Tape Measure Maintenance
by Damien Andrews
Perhaps the article should have been titled "Retractable Tape Measure Maintenance" or "Automatic Tape Measure Maintenance." Because we're going to be highlighting a foible of retractable measuring tapes, putting forth appropriate cautions, and showing how to help stay ahead of the problem.
The tape measure is one of the most frequently used tools in the carpenter's tool bag – if not THE most frequently used tool. The tape measure comes out even before the carpenter's job really gets going – during the planning and drawing phase. Whether you're going to put up a new stud wall, make a brace for a shelf, hang a picture or cut inlays for a table you're making, you'll likely draw the measuring tape from your toolbox before anything else. The committed do-it-yourselfer, like the professional carpenter, will have several tape measures in his toolbox. I keep the following tape measures in my toolbox: a 6' retractable tape measure; a 16' retractable tape measure; a 25' retractable tape measure; a folding carpenter's ruler. I also have three, 100' tape measures – which are invaluable when squaring large projects such as deck and foundations.
Retractable tape measure, auto tape measure and tape measure have all become terms referring to the variety of measuring device that can be unwound from out of a small case. The actual ruler portion of the tape measure can then either be locked into a specific position, or allowed to automatically retract itself back into the case. They're quite ingenious, really – convenient, handy and lightweight. But they do have one characteristic which can allow for a problem.
Retractable tape measures have a small, 90° angled piece of metal attached to the very end. This marvelous little piece of metal allows the carpenter to accurately measure all alone. The angled metal is hooked over a board and the tape measure is extended. If the angled metal was not present, then the carpenter would have to figure a way to get the end of the measuring tape to stay at the precise end of the board being measured. After the measurement is taken, the carpenter shakes the measuring tape, which causes the metal "L" to come loose and allows the internal mechanism of the measuring tape to retract the extended portion of the ruler. It's a real time saver!
The problem with automatic tape measures is that helpful, handy 90° metal "L". It has been attached to the ruler, usually with rivets, and it comes loose. Not so loose that it will fall off, and not so loose that it won't hold tightly to a board while measuring. But definitely loose enough to affect a measurement – in fact, to affect every measurement taken with that particular tape measure. And that's just no good. Let's have a look at a measuring tape that has a faulty "L", and discuss how to repair the problem.
In the left side (A) of Diagram 1 the "L" is pulled away from the measuring tape, the way it would be if it were hooked on a board's edge. The right side (B) of the same diagram shows the "L" pushed back into where it belongs. The red arrows point out places where the difference is most easily seen. This variation amounts to roughly 1/16". Now, while 1/16" will not really have an adverse impact on stud lengths, it will most definitely play havoc with many projects – including the installation of wall moldings.
To correct this problem, you'll want a ball pean hammer and a flat punch that is slightly larger in diameter than the diameter of the rivets used to attach the "L" to the ruler on your measuring tape. Now:
Be sure to check your measuring tapes often, to ensure that they are measuring correctly. And always remember the Carpenter's Golden Rule: measure twice, cut once…
- Use cellophane tape to secure the "L" to the ruler in its proper location.
- Put one side of the rivets on a solid steel surface – the anvil side of your workbench vise is ideal for this.
- Center the appropriately sized punch on the upside of the rivets. Wearing eye protection, strike the punch with the ball pean hammer quite firmly. Repeat this process for each rivet in your measuring tape.