Flattening a Cupped Board or Shelf
from Michael Humphries

If you have a wide board that has cupped over a period of time (before you had a chance to assemble it or put any finish or paint on), here's a way to get it flattened. First you have to realize that this movement is a natural occurrence in a wooden board once it is sawn out of a round log or if one side of the board has picked up or given off more moisture than the other side. And that is the solution!

Put the board down on a sheet spread out across the lawn and put the cupped (concave) side down. On a sunny day you will have to watch carefully as the moisture in the grass is absorbed by the underside of the board and the sun dries out the convex side of the board. As the moisture enters the bottom side of the board, the wood swells and expands increasing the width across the bottom of the board. Conversely the topside loses moisture through evaporation to the sun's rays and the wood shrinks becoming narrower across the top of the board. These dimension changes are very small but will have a profound effect on the board and it will become flat. As soon as it is flat, take it inside and sandwich it between two solid stable surfaces like a work bench and a piece of 3/4" plywood. Put a heavy weight, like cans of paint or concrete blocks, evenly across the top and allow the board to relax and dry out evenly for a few weeks.

Ever dent a wooden table top? At some point I think we all have. I used to think that there was no way to repair damage such as this without getting a new top, several years ago I learned this interesting technique.

To complete this repair, you will need a good iron with adjustable heat settings. Also, some water and a few clean rags. Please note that this procedure will work on all wood tops, but it may be damaging to newer woods, and will certainly affect hard finishes. Such as lacquer, varnish, etc. Damage to these finishes, however, can be repaired.

First, fill the dimple of the wood with water. Next, place a wet cloth over the dimple. Gently press an iron onto the wet cloth. Be sure to use a low setting, as you don't want to scald the surface of the wood. Repeat this three or four times. Make sure to keep the cloth and the dimple moist.

Re-Calibrate A Tape Measure

Tape measures are an absolute necessity in the shop. Whether we are in the field taking dimensions, calibrating our machinery, or checking our work for accuracy, a properly calibrated tape measure is a must. If your tape measure is off, it can cause a disaster at any point during the design or construction process.

The metal tab on the end of the tape measure is what controls the calibration. If the tape measure is dropped, or retracted too hard, this metal tab can become bent.

Recalibration is simple. What we have in the shop is a 16 inch piece of steel that is precision cut to size. Our woodworkers routinely check the readings of their tapes against this calibration piece.

Making A Board Longer

Have you ever cut a piece of molding for a mitered joint and cut the angle perfectly, but cut the board's length a little too short? And it was your last piece of molding from the lumber store that is now closed on this your project day? Here's a tip too make the board long enough to make the miter tight with a very small, almost imperceptible visual sacrifice.

Simply take a hand plane, jointer plane or small jointer and plane about 1/16" of an inch (or what ever is required) off the short edge, or inside edge of the molding, i.e. from heel to heel over the length of the board.