Tips, tricks, hints and more

Dec 1, 2008 12:00 PM, By John Landry, CSRE

Avoid getting stuck

Many times important supplies go bad on the shelf, especially adhesives and sealants. How often have you gone to use a tube of silicone sealant only to find it dried hard in the tube? Or someone put the top of the two-part epoxy on backward so the hardener made both parts rock hard? It is wasteful to have to buy a new tube of either compound every time you need to make a simple repair.

One method of keeping silicone sealant from drying out was suggested by my colleague Rodney here at CBS. When you are finished using the tube, squeeze a little of the goop out so some runs out the top. Then put on the cap, squeezing a little more out as you tighten it or snap it in place. A ball of hardened sealant will form inside the cap which will prevent the rest of the tube from hardening. And the next time the cap is removed the hardened sealant will stick to the cap and pull out of the tip of the tube neatly so you won’t need to find a long nail, wire or 6″ greenie to dig the tip clean.

Clear expoy is a versatile repair tool but is never used in a large quantity. For this reason, many companies sell it in little single-use packets that are easier to use and last longer on the shelf. One brand name is Hardman Double Bubble available from McMaster-Carr for about $1 per pack (Stock # 7538A11 for quick set; #7538A33 for wet surface patching).

Another item that often goes bad on the shelf is spray paint made useless because the nozzle gets clogged with paint from the last use. Make it a habit after using a spray paint can to turn the can upside down in a trash can and press the nozzle in. Paint will not flow in this position but the propellant gas will clear any paint left out of the nozzle. If someone has forgotten to do this, often a clogged nozzle can be cleared by pulling it off the can and soaking it in either turpentine or mineral spirits. However, sometimes the clog is below the plastic nozzle, in which case the can is now trash.

Clean cut

Cutting and drilling tools dull quickly with heavy use. Saws, drill bits and punches often require more effort and time to use when dull. A common method of preventing this is to put a drop of oil on the surface of a drill bit. The same thing can also be done with saw blades, center punches and other cutting tools. A light spray of WD-40 can often be effective. For tougher materials such as steel or galvanized iron, a tapping oil (such as Moly-Dee, Colco or Tap Magic) is more effective. For coarse sawing, a paraffin-based stick lubricant is best (McMaster part #1009K22; also sold as Do-All Toolsaver).

A recent project of mine required cutting a circular piece for retrofitting a speaker into an opening. The new speaker did not have a round basket, hence the mounting holes in the metal panel would not line up with the old ones and re-drilling was not an option. This piece would resemble a large letter �O� but one challenge immediately became obvious: how to find the center of the piece. After making a mess of the first attempt, I was reminded by another colleague of a simple method of finding the center of a circle: Use a compass, set to the length of the radius of the circle, and pick three points on the edge of the circle and draw an arc through the circle to the far edge. The point where all three arcs intersect will be the exact center of the circle (assuming the outside edge is perfectly round). I was able to cut the two round parts, and the new speaker (as well as a nice, new grille) is in place, working fine. Who says high school geometry is useless?

Landry is an audio maintenance engineer at CBS Radio/Westwood One, New York.

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