Boating and Sailing.pdf - Moja ladja

Chapter 3: Picking a Proper Prop
Fishermen like stainless steel because it can bounce off a submerged stump or oyster bar
without turning into origami. And if the prop does get slightly bent, you can often
straighten it out yourself with a hammer and pliers. Aluminums that get cobbled up have
to make a trip to the heli-arc welding shop. However, because stainless is so tough, a hard
strike on rocks can be transmitted to the prop shaft or gears of the lower unit and cause
damage there, which is much more expensive to repair than the prop.
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Stainless-steel props are relatively
expensive but are so
tough that they may outlast
your motor. They’re also best
for high-performance boats.
(Photo credit: Mach Propellers)
Stainless props ain’t cheap. Prices start at around $300, and some of the high-performance
models cost over $600. But one stainless prop will outlast a half-dozen aluminums in
tough duty.
Bronzed Warriors
Bronze props are rarely seen on small boats, but they’re the choice for many large yachts.
Bronze offers good strength, but not so much that it will snap off the stainless drive shaft
and make a hole in the bottom of an inboard boat, which is one of the reasons that it’s a
preferred material for big inboards.
Small bronze props cost about the same as stainless. Big-yacht props, usually four-bladers
measuring up to 36 inches across, can cost thousands of dollars. Bronze props have an
indefinite life span and in many cases will last as long as stainless.
Plastic Props
Plastic is … well, plastic. Plastic is a nice thing to make computer disks from. It’s good for
fishing lures, coolers, and a lot of other things. But plastic is not the best material to put
on the end of the prop shaft of an internal combustion engine that can generate a couple
hundred horsepower.