: I sanding my first boat, a Coho, in preparation for varnish. I know the
: objective is uniform, flat white matt. However, I am getting a mottled
: appearance in many areas,where the mottles are apparent low spots. I am
: using a random orbital with1 150 grit. Tried 100, it cuts too quick to the
: cloth for me. With the 150, I do get into the cloth here and there, but
: not bad, but if I keep sanding to get everything white, I start to hit
: more cloth than seems right.

: I tried a test path with varnish on a typical area, and for my purposes (need
: tobet out while the summer is still here,not too concerned about
: perfection_ the finish after even one coat looks great. My concern- will
: the varnish fleck ooff of those low spots that haven't been thoroughly
: roughened? Conversely, I am afraid exposing too much cloth is weakening
: the boat, and may look worse than those low spots. Hand sanding seems to
: be more effective for spot removal after machine sanding the bulk of it,
: but it is very slow going to get everything white.

: Is there something I am missing with the ROS? Fatter pad, different grit?
: Should I relax and varnish,or sand and sand, not worry about all that
: weave exposed?

: Thanks

Rod I am at the same point you are now and I look forward to the answers to you question. I finally started hand sanding using 100 grit on a handled sanding block with a foam base that is sold for sanding patching plaster. It seem to work real well for me. I have some dips that I can't quite reach and so I thought I would give it one more squeegy epoxy coat to help fill the low areas and then let the varnish do the rest of the filling if there is any.

John