Tip #17
Disc Sanding (continued)
Click here for a printer friendly version of Tip-
Pg. 1-4, Pg 5-8, Pg 9-11, Pg 12-14

End Grain Sanding

End grain is harder to sand than any other surface, but the Mark V in the disc sander mode makes short work of this chore. You can also use the disc sander to sand workpieces to precisely the same length.

General End Grain Sanding
To sand end grain, position the worktable no farther than 1/16" away from the disc (if you're not using the quill feed) or 1/2" (if you are using the quill feed). Adjust the table height so that the under-side of the table just clears the dust chute and the table is slightly above the center of the disc. When selecting the speed, keep in mind that you want to run the sanding disc a little slower than you would for other types of sanding because end grain will burn easily.

Use the miter gauge to align the workpiece with the disc. Check that the miter gauge is square to the disc, and mount it in the left table slot, closest to the disc. Position the gauge so it will guide the workpiece against the down-ward motion side of the disc; then lock the miter gauge in the slot.

Make a five-point check. If you plan to feed the stock into the disc, all five locks--power plant, carriage, table height, table tilt and quill--should be secure. If you want to use the quill to feed the disc into the stock, the quill lock should be loose. Stand to the right or left of the sanding disc. Turn on the Mark V and let the disc get up to speed.

If you're feeding the workpiece into the disc, place it against the face of the miter gauge and carefully feed it toward the disc until it lightly contacts the abrasive. Hold it there a few seconds, back it out, then feed it forward again. This back-and-forth motion will keep the end grain from heating up and burning. Repeat until the end grain is completely smooth.

Figure 17-4 . When using the quill feed, move the disc in and out as shown. Don't let the stock contact the abrasive for more than a few seconds at a time.

If you feed the disc into the workpiece, use the quill feed to advance the disc until it lightly contacts the workpiece (Figure 17-4). Let it stay there a few seconds, back it off, and feed it forward again. Once again, a back-and-forth motion helps prevent burning. Repeat until the end grain is smooth. As you work, don't press the workpiece and abrasive together too hard. Heavy pressure will cause the sandpaper to “load up” with sawdust and pitch. It will also increase the likelihood of burning. A light, momentary pressure is all that's needed.

Sanding to Exact Length
If you need to sand a number of boards to precisely the same length, use the rip fence mounted to the worktable or the extension table as a backstop. Position the backstop so that it will hold the end of the workpiece about 1/4" away from the sanding disc when the quill is completely retracted.

Figure 17-5 . To sand boards to exact lengths, use the quill feed and set the feed sop to stop the disc where you want to finish sanding.

Set the depth control to halt the disc where you want to stop sanding. To do this easily, use a board that you've already sanded or scrap wood that you've cut off at the desired length (Figure 17-5).

Position the workpiece on the table, against the miter gauge and the rip fence, so that it overhangs the table slightly. Be sure the workpiece doesn't contact the sanding disc. Then make a five-point check. Four of the locks--power plant, carriage, table height, table tilt--should be secure. The quill lock should be loose. If the workpiece is long, use a miter gauge extension for more support.

Stand to one side or the other of the sanding disc. Squeeze the safety grip with one hand and turn on the Mark V. Let the disc get up to running speed; then, with the other hand, feed the disc forward slowly with the quill until it just contacts the workpiece.

Figure 17-6. Sand one end of the board until it's smooth; then turn the board as shown and sand the other end until the depth control stops the sanding disc.

Advance the disc, back it off, then advance it again, lightly sanding the workpiece. Once again, light pressure is all that's needed. Don't extend the quill all the way at this time; just sand until the first end is smooth. When it is smooth, turn the board and sand the other end (Figure 17-6). This time, advance the disc until the depth control stops it.

Repeat this procedure as needed with the other boards you have to sand. When finished, they will all be exactly the same length.

Continue to Edge Sanding
Back to Disc Sander Speeds