When using items to repair things (epoxy, (leather) sewing kits, ducttape) and its quantity is below 25%, u can still repair an item - even with just 1% left - its enough to repair something from badly damaged to damaged or from damaged to worn. This is fine for me.
But... the same mechanic should be used for the gascanisters used with the blowtorch.
Example: A small gascanister filled to about a third (theres no perentage display for the canisters) will start repairing a damaged vehicle engine (or other vehicle parts). It will play its repair animation, but then suddenly the action gets aborted - as there seemingly wasnt enough gas in the canister. Result: the engine keeps its damage status, but the canister already lost the gas that has been used during that process. In theory u could use a hundred small gas canisters with about a third left on that engine with no improvemts to it - but the gas will be used anyway.
Suggestion: Don't give us the option to repair damaged engines in the first place if there isn't enough gas left in a canister, without wasting gas for nothing.
Or: Allow us to repair it regardless, no matter how much is left in a gascanister (as the ducttape and sewing kits do).
Or: Allow us to repair the subleves of damage states. (repair it from damaged (max) to damaged (min) for example, so the used gas has at least a tiny effect and maybe 2, 3 nearly empty cans could fix an engine.