Cupped Boards.

beeg · Post by **beeg** » Mon Jun 01, 2009 2:08 pm

What method do you use to flatten a cupped board? I have a 2X6.75X21 that I need to remove some cup from it.

tdubnik · Post by **tdubnik** » Mon Jun 01, 2009 2:27 pm

I have tackeled this a couple of different ways. I will sometimes hand plane if the board is not too big.

Since your board is too wide for the SS jointer, you could rip it, joint it, and then glue it back together.

The last method that I recently used was to make a MDF sled for my planer. I laid the board on the sled with the cupped side up. I then double taped wedges under each side about every 4 to 6 inches until the board was stable. The sled should be longer than your board and have a lip on the end that your board will catch on. Place your board against the lip and feed that side into the planer first. Take very light cuts until you get that side flat. You can then remove your board from the sled and plane the other side normally.

curiousgeorge · Post by **curiousgeorge** » Mon Jun 01, 2009 3:03 pm

Bob,
Three ways in preferred order...
1. Jointer
2. Hand plane
3. Router on ski's

charlese · Post by **charlese** » Mon Jun 01, 2009 4:41 pm

Since your board is 2" thick, you can probably get by using the planer - without a sled - provided there is no twist in it. With the two high edges of the board on the planer bed, remove VERY SLIGHT AMOUNTS OF WOOD less than a 32nd inch in the passes to remove the high center of the cup. After you have a reached a flat side, you can flip the board and plane the other side. Of course, you will end up with a thinner board, depending on the amount of cup.

The reason for VERY LIGHT cuts in the planer is so the machine does not compress the board removing the cup before it is planed. If after the first pass, you see that only a small part of the highest part of the board has been planed off you are doing O.K. and can continue. If you see a major part of the board has been planed off - try another method.

beeg · Post by **beeg** » Wed Jun 03, 2009 1:45 pm

Thanks to all for the info/help.
What I finally did was, I traced the arms for the teddy bear chair on thewood. Then cut that part off and jointed an edge, and used that edge to joint the face. Now it's good to go to resaw it to the 1.5 inches I need it to be. Which will remove the concave section.

tdubnik · Post by **tdubnik** » Wed Jun 03, 2009 1:57 pm

Glad you got it worked out beeg. No matter how many ways there are to do something, it seems there is always "one more".

beeg · Post by **beeg** » Wed Jun 03, 2009 2:59 pm

HAHAHAHA YEAH the ONE MORE isn't the one I thought of.

robinson46176 · Post by **robinson46176** » Wed Jun 03, 2009 5:11 pm

For a good cure you just need to drop it off at a friend of mine's shop and have him run it across his ancient 13" jointer he once showed me he installed in his back room for just such jobs. Of course it would take him at least 30 minutes to get enough stuff moved to get the back room door open.

Then it would take most of a day to move enough stuff around in the back room to get over where he could lay both hands on the jointer.
Then another hour to move all of the stuff that has accumulated on those nice wide tables. The next delay comes when he realizes that he needed another 3 phase box for the 4 head molding unit he built last year and robbed the one off of that jointer...

Are we seeing a pattern here.

beeg · Post by **beeg** » Wed Jun 03, 2009 5:44 pm

[quote="robinson46176"]
Are we seeing a pattern here. ]

Yeah it takes time to get it done.