: I am trying to find a better way to sand the inside of canoe and kayak hulls.
: I am working on a "Rob Roy" right now and sanding the inside by
: hand with a foam block with sand paper wrapped around it. This is very
: effective, however, my arms are sure getting tired!!

: I used a Dewalt Random Orbital on the outside and this worked very well, as
: you can "roll" the flat sander to match the curve of the outer
: hull. This totally does not work on the inside.

: Any suggestions on technique and/or tools would be greatly appreciated.

: Stephan

When I built a strip canoe, I used a paint scraper to remove the glue drips but I could not keep it sharp enough to effectively remove wood. I found the Stanley SurForm with the half-round, cheese-grater-type blade to remove the wood to rough shape the inside (and the flat on the outside) to be effective. Still several hours of effort were required. Serious sanding was then necessary to remove the SurForm marks. A round ROS does not work well because you have to tip it to reach into the curves and it is impossible to keep from creating waves in the surface when sander is on edge. I used a quarter-sheet finishing sander with custom shaped pads to much better success. I first cut a piece of one-inch thick styrofoam to the square shape of the sander with a hand pull saw and also rounded two opposite corners with the saw to sort of match the inside curve of the canoe. I then cut sandpaper in half cheating 1/8 inch to provide extra length in the direction of the clamps on the sander and exactly in half the other direction. This allowed me to install the styrofoam between the sandpaper and the sander base with the curved edges adjacent to the sander clamps. As I sanded with the styrofoam pad in place grit got between the sandpaper and the styrofoam and sanded the styrofoam into a curve to perfectly match the curve of the inside of the canoe. Then a spot of glue between sandpaper and the styrofoam tacked the foam in place to prevent it from vibrating out the open sides. This soft, curved base on the sander worked quite well at smoothing those inside corners. The 1/8-inch short pieces of sandpaper were not wasted because they were just long enough to still use in the sander without the styrofoam pad for flat work. When I do the next strip boat project, I will used bead and cove strips and thickness plane the strips all to the exact same thickness to reduce the amount of planing and sanding to fair both sides of hull