I have used all sorts of chem storage strategies and an absolutely full glass container seems to be foolproof for stock D-76. But of course I don't always have a full container and enough marbles to take up the slack just doesn't interest me. (what do you do with all those contaminated marbles when not using them?).
So when someone on that other forum mentioned using Propane to displace the air in a part filled container it got me interested, but.... Is it a good idea? Propane will displace the oxygen but will it contaminate the developer, fix, toner etc. Supposedly this is a poor mans copy of a product sold for this purpose by tetanol (sp?).
Is this more internet folklore or an actual good working solution? No pun intended.
Since oxidation is the primary concern in storage of photochemicals anything used to displace air (oxygen) would seem to be beneficial. The chemical makeup of propane is C3H8 and does not contain any oxygen in and of itself.
However, in this instance there are factors which must be weighed. Among those is safety. Propane is a flammable substance. Any usage of propane should be prudent and within the parameters for which it is intended.
There are other gases which are capable of displacing oxygen and possessing of a far greater degree of safety. Among those would be nitrogen and argon.
There are other gases which are capable of displacing oxygen and possessing of a far greater degree of safety. Among those would be nitrogen and argon.[/quote]
Very true but the main attraction of propane is that it is cheap and easy to get. I have also heard that nitrogen (don't know about argon) is not good as it is lighter than air and therefore doesn't stay in the container.
Another gas which potentially could be used in lieu of Nitrogen and Argon and that would still be safer then propane would be R 134A refrigerant. I don't believe that it would be nearly as flammable and it does not contain any oxygen in and of itself. It is available at most auto parts stores, Walmart etc. However, I would not discharge it inside an inhabited space, nor for that matter would I discharge propane under those same conditions. When I weigh the value of my A** to a little wasted developer the "apples and oranges" comparison becomes very apparent. But, hey, it's your deal...your mileage may vary.
It seems that dust off is the poor mans tetanol. The simplest thing would be one shot developer made to working strength. Easy enough to do if you mix your own chemicals. I guess the next thing would be a series of smaller bottles.
Personally I have the same fears about propane. Worse isn't it heavier then air? I really don't want to worry about it leaking in the basement.
Hmm......valid concerns about propane. I guess I am a little sanguine about it as I have for years used a lot of it in plumbing and camping but would never use it on a boat because it is heavier than air. I'll have to give that side of the question a little more thought.
Robert, what is in dust off? I have thought of that also but it doesn't list any contents on my can of Enviro Duster. Haven't bought Dust Off for years so I don't know what it might list.
Yep, I could use another dev or a bunch of small containers, but I like D-76 and mix it in a gallon ahead of time. Decant to 1/2 gallons but that leaves a lot of oxygen in the jugs as it is used up.
I am trying to avoid decanting to a bunch of liter size plastic bottles. But I don't want to get blown up either :twisted:
I still say that collapsable bladders like those used for hiking/camping are the easiest and best solution. Many of my chemistry (I buy 5-15 gallons at a time) comes in these, which is where I got the idea. Also depending on your desires, those vacuum seal kitchen bags (used to be called seal-a-meals) work quite well. I never used mine at home so I hauled it to work and viola!, get use now. And as it gets used down you can just cut off the extra length and re-seal. Or throw away and start again. When they need darkness for storage, I simply put that bag/bladder in a black plastic overlay.
We actually can't get dust off locally. It looks like a locally made knockoff is the only thing available.
See if that works. If I remember right when I check it out dust off is similar.
I wasn't suggesting switching developers but mixing your own d-76. While you aren't likely to save any money by mixing your own you never have to worry about old developer.
I use D-23 and mix up whatever wierd amount I need. No need to store it. If you aren't using it stock then it should be easier to get everything mixed into the solution.
Of course there's Protectan made by Tetenal. (No longer available in the US?) And...the old photographer's trick: a drop of ether.