bowed board

[Mike Steinhilper]

i'm gluing up a panel with 3 7" wide boards. One of the boards is slightly bowed. They are only 1" thick and I don't want to end up less than 3/4" for the table top. I'm afraid I'll lose too much material on the jointer trying to make this board completely flat. Can I use the slightly bowed board in the middle of the panel? Or do I need to start over with a new board?

[Lee Schierer]

You could rip the bowed 7" board down the middle, joint and plane the two pieces to get close to your final thickness, then joint the cut edges and glue it back up to make a full width board and finish planing it down to final size. the cut in the middle should be pretty near invisible.

[Mike Steinhilper]

Lee, I'm sure what you said makes sense, but I'm a little dumber than the average joe. Can you elaborate?

[Thom Sturgill]

Let me try explaining:
If we are talking about bowing along the length of the board and the bow is say 1/4", place the board so that the mid point and one end is on a table . Whats the bow on that segment? It should be much less than before. If the bow is fairly even along the end and not concentrated at one end then cutting and flattening should do the trick.

If the bowing is still too extreme when you check the half length, try 1/3 the length, or if its a LONG table maybe even 1/4 the length.

If half lengths work, cut the board in half so that you have two boards with a very slight bow. You can flatten them (jointer, then thickness plane) without losing anywhere near as much thickness. Then square the ends and do the glue up with two shorter boards. You can do something similar to correct cupping across the width.

[Lee Schierer]

Lee, I'm sure what you said makes sense, but I'm a little dumber than the average joe. Can you elaborate? At least one board is bowed across the width right (called cupping). If so then rip that board into two 3.5" wide pieces. Joint one face to get it flat and then plane the other side to say 7/8" thick. Then joint the twoedges where you cut the board in half so they are perpendicular to the newly faced surfaces, Glue the two 3.5" wide pieces back together and make a single 7" wide board.

If the board is bowed along its length then you may be able to place it in the middle of a larger panel and it will stay straight. You would plane the baord to 3/4" thickness and then spend time while doing the panel gllue up to pull it into alignment with the outside pieces. Basically if you can push the board into a flat condition easily by hand then it will probably stay flat in the glue up.

[Mike Steinhilper]

Got it... i think the 'rip' part got me confused. ripping would be for cupping right? so for bowing along the length, crosscut the board -- like sawing through the top of the St. Louis arch? makes sense. thanks!

[Chris Padilla]

Let's see if a picture (http://www.sawmillcreek.org/showpost.php?p=74894&postcount=5) is worth a thousand words.