Title says it all. Is it intended? I spent a week crafting massive quantities of Acetylene only to realize all my O2 is unusable 
Is that it, or is it that you donât yet have a tool with the pressurizing quality? I havenât gotten that far into a game in recent days yet, so I canât say for sure, but your oxygen should very well be usable if you have the correct tool.
I actually found the correct item, you need an oxygen cylinder containing oxygen (whereas the oxygen tanks and emergency packs have no contents, only charges). Iâm still wondering if this is intentional, maybe medical O2 is actually a mixed gas?
Fun fact: the O2 cylinder is something like 900 pounds 
Iâm putting them new hauling mechanics to good use!
How rare are oxygen cylinders? Iâve searched 5 laboratories (2 rectangular and 3 randomly shaped), but didnât found any cylinder with oxygen inside, only âemptyâ ones.
It looks strange, because there were many carbide and âemptyâ oxygen cylinders in those laboratories, and several acetylene gas machines.
Also, all nitrogen and hydrogen cylinders Iâve seen so far are also empty. I think there were some craft recipes for scuba tank, which require nitrogen, and I suppose hydrogen from cylinders can be converted into âsolid hydrogen cellsâ by some laboratory machine Iâve never seen yet.
Am I just extremely unlucky, or gas cylinder with content are very rare?
the acetylene torch now uses âwelding tanksâ, so searching specifically for an oxygen cylinder for it is a bit silly now. if you run across two tanks with both oxygen and acetylene, you can craft combine them into oxyacetylene to stuff into a welding tank or small welding tank⌠and thats the only way to refill/refuel them.
Iâve tried to find an oxygen cylinder containing oxygen using debug, and didnât find any.
Does anyone knows what exact item contains oxygen for crafting recipe?
From what I see in current experimental, oxygen tanks and emergency oxygen packs canât be used to craft oxyacetylene. And oxygen cylinders which can be found in ânew-style labsâ also canât be used for that craft. Debug mode shows that âoxygen cylinderâ also has charges (300 charges, but they are hidden in real game for some reason)
I suppose something is broken in game, please help me to find out details, so I would be able to create github issue with detailed description.
Edit: looks like we already have an issue for this: Oxyacetylene cannot be crafted ¡ Issue #40275 ¡ CleverRaven/Cataclysm-DDA ¡ GitHub
d⌠did you not read what i just posted there?
the oxyacetylene torch now uses welding tanks. its been fixâd
this is on the latest experimental.
Let me explain, I am aware that acetylene torch uses welding tanks or small welding tanks, and doesnât need additional oxygen.
And you can get welding tank (with welding gas charges) in two ways: either find it on map or craft it. Crafting recipe is in âWelding and Metallurgyâ book, it uses welding tank (e.g. empty one) and oxyacetylene. And oxyacetylene crafting in turn requires oxygen. So the problem is - oxyacetylene crafting is broken because of oxygen cylinders/tanks.
okay, i misunderstood what you were trying to get across and now i understand. seeing as how this has been an issue for a while now i assume that theres an issue trying to get oxygen to work as both a charge (in the case of oxygen tanks/emergency masks) and a gas (for the cylinder)⌠so changing the recipe for oxyacetylene to use the charge instead of the gas would be the fix for this situation, as you could then use any form of it currently available.
iâll see if i can fix that.
edit: i cannot. its complicated. people are working on it.
a current workaround is this file on the bug report that will let you convert the existing recipe for oxyacetylene so it works for the existing oxygen tanks.
other than that itâll be fixed in the future when a specific building type will have acetylene gas compressors and tanks and such specifically for the purpose of creating the gas (or someone decides to make a gasoline/propane alternative recipe for âwelding gasâ)