My artwork requires that I glue up many long boards to each other. I wind up, essentially, making a table top, that I then use as the base of my art. I've made a ton of mistakes along the way and, as such, have slowly carved out a foolproof way of gluing up boards to prevent warping. Here's how you do it: 1. First make sure your boards are straight and true. Plane down the top and bottom faces forst for a uniform thickness. Then use your jointer/planer to plane down the edges to an exact 90 degree angle from the faces. 2. Lay out your boards in the exact position you will glue them. Flip the boards, re-arrange, and try out new formations to make sure you've got them in the order that looks best for your project. Pay attention to grain pattern especially. Sometimes you'll want the grain to run into each other so the seams are nearly invisible. Sometimes you'll want to accentuate the seams. If you can, look at the edges of your boards and try to arrange them so the grain patterns alternate. If the end grain on the first board makes a general "U" pattern, try to place a board right next to it that makes a general "Upside-down U" pattern. In this way, the natural pulling of each board will cancel each other out. 3. Once you have everything in the order you like, mark each board like so: write "edge in pencil along the far left and far right edges of the entire set-up. Then for each seam where a board touches another, mark an "X" on the right edge of the board to the left and then a "O" on the left edge of the board touching the "X"-marked board. Mark each seam in this way, so the right edges of each board is marked "X" and the left edges of each board is marked "O". 4. Take your boards back to your jointer. Set the blade very shallow and run each board edge through through again, but this time, run them through with all the "X" edges facing you and all the "O" facing away. This will ensure that if your jointer fence was not exactly 90 degrees, the offset will be accounted for by alternating the boards going through the planer. 5. You're now ready to glue-up! Glue two boards at a time. If you do more, you're likely to run into trouble. Place two long metal straight edge levels on your work bench. You'll use these to raise your boards during glue-up. Cover the levels with painters tape, because they'll get glue on them and you can easily just change out the tape when this happens. Also cover half the number of clamps you intend to use with painters tape, as well. You only need to cover the part of the clamp stem that will be directly underneath the glued seam. (You'll see.) 6. Glue your board edges, making sure to apply an appropriate amount of glue to EACH edge. Too much will squeeze out of the seam in droves. Too little won't seep out at all. The right amount is to have a small amount seep out, but which is easily wiped off with a paper towel. 7. Place your boards on the levels and alternate your clamps, one over, one under. This will help spread out the pressure, so you don't have all your clamping pressure inadvertently cupping the wood. We're human and won't put the clamps on exactly straight. So this avoids human error issues. :) Now you can see why you'll put painters tape on the underside clamps. Glue on clamps is hard to clean and will rust the metal. 8. When you've got your boards clamped, now use A-clamps to clamp the boards to the metal straight edges. This will further ensure the glue-up is straight and true. Make sure you place the A-clamps at the edges, and directly onto the glued seam. (So make sure you wipe off the seeped out glue before placing the clamp here. 9. Let the wood sit at least 2 hours. Longer if it's cold outside. If you're immediately gluing up more boards, go ahead and do so now. But once you've glued up all your boards, clamp it for about 8-10 hours. Then unclamp everything and let the wood sit for 24 hours. Do not attempt to machine the wood (sand, etc) until you've let it just sit. This gives the glue enough time to fully cure. Fully cured wood glue is stronger than the wood itself in most cases. 10. Enjoy! Do you have any tips to share? I'm always looking for new little tricks to use in the shop. Woodworkers are some of the most inventive people I know!