I'd like someone with a developer chemistry background to comment on why Dust-Off or similar products might affect the activity of XTOL. It's not obvious to me why the main ingredient would (but I'm not a chemist). OTOH the manufacturer isn't obligated to list every ingredient on the label, so who knows what's in there. (Note-- I've used Dust-Off to preserve XTOL for years and have not noticed any problems with it, but I use it to make pictures, not exposure/density curves.)
I can second the commenter who advised against using CO2. That will tend to acidify the developer (if in a water solution), which is not what we want.
I believe that dry nitrogen has been sold in aerosol-type cans for preserving partially-consumed bottles of wine, whatever those are. Maybe that is still available. Nitrogen is quite inert at room temperature. Though it wasn't a cheap as Dust-Off, as I recall.
Nitrogen from a gas supply place will be the cheapest vs. Argon or something like that. Find a good welding supply place and a 25lb tank will last forever. A single-stage regulator should handle bringing it down to 4-5psi or so.
I have a welding tank like this but it's filled currently with an argon/co2 mix (75/25) so I need a pure nitrogen tank too probably.
I'm too cheap to use canned air. I've been using wine bladders.
“We are buried beneath the weight of information, which is being confused with knowledge; quantity is being confused with abundance and wealth with happiness.
We are monkeys with money and guns.”
― Tom Waits
The problem I have with Nitrogen high-pressure tanks is that over here they have to be opened and examined after a while. If one buys a large one to save on the refills, it easily can be that before even the first refill it has to go to technical examination.
Originally Posted by EdSawyer
Yes, we Germans...
I like the bladder thingy - will try that if and when I try X-TOL. Another cheap and hassle free option is butane gas (lighter fuel). It is keeping my SPUR developers (HRX, Acurol-N) quite fresh.
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Welder's Argon in 1-2L canisters is cheaper on a cost per volume basis. A 1L canister costs about A$25 plus a one time buy screw on regulator costs about A$25.
Originally Posted by timhenrion
Holding 110L (at 1atm) it has much more volume than bloxygen which only holds about 7.3L at 1 atmosphere (detailed calcs available on request) yet costs about A$20.
Welding canister with regulator=A$0.45/L
Welding canister without regulator=A$0.22/L
From what I've been able to understand, the main advantage of argon is that it is heavier than nitrogen and air which can 'blanket' the chemical's surface. I found the following an interesting read
Since this old thread is resurrected anyway...
I bought wide-mouth glass amber bottles and many glass marbles. When a chemical is partially used I can just drop a few marbles into the bottle to displace the air and re-cap. No gas to use up. No worries other than ensuring I place the used marbles in a colander and rinse thoroughly in hot water before using again. Easy easy easy... no complications... nothing to think about.
Very interesting and very weird. The gas in canned "air" is of the Freon family and has an assigned number. It's closely related to R-134a used in car A/C's. (As a side note I have very successfully used a butane/propane mixture in a car requiring the old R-12.)
One would think it would be inert, but apparently not.
A lot of expensive or inconvenient ideas here. I guess if I needed to "de-air" my bottles, I'd just shoot some propane in from my propane torch. Handy, cheap. Just don't smoke around your Xtol! Ha ha..
BTW, I've harped on this before, but this is a good place to re-harp: PET plastic water and drink bottles are NOT impermeable to gases, including water vapor. Set one of those thin water bottles unopened somewhere and wait a few months. It will be partially collapsed as the water migrates outward.
I use, mostly, 1 liter sparking water bottles, much thicker. For developers intended for long storage, I spray with a few layers of lacquer. My research on preserving injet prints led me into all these weird, dark corners about permeability. Lacquer is almost as good as glass or metal. In fact, cellophone is relatively permeable, so it's sprayed with lacquer to keep your Twinkies fresh.
PET has less gas permeability than LDPE or HDPE.
Originally Posted by Paul Verizzo
At least over here you even can get bottles for still water in two thicknesses.
Not true. Sorry, I'm not going to spend a lot of time linking you to my references. For instance, the original Saran wrap was hugely impermeable, the "upgrade" from ten"???? years ago, is just LDPE.
Originally Posted by AgX
The bottom line remains PET is permeable.