Gilbert Park was getting his boat ready for a 300-mile cruise and decided to give the back end a good survey. The rudders looked fine, but the starboard propeller had some pock-marks that indicated electrolysis.
Park wasn’t sure if the prop needed to be replaced or repaired but he knew he needed to take it to the local propeller store to get a professional opinion. And, that meant he had to pull the prop off the shaft.
Once the split pin and nuts were removed, Park tried a bit of old-fashioned brute force. Despite a big hammer and a block of wood in hand, he could not get the prop to move. What he needed was a desiccated prop puller, which is neither easy to find nor inexpensive to buy.
He finally was able to rent a puller from a local mechanic and after a series of tries, the prop broke free. Looking at it closely, he was bracing himself for the expense of buying a new one.
But, the pros at the prop shop told him the prop was fine and could easily be repaired, which they did in only three-days and at a nominal cost. That was the good news.
Reinstalling the repaired prop was going to be the hard part and Park thought he had a sensible plan involving dollops of grease, a new key, Loctite for the nuts and a large wrench for tightening. But as it turned out, the pros at the prop shot had a better way.
It turns out you do not want to coat the shaft and key with grease since that will prevent the shaft and prop from bonding metal against metal. The grease will eventually wash away leaving small spaces between the shaft and prop. Not good.
Instead, Park was instructed to clean tthe shaft and the prop thoroughly and then slide the prop onto the shaft without the key and tighten up the nuts.
He was told to mark the shaft’s threads when the nuts were fully tight and then remove the shat again and place the key in the keyway before reinstalling the prop. That way he could be confident the prop was as tightly fixed to the shaft as possible.
The operation was a success, the patient lived and Park was soon ready for his 300-mile cruise.
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