Quote:
Originally Posted by Botnst
Around here we use stainless props on all of our boats except the 2 with Go-Devils and the airboats, which have composite props. We have about 20 boats in our fleet that vary from 20 hp to about 150 or so. Mostly Evinrudes and Johnsons. We've been using stainless since the early 1990's. I have not heard of a need for a lower unit replacement yet. Oh yeah, there was the whaler with the twin I/O's that we converted to outboards. But IIRC that was due to a maintenance issue not mechanical damage.
Not saying that stainless props don't have the problem, just that we haven't seen it.
My s-in-law swears by bronze on his Chriscraft. There are repair shops around here that rebuild props and I guess bronze are good for that. What do they use on offshore workboats and shrimp boats? Anybody know?
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Because stainless is stronger than aluminum, stainless props can have a thinner cross section so they take less hp to turn a given rpm.
In another life, I was an production inspector and boat test assistant for
Robert R. Hammond and Associates. That was about the time stainless props were appearing on higher-end runabouts as a 'performance' option. For example, our 19' models powered with a 350ci Chevrolet MerCruiser would run about 4-6 mph faster with a stainless wheel.
They weren't without issues back then. With startling frequency they'd spin out the rubber shock absorbing material in the hub. Since we did most of our engine and boat testing in the dead of winter, I became pretty good at craning off the back of the boat while someone held onto my ankles and I changed out a dead prop without actually getting totally wet.
I can testify that when you tag soft bottom with one of those stainless props, it would just fold the blade back a bit and not break it off.