Ideas That Work: Sealing Conduits With Bags, Improvising Wire Numbering and More

Every month, Jack Pullizzi picks the top four Ideas That Work submitted by you, ELECTRICAL CONTRACTOR readers. These ideas can't be found in any code or guidebook and are only learned or devised through years of experience and thinking, "There's got to be a better way to do this!" Please remember, the ideas presented in this article are for consideration only. Before using such ideas, make sure codes and safety standards have been fully adhered to. Now, without further ado, here are this issue's Ideas That Work!

Setting up easy removal
When sealing the ends of conduits that come from outdoors to indoors or any temperature change, instead of using duct seal, I stuff a plastic shopping bag into the pipe with the opening just sticking out. I stick the nozzle of my spray foam can into the bag and fill a good amount of it. I tie the bag in a knot and push it into the pipe. The foam expands in the bag and surrounds the wires that are in it. That way, if there is ever a need to remove the wire, the bag will slide right out with the wire.

Colin Boone
IBEW Local No. 7
Granby, Mass.

Catching flak
When hole sawing into control panels or enclosures that contain sensitive equipment, I duct tape or wedge a piece of 2-inch foam insulation board into the area underneath. It catches the metal plug, filings and burrs created when you cut through the enclosure. You can clean off the top without worrying about metal debris getting into any sensitive equipment.

Mike Kelly
Saco, Maine

Punching holes
Most electricians have a cordless impact driver these days. Everyone should have a knockout set of some kind. If your knockout set uses a 1-inch bolt, try a 1-inch impact socket with your cordless impact driver. I punched a 2-inch hole with slug buster knockouts in a very heavy panelboard in just 30 seconds with a ¼-inch impact driver. I punched a 1-inch hole in a J-box in 15 seconds. I have also used my ½-inch air impact with 4-inch knockouts when I had an air compressor available. It was faster than getting my hydraulic knockout set out.

Vaughn sudrala
Rapid City, S.D.

Making more low wire numbers
Have you ever run out of low numbers in a wire number book? Using a Sharpie, mark out the number you don’t need on higher numbers, and you have your own low numbers.

Allen Aab
IBEW Local No. 68

Loveland, Colo

IF YOU HAVE AN IDEA that has saved you time or money on the job, ELECTRICAL CONTRACTOR readers would like to hear about it. Be sure to include a good photo of your idea—hand sketches are often hard to interpret. Note that some ideas are submitted by more than one person. In these cases, the one that is more clearly written and includes a photo is given precedence. Send your letter and photo to Jack Pullizzi, Ideas Editor, ELECTRICAL CONTRACTOR, 3 Bethesda Metro Center, Suite 1100, Bethesda, MD 20814-5372, email, or use the online submission tool at

CASH PRIZE FOR WINNING IDEAS Each published author in “Ideas That Work” receives a $50 American Express gift card from ELECTRICAL CONTRACTOR.

DISCLAIMER: The ideas presented in this article are for consideration only. Before using such ideas, make sure codes and safety issues have been fully adhered to. ELECTRICAL CONTRACTOR magazine disclaims any liability from your use of these or any other ideas. ELECTRICAL CONTRACTOR reserves the right to reprint the words herein at its discretion.

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