Builders’ Tip: How to Revitalize a Finishing Trowel

During my years of finishing concrete in Alaska, Michigan and Wisconsin, I’ve noticed a universal bad habit among fellow concrete finishers — they use trowels with edges that are chipped, jagged and razor sharp.

Cement masons are usually proud of their tools and will tell you the trowels are “broken in just right.” Unfortunately, no matter how talented the finisher, he or she can’t do a great job with a less-than-perfect trowel.

Not only are out-of-tune trowels counterproductive, they also can be downright dangerous. Finishers who have never cut themselves on a sharp trowel are as rare as carpenters who have never hit themselves with a hammer.

Instead of buying new trowels when mine become chipped and jagged, I file new edges on them. Here’s how:
• First, I clamp the trowel, edge up, in a vise.
• Then, using a flat file with a piece of wood behind it to keep the file from bowing, I run it the full length of the trowel’s edge in long, even passes. I wear heavy gloves as I do this job and I let the tip of one of my fingers ride along the side of the trowel to align the center of the file.
• I typically remove between 1/16 inch and 1/8 inch of metal to dress a trowel edge. Then I turn over the trowel and repeat the process on the other side.
• Before putting the re-tuned trowel in my tool bucket, I give it a good coat of WD-40 to prevent it from rusting.

— David Whipple, False Pass, Alaska
Tips & Techniques provided by Fine Homebuilding.
©2008 The Taunton Press