on hardwood, following planing I don't start sanding
: with a grit more corse than 100. Fairing is a bit of a different matter,
: but softwood is really soft, so go easy. 60 grit is brutal, and 80 isn't
: much better. It's easier to sand a little longer with a finer grit.
: There's a lot less chance of making a mess.

Leveling wood produces a uniform flat or fair surface. Smoothing refines the surface in preparation for finishing.

Sanding a stripper is very different than sanding furniture made of flat wood that has been thickness planed. Wood used to build furniture has been squared and leveled with the jointer and thickness planer. Woodworkers who use planed wood rarely use a grit coarser than 80 because sanding is only needed to remove the machine marks left by the planer to prepare for a finish.

A stripper requires leveling using sandpaper to conform to the curving surfaces.
The joint of each strip will be slightly high, even if aligned perfectly. These joints and any other irregularities must be leveled into a fair uniform surface.
60 grit used on a ROS is ideal for this purpose. 60 grit used with the proper full flat surface of the ROS held against the wood will remove material fast and uniformly producing a fair surface. 60 grit will clog less and cut glue lines quickly.

80 grit or higher will not do this, and is not intended for leveling. If 80 grit is used for leveling a stripper it will not cut and level quickly. 80 grit will clog and you will become impatient and have to use an edge of the ROS disk to "erase" stubborn irregularities or glue spots which will produce a surface that is NOT FAIR.

: - when you sand with your orbital sander, don't sand in one spot to get out
: the scratches or you'll create a low spot. Keep it moving over a large
: area until it's gone.

Exactly! This is why 60 grit is needed to level the surface.

Then wet the surfaces down with a soaking wet sponge. This will raise the grain and greatly reduce the cut marks made by the 60 grit. If you don't soak the wood down you will have a lot of sanding to remove the 60 grit cut marks.

This is very soft wood!!! Next you can jump to 120 grit. After sanding with 120 wet the wood,and look carefully for scratches, mark with a pencil. I sand to 220 grit, then varnish.

: - remember that sandpaper is a cutting tool, just like a chisel or a plane.
: Don't be shy about ditching your sandpaper the second it seems like it's
: not cutting as well as when you started. If you don't, when you work with
: softwood it can cause a lot of problems. It won't cut the harder annual
: rings as well and you'll end up with bumps and hollows, and it can
: compress the wood instead of cut it. With softwood it is important to
: swell the wood with water between grits in case you have compressed
: anything.

I agree totally.

: - when you're done test to see if you have gotten everything how you want it
: by wiping it with mineral spirits.

I use nothing but water. Many solvents are reclaimed and contain contaminants that can screw up your epoxy!

Shine the brightest light you can find
: at your project right at the same level as the project almost parallel to
: the surface you're checking and look at it at the opposite angle toward
: the light.

Yes, and do the same as you varnish.

: - don't over-sand. On softwood 120 is probably fine. At a commercial shop
: where I worked we never went over 120 even on hardwood, and things looked
: great even with thin finishes, not epoxy.

That may be okay, but if you build a few boats and see one where the wood has been sanded to 220 you will see how much more luminous the wood looks.

All the best,
Rob