Originally Posted by
mgnostic
Yeah, if the fuel is starting to turn brown the oil has probably started to polymerize. Given enough time and exposure to oxygen almost any oil will turn to varnish. As for props the ones you mainly have to be careful with are the old fashioned white nylon props. They dry out and get brittle. Back in the day people used to boil them to restore their proper moisture content but by now I wouldn't use one for anything but display. I would say the same goes for novelty props such as clear plastic.
I remember the white nylon props and the boil recommendation. IIRC they were from Topflite and had red lettering. I probably still have a few lying around somewhere. The ones in question are grey APC props.