XF20

[jacquesmm]

No need to apologize, that thread was interesting.

[tboggs]

I'm not sure if it would work for the XF20 but if someone were absolutely certain they needed poly sheathing on their hull maybe a mounting framework could be installed in the boat. Basically 2x2's incorporated into the interior of the hull for mounting the poly sheets. That way you've got a bit more material for the mounting screws to hold on to and it may help distribute the stress a bit more, especially if you have a serious impact.

[jacquesmm]

We worked very hard on making that boat as light as possible.
Instead of polyethylene, I would add a sacrificial layer of glass and renew it every season but I am not convinced that it is necessary.
We are testing a carbon (graphite) bottom right now and GaryP is testing the polyethylene.

[Riverman]

Just a thought here since I have worked this out before. You can buy UMWH thinner than 1/2", I think down to 1/8" or 1/16" at industrial supply houses like MSC. You could also mount thin strips which would still give protection, plus it would be easily replacable and much cheaper than buying whole sheets. I myself would not mount it with wood screws, but a machine screw. Predrill a 1/4" batten and UMWH strip for flanged threaded SS hardware (T nuts, commonly available). Epoxy batten to hull like normal runners, hardware will be held in place by hardware flange hull side of batten strip. Screw on UMWH runner with a few SS machine screws. Easily replacable thereafter, but I bet by the time they wore, you may have other structural problems. I have used this stuff for industrial bending of steel tubing up to 4" diamter and with little finish scratch to surface. That is TOUGH, very Tough. Delrin would be another good choice, but it is more spendy. A also have seen strips of polyethelene on 50' rolls.
I think strips would be a great way to go. The rivers where I live are loaded with basalt, (Canadian Shield Rock) and that is sharp stuff. Jacques, you probably remember those type lakes and rivers when you lived in Montreal, I think it was Montreal????? Oh well, just a thought.
Jacques, too bad there was not enough call for this, you could sell kits. You know, I think we need to have our kids teach us boatbuilders to just say no when it comes to wood screws in the hull, or transom. By the way, this is great way to mount a transducer on the transom for both function and looks. I epoxy a coat a piece of mahogany to transom with hardware implanted. Sacrificial if need be, and easy to replace or to switch a transducer.

[jacquesmm]

Gray Pratt may sell kits.