Replies

1. 
   BossCrunkReboot | Jan 14, 2020 12:41pm | #1

   Hand plane it, belt sand it, or perhaps hand sand or hand scrape it if the inequities are very slight.

   Check your work frequently with a long straight edge and winding sticks to make sure you aren't working even worse problems in to the top.

   If you're unfamiliar with processing a large tabletop with hand or hand-held power tools, it might be best to see if a millwork shop would flatten it for you. They have large drum sanders that will do the job in less than ten minutes, maybe less than five.

2. 
   Eideann | Jan 14, 2020 12:45pm | #2

   How much of a difference in thickness are we talking here?
   If it's not too much of a difference (1/8 inch or so) you can hand plane it down, but that's going to be a real bear of a job unless it's already close.

   Sometimes the easiest thing to do really is to just start all over. Rip the boards off, joint and plane them to a consistent thickness and glue it back up. Unless it's already close, then this is going to be the easiest thing to do. It may not sound like it, but it's probably the fastest too... Unless there is a shop in your area that has access do a really big planer or drum sander, those are really the only two options that I can see.

3. 
   joeleonetti | Jan 14, 2020 01:23pm | #3

   The first paragraph by CESStanford is how I would go about solving it myself depending on what kind of differences we are talking about.

4. 
   _mj_ | Jan 14, 2020 02:10pm | #4

   Sounds like a single rip will get you down to a size that will go through a lunchbox planer. Once it is glued back together add battens underneath to hold it flat.

5. 
   mikaol | Jan 15, 2020 10:08am | #5

   Thank you. Good ideas all.
   Mikaol

6. 
   mikaol | Jan 18, 2020 04:56pm | #6

   Hey,
   Thanks again for all the good advice but I stumbled upon 1 way that eventually worked.
   Since all tabletops have a top and bottom, something I figured out all by myself, here's my solution. As the differences were no more than 1/8" between boards, I used a belt sander. Starting with 50 grit I sanded the boards to the thickness of the thinnest board and smoothed down until I got to steel wool for the finest finish from there. It came out well but didn't satisfy me. My opinion: no matter how beautifully a project comes out, a woodworker will always find a minute flaw only he or she can see.
   Anyhow, I flipped the top over and took out my trusty electric hand plane & planed the boards again to the thickness of the thinnest board. Once all the sanding was done, that side, too, came out well.
   Now I have a different problem, of sorts. Which side to make the outside.
   So again, thanks for the help, else I wouldn't have taken the time to think it through.
   Be well all,
   Mikaol (pronounced like Mikhail)

7. 
   ptl027 | Jan 18, 2020 11:49pm | #7

   I just flattened a slab 43 inches wide and 90 long with a router and shop made sled. It was easy and came out surprisingly awesome. Also, I’ve flattened about a dozen slabs using hand planes. It’s pretty quick if you have a scrub plane, jointer plane and a number 4 smoothing plane. It’s a really satisfying experience!

   
8. 
   forrestb | Jan 19, 2020 11:42am | #8

   Ripping it so it will fit your planer (after jointing) is a good idea. Battens after re-glue will help but with that many different species of wood I would get the customer to sign a disclaimer that it might warp again!