Galling Problem

Most of you know the rebuilt props are not as good as a new prop. They are thicker and heavier which makes them about 1 or 2 mph slower and they seem more prone to cracking near the hub when you beat a lot of rocks. In spite of this I will continue to use the rebuilt props because the price is right. Last fall I came across a new concern when installing a rebuilt prop. While screwing it on the shaft it seemed a little tight but it was going on by hand, right up until the threads started to emerge from the prop.

Suddenly it stopped turning, and even worse it was so tight it wouldn't unscrew. I tried WD-40, heat and longer breaker bars. Eventually the shaft twisted off just above the prop. What happened is a nasty characteristic of stainless steel called galling and I hope no one else has to experience it. If you are turning on a rebuilt prop and it is tight, back it off quick! Take the prop to a 3/4-10 tap and run it through the prop from both sides. That should clean the threads out enough so it will turn on freely without locking up.