floating lid which draws down on the liquid as it is drained from the integral faucet. I picked up 4 five gallon tanks as closeouts and love them. I can keep stock (mixed) Dektol for at least six months to a year even though I must throw working (tray) strength away after a 5 or 6 hour session. Although oxidation isn't nearly as big a concern, I also keep working strength fix in one, mainly for convenience.
kq6up
04-08-2011, 12:33 PM
I've used these (http://www.bhphotovideo.com/c/product/86501-REG/Doran_Plastic_Storage_Tank_5.html) successfully for many years. Note the internal floating lid which draws down on the liquid as it is drained from the integral faucet. I picked up 4 five gallon tanks as closeouts and love them. I can keep stock (mixed) Dektol for at least six months to a year even though I must throw working (tray) strength away after a 5 or 6 hour session. Although oxidation isn't nearly as big a concern, I also keep working strength fix in one, mainly for convenience.
Sounds like the containers Ansel refers to in the negative. I am not quite up to 5 gallons a year yet. It would probably start to become cash effective to mix your own developer from separate chemicals from bulk at that point. I might be teaching a photography class next year, and this would be something to look into.
Chris
pschauss
04-08-2011, 12:40 PM
I have never had a problem with Dektol. Except when I am doing 11x14 prints, I use it in a Nova slot processor, so one gallon can last at least 6 months. Until recently, I was storing it in a 1 gallon amber glass jug and it was fine even after more than six months. Now I split it up into 16 oz. bottles, more for convenience than for keeping properties.
For developing film, I use HC-110, Diafine, and Rodinal which keep indefinitely.
Rick A
04-08-2011, 01:11 PM
I store all my D-76 and paper developer in 250ml plastic bottles filled to the top and stoppered tightly.
BTW, if you're looking for a wine bottle air evac pump and corks, I have a new set to sell. It doesn't work on plastic, only glass(which I no longer use)
Use any squeezable plastic bottles. Accordion bottles are almost useless, but many soda bottles work perfectly for that purpose; displacing air by squeezing. http://www.youtube.com/watch?v=hdu4cCOrf3I
Just don't tell anyone on APUG you did that; even if you remove the original labels and label them correctly, telling on APUG will cause children to come to your place and drink all your chemicals and DIE, but that cannot happen if you buy lower-quality bottles from a photo supply store for a higher price even if you didn't label them. Good luck ;).
tkamiya
04-08-2011, 08:43 PM
OOOhhhh... Soda.... Yummy D-76.... Oooooo..... :)
Photo Engineer
04-08-2011, 08:47 PM
No inert gas will really protect an acid fix. It is the pH which "kills" it! An alkaline or neutral fix does not need protection.
PE
Bill Burk
04-08-2011, 09:46 PM
I thought I use more. But labels on my quart plastic bottles reveal I go through chemicals slowly. When I mix up a gallon, I cut four fresh seals out from a Skippy peanut butter jar seal. I fill three bottles to the top and seal them without (much) air. The short bottle is the first one I use. I use 16 ounces per darkroom "shift". I'll open a bottle and use half. Then I just close it. I don't do anything special to preserve the other half. I try to get back into the darkroom to use the other half "as soon as possible". If I know I left a half bottle more than a few weeks, I might dump it and open a fresh bottle. In my whole life, I only had one chemical failure from inactive D-76. Dektol's gone bad on me a few times, but is obvious ugly brown when it's bad. This is what I love about black and white - supplies seem to last forever. Wow the bottles tell: These are the markings on my last four gallons of Dektol 4/2004, 3/2007, 9/2009, 8/2010. I am out now and have to mix another batch.
Bill
I work for Kodak, but the opinion and position I express is my own, not Kodak's. Kodak gives clear information about how long chemicals can be expected to last.
Mark Fisher
04-08-2011, 11:10 PM
Since I went to glass bottles, my problems are gone. I have mostly 1 liter and a few 250s to decant partial bottles into. Well worth the money. Poly bottles let in a lot of oxygen. Accordian bottles trap a lot of bubbles. Glass is best. If you must use plastic, PET bottles are the next best of oxygen permeability. SKS bottles (http://www.sks-bottle.com/340c/fin1.html) is where I bought a few cases.