if there's one thing that's popular in the woodworking World these days it's a good old myth busting video some of these of course are complete nonsense but this myth is real and I'd guess that 90 or more of you have fallen for this I once did myself because almost every book or magazine I read early on as a woodworker told me that flat panels such as table tops and cabinet tops will warp uncontrollably if you don't cut them up into narrower pieces and then flip every other board to alternate the end grain and then glue them back together this is a myth I don't know when it started but if you look at surviving furniture from 100 years ago or earlier you'll find that some tops have alternating growth rings others don't in both cases some of those tops are going to be warped and some of them aren't that's because all wood warps under the right conditions alternating growth rings can't stop that it can only change how that warpage is Manifest down the road the only effective way to manage warping is through proper joinery and proper care for the piece over time so let me explain wood is always swelling and shrinking in an effort to maintain equilibrium with the humidity in the air around it apply a finish but it's only going to slow these changes a bit it's not going to stop them if one side of the board is significantly damper than the other the board is going to cop toward that dry side but what is most common in Furniture that's stored in today's climate-controlled homes is both sides of the board absorb moisture evenly from the air around it and the result is a cupping away from the center of the tree or opposite the curve of the growth rings over time these cycles of swelling in the winter and shrinking in the summer can cause surface fibers on the cupped side to become permanently compressed and then the board never flattens again because of this many fear that if you build a table from a solid slab of wood you might eventually end up with a big potato chip shaped top so they'll cut that slab into strips or they may just opt to make it up from several narrower boards in the first place and then they alternate the direction of the growth rings so they can glue up what they think is a more stable panel the idea is that while each of those boards May cup individually they'll do so in alternating Direction so instead of a big potato chip you might end up with a wavy washboard surface that while exaggerated in this drawing will be less noticeable overall theoretically this is true the worst case scenario for a panel made from alternating strips is less dramatic than the worst case scenario for a single wide board but the fallacy is that either of those worst case scenarios are inevitable they aren't you can actually stop a panel from warping not by how you Orient the growth rings but how you construct the project itself consider a cabinet top made from a single slab or from narrower boards with the growth rings all facing in the same direction if it cups you know which way it's going to curve opposite the direction of those growth rings so you can use that predictability to your advantage by orienting the board with the growth rings curving upward so that any cup will be downward that'll Force the edges tighter against the frame with only the center of the panel Rising now it will only take an anchor point at each end of the center to hold that panel flat and by anchoring at the center the rest of the panel can still grow wider or Shrink narrower as the wood continues to move naturally incidentally the closer you get to the center of a tree the less sapwood you're likely to see especially in Dark Woods like Walnut and Cherry so boards in this orientation with the growth rings curving upward toward the show face will usually look better on the finished project and that's the real downside of alternating growth rings you lose control of the panel's final appearance but by using the joinery to prevent warping you're free to choose is the most attractive side of each board on your panel if the most attractive panel results in a mix of ring directions well you do lose some of that predictability when it comes to potential warpage so you may need multiple anchor points to keep that panel flat in that case you'd want to use a special type of Fastener such as a figure eight or the old slot and button joinery that will hold the panel down while still allowing it to expand and contract in width on that frame what about a large table top that can be that can't be fully secured to a sturdy frame that's what breadboard ends are for these attach to the ends of your panels in such a way that they keep them flat while still allowing them to expand and contract in width the point is the proper joinery is the key to preventing warping if you build your project correctly you don't need to alternate the growth rings on your tabletops and instead you can concentrate on arranging the boards in the most attractive way if you'd like to learn more about wood movement and how it affects how we work with wood I'm going to put some more links to some videos that I made before on that subject below this one you want to see something else really interesting we use blade guards and push sticks and safety glasses and hearing protection to keep us safe because we want to enjoy this craft for many years to come but what about our lungs I like Trends stealth masks because they have bodies that fully seal on my face this is important to me because a leaky mask is a useless mask the original stealth features a compact size easily adjustable dual straps for a proper fit on your face a downward facing exhale valve that won't fog your glasses and replaceable n100 filters I switched to Trend stealth masks for my Dusty work a couple years ago because they offered the advanced protection of a larger canister respirator in a less cumbersome size that's comfortable to wear all day long check them out at the link below the video
