Bottom Job / Barrier Coat
Years ago I had multiple lays of old bottom paint that I wasn''t looking forward to taking off. Too much like work! I used a pressure washer with a sand pick-up. The sand pick-up is simply a tube (aluminum with a hose attached) that I stuck in a bag of sand. The other end of the hose was attached to a fitting at the end of the pressure washer wand. The venturi effect of high pressure water screaming by the hose created a vacume, sucking the sand up and blasting it onto the surface. Worked very well. A local sand company should be able to tell you what type of sand you should use (75 lb bags). No dust, very little risk of doing damage to the bottom. The finished surface is perfect for the Interlux Interprotect system of epoxy coating.
If that''s not something you want to try, here''s another idea that I figured out due to my lack of willingness to hold a sander against the bottom of my boat for hours at a time. I had to sand but couldn''t hold the sander very long (weigh of the sander plus the pressure to apply it to do any good). I purchased a pole sander (used for drywall applications) with a large metal head and metal universal joint. Not the plastic ones, they won''t last. I took my large power sander and nylon strapped it to the sanding pad. The I used a couple of wooden blocks on the ground under the boat where I wanted to sand. Put a 2 x 6 plank about 8 ft long on the blocks. Placed the pole of the pole sander on the middle of the plank which pushed the sander against the bottom of the boat! The flexibility of the plank allowed for applying the right amount of pressure against the hull. All I had to do was "drive" the sander along the bottom where I wanted to sand. It worked great!