Mold Super-Quick Edge Guards for Sharp Tools

Mold Super-Quick Edge Guards for Sharp Tools

Woodworkers need to keep their tools sharp, and if you aren’t careful, it’s easy to chip them or cut yourself badly on a properly sharpened tool.

Edge guards are a great Maker project, but they can be difficult to construct with a snug enough fit on the tools. Many people have used plasti-dip for this purpose, but plasti-dip tends to be very unfriendly to work with, and can result in a fairly loose fit. Enter low-temperature thermoplastic.


This stuff goes by a few different brand names: ShapeLock, InstaMorph, Fantastic Plastic, and Plasty Craft, to name a few. It comes as a bag of little plastic beads, which you can melt in hot water and form into anything you want. It’s a good choice for this project because it sets up to a very stiff guard, but one which takes on the exact shape of the blade to ensure a tight fit.

Recently, Todd Treece posted a how-to article over on the Adafruit Learning system walking you through the steps to create your own edge guards. The process is pretty straightforward, actually:

  • you simply heat up a load of thermoplastic,
  • form it into a rectangle about twice as wide and long as you’d like the guard to be, and
  • fold it once over the blade lengthwise before folding the resulting shape into thirds around the tool.
  • Once the thermoplastic has partially hardened, the guard can be removed from the blade and trimmed to the appropriate length.
  • After that, allow the guard to cool and dry completely.

That’s it!


And the best part is, the plastic is reusable: if you mess up you can just start over, and trimmed plastic can be re-melted and used for another project. Don’t forget to coat your tools in jojoba or mineral oil before placing them in the guard to prevent rust, and happy woodworking!

1 thought on “Mold Super-Quick Edge Guards for Sharp Tools

  1. Mark L Evans says:

    Great idea, you just never know when a great use for this stuff will pop up. A few months ago my wife handed me a stack of broom handles and heads; they were all in good shape, but nothing matched up. After thinking on it a while I broke out the shape lock and a heat gun and found the best matches and “welded” those suckers. They all have worked great.

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Tony is a web developer from Springfield, MO who enjoys 3D printing, electronics, programming, and anything outdoors. He is currently a developer for Adafruit Industries.

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