Common Wood Defects

Wood is far from a stable, consistent material. One of the biggest challenges of woodworking is learning to work within the constraints of a wood's properties. But before you can expect to work within these constraints you must understand them. It is for this reason we present you with the following article, Common Wood Defects.

Wood Features Caused By Effect Solution Defect A bluish gray discoloration on the Mold that grows in Can be cut off, placed Blue Stain woods surface. This warm and moist Discoloration of out of sight, or feature is most area, usually wood. concealed with a dark common in woods like poorly ventilated. stain. Holly, Pine, and Sycamore. Improper storage. Cut in to smaller A curve along the face Usually moisture pieced, even out on a Stock is difficult to Bow of a board that usually evaporation from jointer, or nail (screws work with and cut. runs from end to end. one side and not are better) in place the other. with bow bulging out. Breaks at the end of a Checks or board that run along Can effect the Splits the grain. Checks and strength and Should be cut off or Rapid Drying. splits are usually appearance of the worked around. restricted to the end of board. a board. Warping along the edge from one end to Can be caused by The higher spots can the other. This is most improper drying Can be difficult to be cut away on a Crook common in wood that and storage or the work with. table saw or jointer was cut from the presence of using a special jig. center of the tree near reaction wood. the pith. You can try allowing the board to dry at the Warping along the Stock can be This defect can be same moisture face of a board from difficult to work Cup caused when one content under edge to edge. This with. Trying to board face dries at pressure, rip it into defect is most "force it flat" can a faster rate than smaller pieces on a common of plain-sawn cause cracking the other. table saw, or use a lumber. along the grain. jointer to remove the high spots. This is caused by Can mar the Dead or a dead branch that Should be cut out, appearance of the Loose Knot A dark, usually loose was not fully around, or glued in wood, fall out, knot. integrated into the place and filled with a become loose, or tree before it was wood putty. weaken stock. cut down. Gum, Sap, Accumulations of a or Pitch resinous liquid on the May cause Should either be cut surface or in pockets Injury to the tree. difficulty when off or scraped out and below the surface of finishing. filled. wood. Machine Dark streaks along the Usually caused by Discoloration to Can be sanded off or Burn face of a board. planer blades that the surface. cut down with a are dull or spun on Sometimes the jointer. The depth of a part of the board burn can penetratethe board often for too long. into the board. determines the amount of work needed. Breaks in the wood Improper drying or Should be cut around, Can effect strength Ring Check along the annual damage during place out of sight, or or appearance. growth rings. transport. glued down. May be removed for This was once a appearance Tight Knot A know which is tightly branch that was Does not effect thepurposes. Some integrated into the incorporated into lumber's strength. lumber such as Knotty surrounding wood. the tree as its girth Pine, is highly prized increased. for this feature. Growing Warping in lumber Can be cut into conditions, uneven where the ends twist Can be difficult to shorter boards or the Twist drying or the in opposite directions. work with. high spots can be presence of (Like twisting a towel) removed on a jointer. reaction wood. Cut around worm Wormholes This is caused by Can be used to holes or uses as is for Small holes in the insects boring simulate old or decorative purposes. wood. through the wood. wormy wood. Be sure the insects are dead.