I shortened a paddle once by cutting in half at the middle....cut/take off wanted amount to desired length....insert wood dowel that fits tight and inserts about 3 or 4 inches inside the shaft on both sides of cut....set to preferred off-set....wrap in kevlar cloth at the cut seam....used vinylester resin. I guess you could even make it into a breakdown with a kit (I think they used to make such a kit somewhere??) but I found the wood dowel set-up I used was bombproof solid.