: Hi,
: I am sanding the deck with a fairing board ("long board"), grain
: 60. Is there a better way to "see" the remaining low spots?
: (coloring, dusting, marking, light)
: -Joachim-

If you are sanding the wood, just sand away with the board. You may want to use a plane or a Stanley SurForm to knock off the highs first. . If you do the fairing with a board the smooth surface will show that you have sanded all of the surface. If you mix ROS, loose sandpaper and small hand blocks with the same grit as the fairing board all you have to go by is a visual check bouncing light off the surface. If you stick to the fairing board for the final shaping and final grit you can see the lows better and even feel the coarse unsanded spots. More effort for a better product.

When sanding the epoxy, you want to obtain a final wave free surface. It is also a harder material that requires more sanding. So I put on three fill coats then ROS sand and then fairing-board sand. At this point I will be touching glass in a few spots. I add two more fill coats and then only use the fairing board. Any low spots will remain shiny until the surrounding area is sanded deep enough. If you use a ROS at this point you will concentrate sanding on the low shiny spot and make a bigger low spot. I will probably again touch the glass in a couple spots, so I add a final fill coat and then only hand sand it with a ¼ inch thick rubber sand block with 220 grit. I understand that epoxy exposed by sanding will eventually develop white specks even through the varnish so it is important not to sand through the final coat. This process takes more time because of three epoxy cure cycles, but I have not found a better way to eliminate the ROS waves in the surface. I look at kayak building as a separate hobby from paddling and I have a kayak to paddle so I don't mid the extra time.

The same degree of fairness cannot be obtained on S&G boats unless the epoxy is really built up over the glass. The plywood has its owns waviness that cannot be removed by sanding the wood.

Vaclav's marker method is similar to sanding away the shiny spots. I would like to hear how others avoid the waves from power sanders.