On sanding tabletops

In particular, the curly maple kind. This page picks up right after using a router sled to level both sides of the tabletop, and assumes the table top itself is still fastened in the router sled grid.

Start at 80 grit, making sure that you have eliminated any cross grain tearout. I thought that the wetsanding later would fill in the tearout, I was wrong. Wetsanding will only fill in the pores of an open grained wood like oak. Use an orbital 1/2 sheet sander. Don't use a belt sander, as it leaves bandmarks that persist and show up much later, when it is far too late to fix it. Don't use a 1/4 sheet sander, it isn't large enough to make sure that it is flattening the table and not introducing peaks and valleys.

Dry sand at 120

Start wetsanding at 150. I used a manual jig that held an entire sheet of sandpaper. This worked well, in that careful preparation of the surface in the earlier steps meant there wasn't much to do. Well, in theory, that would have been true. In fact, I had to spend about 2 hours on this step, removing the tearout that was left over from the first step. And in the end, resorted to scraping a few last stubborn sections.

Next, wetsanding the following grits:

• 180

• 220

• 320

• 400

• 600

• 1000

• 1200

and then finishing with the car buffer using "ultra high grit", whatever that really is.

In general, I was wetsanding with a lubricant mixture of about 50% paint thinner and varnish. Sometimes, when I was more concerned about removing the wood, like for the 150 grit step, I'd resort to adding more paint thinner. That has the disadvantage of removing existing finish, but the advantage of removing more wood, and skipping a cleanup step.

Wetsanding procedure

• make sure the fan is on and the windows are open

• drizzle lubricant over the surface

• smear it out using the sander

• start the sander, or if by hand, then 20 strokes per section

• repeat twice

• wipe off the excess lubricant/sawdust slurry with a rag

• wipe it off again with another clean rag

• turn off the lights and look at it from an angle to make sure you got all the spots, and assess any flaws

  • repeat about 4 times per grit level

You are both smoothing the wood and building up a thin layer of finish each time.

Fig 1. Wetsanding at 150 grit with the hand sander.

Fig 2. Result of above (finished to 180 grit)

Fig 3. Final result