Got a 26.5 full frame Backwater. I have a hex shaft and prop. The problem I am having is after 1-2 trips (average 2 hours a trip) the prop is loose. From the prop out I have a SS washer, SS nut, and nylock jam nut. They are all pretty well tightened. I have even used an impact driver to tighten. It's not rocket science but I am clueless as to how to prevent it. Anyone else experience this? Any suggestions? A loose prop makes a hell of a racket when spinning.

I'd replace the nylock nut.

A drop of locktite does wonders

A little more info. The play or slop that develops is the same side to side play that the hex prop has on the hex shaft before it is tightened down. Guess the shaft has rounded some causing the play. I have a spare shaft and the prop fits pretty snuggly on it so I assume the it is the shaft that is rounded out some and not the prop that is wallowed out. Talked to Jake at Backwater about it, He offered 2 solutions. 1) He said the play should not cause any issues and I could just tighten it down when it develops. 2) Go back to a threaded prop and shaft. I went with the hex shaft so I could easily remove the prop if needed. Always heard about issues with removing frozen props and nuts from a threaded shaft. I was removing the prop quite a bit while I was experimenting with the prop size and shims for the tracer plate. I have all that worked out now so removing it should be only for replacement and maybe occassional maintenance.

Using an impact can cause the nylon to strip out