Replies

1. 
   oldusty | Sep 09, 2007 06:45pm | #1

      c,

            Is this a rough board or a pre surfaced board ?

              If the board is cupped the wide belt will squish and flatten it while it runs through the sander , but it should sand the surface smooth .

    You would have to remove material from both sides of the board to make it stand alone flat.The problem being the board may be too thin for your work if done that way.

        Unless there are seams where boards are glued together the wide belt will be of little use for making it flat . If a board is thicker on one edge then across the width then yes a wide belt can eliminate the runout .

      Many tops I have made have been run through wide belts and some were not perfectly flat . When you fasten the top to the end table apron or frame from the underside this will keep the cup flat , if the cup will not easily flatten and allow you to fasten it correctly then really don't use that wood .

               On all solid tops imo you should treat the top the same as the bottom as far as the finish goes, give it every chance to be stable .

                good luck              dusty

1. 
   ctsjr | Sep 09, 2007 11:07pm | #2

   Thanks, dusty. I am working on theoreticals here--I want to use one wide board for the tops of the end tables, and was wondering if you could flatten the board using a wide belt sander. You answered my question. Guess I'll need to look into a scrub plane and a straight edge. Tom"Notice that at no time do my fingers leave my hand"

2. 
   [email protected] | Sep 10, 2007 02:17am | #3

   Sometimes you can do wide boards and get them flat.  You will need a good straight edge and some colored pencils. 

   Check for bowing or cupping, and if you have any set the board so the high edges are toward the drum. 

   Mark the surface of the board that will be sanded with random pencil lines, and set the sander to take just a little off.  If you try to hog off a bunch at once it increases the deflection caused by the sander, so a little at a time is best. 

   Make a pass.  That should clean up a little on the edges, but leave the pencil marks in the middle of the board. 

   Mark the areas that were sanded with a different color of pencil and feed the piece back through with out adjusting the height on the machine.  Keep doing this until you can barely see the pencil marks in the area it is sanding before you adjust the height, and then just a little. 

   When you have the whole surface sanded check with the straight edge and it should be flat with a minimum of stock removal.  Now flip the piece over and do the other side. 

   My buddy Bill did it pretty much the same but flipped the board every time he adjusted the depth.  We still argue about who has the better method, and I think that both work equally well, but don't tell him I said so. 

3. 
   knuts | Sep 10, 2007 03:17pm | #4

   I use my hand held belt sander (60 grit) to take off the high corners

4. 
   ted | Sep 11, 2007 04:02am | #5

   been there done that. I use wedges or shims and carpet tape for bowed, cupped or twisted boards and prop the bottom face to keep it from rocking as it goes through the sander. When one surface is flat flip i over take off the shims and sand the other side flat