Gluing Warped Wood

Support

• Use supports when laminating two pieces of wood together. Sawhorses allow you to apply equal pressure to both sides of the wood. Because they have straight beams that aid in leveling the two pieces together, you can place clamps under, over and on both sides of the wood without interference. If you're gluing warped lumber together, run the grain of the wood parallel to the beam of the sawhorses. If you're gluing wider pieces of warped plywood or particleboard together, use multiple sawhorses to support the sheets in the middle or where the warp is the most extreme.

Warps

• Place warped wood together with the warps facing away from each other to form a pocket between them in the middle. If only one piece is warped, place the good piece on the bottom and place the warped piece on top with the warp rising up from the middle. Check the pieces before adding glue to determine which side needs the glue. If you can't tell which direction the warp is going, place the pieces on a flat surface. The warp -- also known as the crown -- will become obvious. If the wood is twisted and warped in different directions, place the best piece of wood on the bottom, with the more severely warped piece on top.

Glue

• Apply glue to the sides of warped wood that will make contact. Use a brush to spread it evenly. Use powdered resin glue if the project is large. Mix this type of glue with water and spread it on for larger pieces of warped wood. Resin glue takes hours to dry and allows you enough time to coat both pieces and position them correctly. Use white wood glue if you need something you can brush on in a few minutes; position and add the clamps before it gets tacky. If you've got multiple pieces that you need to glue together, stack them on top of each other and use resin glue to prolong drying time.

Clamps and Braces

• Place as many clamps as possible around the perimeter of the two pieces. If the pieces of wood are flush with the ends of the sawhorses, place clamps under the sawhorses. Bar clamps work best because they are capable of applying the most pressure, but you can use C-clamps or any other smaller clamp if that's all you have available. Any clamp is fine if you can compress both pieces together until glue oozes out between the joints in the wood. Use two-by-four studs across the top and bottom on larger pieces of wood. Place them on their edges, directly opposite each other on the top and bottom. Place clamps on the studs and tighten them. If you can't get adequate pressure in the middle to smash the warp flat, drive wedges under the studs above the warp to increase the pressure. Place clamps over, under or across the wood if the two pieces slip sideways. Allow the clamps to remain on the wood overnight before removing them.