warning. Today I replaced the old angle bracket and screw type aluminum foot brace in my kevlar ultralight Wenonah Advantage with a Wenonah sliding foot brace and it wasn’t as straight forward as the Wenonah rep at Canoecopia had told me it would be.
1st problem: Sliding foot brace rails are longer than the old rails and hole placement is different. To resolve this, I drilled new holes in the new rails and used a larger bit to widen the slot in the rail large enough to get the rivet tool’s head into. Problem still was that my largest bit - 1/2" - wasn’t big enough to allow the the rivet tool’s head to get far enough in to pull those two rivets up completely snug, so one one of the rail is a little wobbly.
2nd problem, the mounting holes in the boat are in metal plates embedded in the foam ribs of the boat, so that when you drill the heads off of the old rivets, there’s no place for the back side of the rivet to fall away to to allow room for the new rivet, so I had to drill it right on through the outside of the hull and now have to repair the holes on the outside. I’ll probably just fill the hole with resin from the outside and put some vinyl tape over it until it sets and then remove the tape.
The end result is that I now have a sliding foot brace so that I can change it’s position when I need to change the boat trim in windy conditions, but it wasn’t nearly as straight forward as the Wenonah rep suggested.
Now that you’ve drilled through the hull
, maybe you could use very small bolts instead of rivets? You won't have any problem making them snug. The only time I use pop rivets is when there is no access to the "other side".
By the way, from an engineering standpoint, you WANT those rails to be firmly attached. With a force oriented as it is in this situation, loose fasteners rely only on their own shear strength, which in pop rivets is pretty minimal. When the fasteners are tight, all they do is remain in tension, and the resulting friction between the two pieces that are clamped together carries the load that OTHERWISE would impart a shear force to the fasteners (to illustrate this a little better, that's also the reason why the wheel lugs on your car will usually break after a while if the nuts are loose, but they will never break if the nuts are tight).
on a flex core hull
I have installed the new braces in my year 2000 flex core Voyager, and the holes lined up perfectly.
On my 2004 Advantages (UL Kevlar and 2004 carbon/kevlar) they don’t appear to line up exactly. I chose to keep the older style braces in the Advantages.
The old style braces don’t allow on the
water adjustments, hence my change to the sliders, which are easy to adjust. I was out in the wind in the Advantage last summer and couldn’t adjust my brace after adjusting my seat.
Of course, the best solution in the seat/brace assembly that move as a unit.
I considered bolts, but
was concerned about crushing the foam ribs.
But NOW that you’ve drilled through, …
… the options are limitless, except that the pop-rivets didn’t work. Right now, you could attach bolts to the same thing the pop-rivets are holding - that internal metal plate you mentioned. It would be exactly what you’ve already done, except that you would succeed in making the fasteners snug.
Or maybe you are thinking bolts would be “too tight”. Don’t make them that tight.
The metal plate is toward the innerside
of the foam rib. The head of the bolt on the outside would likely crush through the foam.
The two rivets at the ends of the rails closest to the paddler are tight. The two at the end toward the bow are a little loose, because I couldn’t get the head of the rivet tool close enough to the back side of the rail when 1.5" in from the end of the rail.
I’ll see how it works on my next outing.