prop storage
My prop spent also several years in a living room, in the original shipping box, serving as a “bench” for my cat to look out a window (his idea, not mine…but no issues with him doing that). I did not take any special precautions, mostly because it was already in a temperature controlled environment with reasonable humidity levels. It worked out ok, and the prop functioned fine from the first flight on.
Hartzell doesn’t have any long term storage instructions described in the owner’s manual (at least none in mine). They do list calendar time limits for overhaul or re-seal, as well as for flight time. The calendar time between overhaul (for mine) is set at 72 months. People can (and probably will) debate that, but those are Hartzell’s numbers, likely based on the fact they have no idea how a prop (flying, or not) has been stored….indoors, outdoors, humidity level, typical weather exposure, condition of the prop grease, etc. So their number may be on the conservative side, but there it is.
As to filling the hub with oil, I personally would not. During normal ops, the oil from the crankshaft does not enter the blade pitch the control mechanism side of the hub. If it did, it would wash the grease out, causing some grief (re-seal or overhaul time). So, keep it safely stored, and then figure out how to deal with the overhaul time limit when it comes up. I have exceeded the time limit, but I am planning on a re-seal or overhaul next condition inspection……it’s due.