Warped Boards

[Brent]

I was wondering how you can joing to boards (2 1X10's) together using pocket holes with the finished product being warped? The screws seam to pull the joining piece up a bit?  I have tried aligning the grain of the two peices of wood in the opposite direction.... thoughts?

[james wilhelm]

Brent , I have joined a lot of 1 " x 10"  boards together with Kreg screws and also biscuits with glue on both and have had good luck with both !!!  I use a clamp table that I built on my bench , I used 4 T tracks  four foot long and screwed them to the bench , then I made up two sets of clamp boards , different sizes  out of 1" x 2" oak  with a hole on each end , then I use t bolts in the track to clamp them over night  and the stay  straight !!!  I have some pics. , but will have to find them in my files and will post them , hope this helps , have a good day , JIM !!!

[Don Foley]

Brent,

If you mean the two boards are misaligned after joining them with pocket hole screws, I'd say you need to clamp them together more securely.  consider using some clamping cauls to keep the boards aligned.

If, on the other hand, you mean the edges are aligned but the resulting panel is not flat you have two things to consider.  The first is, are the boards jointed to insure a right angle between the face and the glued edge.  If they are its possible with the pocket screws all being on the same side of the boards (I assume on the backside) they are bowing the joint slightly; since all the clamping pressure is on the same side.  This is why its recommended when using bar clamps to glue up boards the clamps are alternated above and below the panel being glued.  Once again the use of clamping cauls could help.

Hope this helps, Don

ps. If your gluing 1x10's purchased from a home center, do not assume the edge joint is a true 90 degrees.

[Ken Darga]

Wide boards, purchased from a lumber facility, with have some warpage, twisting, and cupping.

When a board is cupped, the finished edge WILL NOT be a perfect 90 degrees in relationship to its overall width.

It's better to obtain lumber from facility, where the material is stored flat.

(Lumber stored vertically, or at a slant, it will develop a warpage in a short time).

Before proceeding, check the boards flatness using a accurate metal "straight edge".

An aluminum angle 1/4" x 2 x 2 x 36 is a good choice.  It can also be used for other tasks---such as clamping, a straight-edge for hand routing, and the like. 

A thicker straight edge of 1/4" is better than using a thin flexible scale.

(I use a metal straight edge that is 1/4" thick and a width of 2-3" for accurate readings, as well as the 1/4" alum angle, as described above).

I obtain best results edge joining boards, in the flat, using narrower strips, to reduce/eliminate "cupping".

Strips of 2-3", with a max of 4".

Narrower strips can be cut from wider boards.  

After cutting, store the boards "FLAT".

When edge joining, alternate the grain pattern UP and the adjacent board DOWN. for best results.

Lay the pieces, "side-by-side", orientate the best side "UP", to get the desired results for grain pattern matching.

Once laid out to your liking, mark the "top-side" with chalk or pencil, so as to keep track of where the boards are to be positioned in the final assembly.

Chalk and/or pencil clean up easily, using mineral spirits---allow to dry, then followed by light sanding, before proceeding to finishing.

[Brent]

Thanks for your answers, they were helpful!