RE: Airplane long storage
I met a guy at the flying field who had a Saito 30 for sale. He said he had it submerged in a gallon can of motor oil so there would be no rust.
I followed him to his house and sure enough, the Saito 30 was submerged in a covered can of clean motor oil.
I bought the engine
When I got home, I drained the motor oil from the engine and immediately noticed the bearings were rough
I disassembled the engine and there was the most rust I had ever seen in a model engine. The motor oil did nothing to prevent the damage from the acids. There were rust pockets on anything that would rust.
I was able to clean the engine and replace the bearings