Aqualloy 17 vs 22
Posted: Aug 13th, '19, 18:46
Sorry -- the price difference begs the question... I've called 4 machine shops in the New Orleans area (including Bayou Machine -- thanks Danny) and they all stock Aqualloy 17 and make a lot of shafts for the commercial shrimping and oil industry. They get very few requests for 22 and when they do, the cost is literally twice as much (shipping is a bid factor). I fish in salt water but dock in Venice -- fresh water. The boat sits idle for extended periods of time so there is the possibility for crevice corrosion -- but less since the boat docks in fresh water. I get very few if any barnacles on the shaft but lots of algae and some kind of calcium deposits which may become corrosion sites as well. Cheapest place I found for 22 is Deep Blue Yacht Supply on line at approx. $1000 per shaft...
Have to say I'm leaning toward 17. Somebody talk me out of it!.
A total shaft length question- I measure 78 inches from the coupling to the back of the strut. Plus the standard taper and thread length. How much should I add to ensure I get .8 x the shaft diameter between the strut and the prop? What's throwing me is the prop does not seat at the start of the taper (which I thought was odd since seating further down the taper would not take advantage of the full shaft thickness -- and may have prevented failure in the first place).
Have to say I'm leaning toward 17. Somebody talk me out of it!.
A total shaft length question- I measure 78 inches from the coupling to the back of the strut. Plus the standard taper and thread length. How much should I add to ensure I get .8 x the shaft diameter between the strut and the prop? What's throwing me is the prop does not seat at the start of the taper (which I thought was odd since seating further down the taper would not take advantage of the full shaft thickness -- and may have prevented failure in the first place).