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Re-Foam the Case That Protects Your Special Gear

Bill Ruck solved a problem with the help of Ethafoam

Veteran voice actor Don Elliot has been following our discussion of useful tools. He has kept the device that’s shown in the first photo in his tool kit for at least 30 years. Can you identify it? 

One of Don Elliot’s most useful tools. Do you know what it is?

Fix the foam

Engineers of a certain age will remember the black, crusty foam used in electronic equipment transport cases. It was a good choice for a long time, until we realized that it eventually turned to sticky black goo and was difficult to remove.

A friend of San Francisco projects engineer Bill Ruck found a wooden case for a Potomac Instruments FIM-41 Field Intensity Meter. He removed the foam and Bill offered to re-foam the case for him. 

Another friend suggested Ethafoam, a brand of polyethylene foam that is stiffer than the black stuff but soft enough so it won’t scratch anything. It comes in sheets and rolls. Bill purchased his from TAP Plastics and paid $2.50 per linear foot.

Using a piece of plywood as a worktable, Bill cut off segments with a straightedge and a shop knife; although it’s sturdy, the material cuts easily. He then cut these pieces into “blocks” to fit inside the FIM-41 case. 

To cushion the meter properly, Bill needed pieces 1 inch thick, so he laminated two half-inch thicknesses together using 3M Super 77 Spray Glue.

Now it was time to assemble the pieces into the case. After testing the fit of all the pieces, Bill glued them onto the case with the Super 77, starting at the bottom, then progressing to the short sides, and finally, the long sides. He glued a final piece to the top of the equipment case.

If you have one of these cases and want to re-foam it, here are the dimensions:

  • Bottom: 15 x 7-1/2 x 1/2 inches
  • Short Sides: Two pieces, 7-1/2 x 7-1/2 x 1 inches (laminate 1/2-inch pieces together to provide two 1-inch-thick pieces per side)
  • Long Sides: Two pieces, 7-1/2 x 13 x 1 inches (see above)
  • Top: 15 x 7-1/2 x 1/2 inches

Bill purchased three linear feet of Ethafoam and had some left at the end; you probably can get by with two linear feet. 

The FIM-41 now fits snugly in its wooden protective case. 

Bill Weeks’ FIM-41 transport case, freshly re-foamed.

For your production folks

Logic Keyboard introduced its latest innovation at the NAB Show: the Titan keyboard series.

Intended for a person who does professional editing on a Mac, it consists of an aluminum backlit keyboard, featuring dual connectivity for an efficient workflow. 

The keys have various commands imprinted to speed media editing. The one in the photo is for video editing. The company manufactures similar keyboards for Adobe Audition and other popular audio editing systems. The keyboards cost less than $150.

The additional symbols and lettering on Logic Keyboard’s Titan keyboard support professional media editing. The company offers versions for video, audio and graphics work.

Bright idea

Broadcast engineer Paul Sagi shares Cliff Kotchka’s dislike of compact fluorescent lamp bulbs, which Cliff described in a letter to the editor in January. Paul says his CFLs always failed with a bang and flames.

He finds that LED bulbs are not difficult to work with as long as he thinks not in Watts, as with incandescent bulbs, but in Lumens.

Good LED bulbs emit 90 to 100 Lumens per Watt. That’s about five times the efficiency of incandescent bulbs and around twice that of fluorescent bulbs. It’s helpful also to understand the color temperature of LED bulbs, referring to the color of light emitted by an object at a certain temperature. 

An LED bulb with the color of an incandescent bulb has a color temperature of 2700 to 3000K. An LED bulb with the color of daylight has a color temperature of 6000 to 6500K. A color temperature of 6000K is cool white while a color temperature of 6500K is daylight. Daylight LED bulbs are more efficient than warm white LED bulbs.

LED lighting uses half the electricity of fluorescent. Though they cost more, the payback period for Paul was one year. Paul has not had to replace LED bulbs for four years, and the saving of electricity offsets the electricity used by his vented clothes dryer.

(Karl Zuk wrote more about color temperature in the April 24 issue of Radio World.)

Another bright idea

The final photo will help you identify Don’s tool, if that little flashlight bulb didn’t give it away. It’s an inexpensive battery tester. The brighter the bulb, the fresher the battery. Constructed out of solid wire, it can be bent to accommodate most battery terminals. Don’s 30-year-old tester still has the original bulb!

A simple and efficient battery tester that has lived in Don Elliot’s tool bag for 30 years.

Workbench submissions are encouraged and qualify for SBE recertification credit. Email [email protected].

[Read Another Workbench by John Bisset]