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.
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.
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