Utility Knives And Plastic Don’t Mix
A utility knife is one of the few tools that is always in my tool belt and is on my top-ten list of often-used tools. They have many applications, but cutting plastic not one of them. As a matter of fact, utility knives should just stay away from plastic all together.
Utility knives dig into plastic and don’t ride consistently. They will cut smoothly, then just as quickly, dig in and get stuck. Or, they might just completely release and hop around uncontrollably. And, plastic has no grain direction, so there is nothing to direct the knife and an errant cut could go anywhere.
The worst cut I have ever had came from using a utility knife to cut plastic when I was in college. I had a project laminated and was trimming it to size with a utility knife while using a metal ruler as a straight edge. The plastic was thick and I was pushing down hard. Before I knew it, the knife slipped and I cut a corner of my fingertip almost completely off. The only thing that stopped it was my fingernail, which did not cut through.
Also, while I was in college a classmate was doing the reverse. He was using a plastic triangle as a striaght edge and the knife hooked into the plastic and jumped over his outlayed thumb. He was a big guy and it made a big mess. He went to the ER and they sewed it back together again.
If I ever cut plastic with a utility knife I am extremely careful, and I make sure to keep my fingers bent so the knife doesn’t just ride over them if I do slip. Hopefully, the handle will hit a knuckle before any real damage occurs.
Very recently, I was working with a friend who was cutting plastic wire ties off of some new lighting fixtures we were installing. I wanted to say something about plastic and utility knives, but I didn’t. I thought he was smart enough already and didn’t need my two cents. After a couple of minutes, I heard the yelp that I was expecting. I knew what he did – he cut himself with the knife. But what really makes the story worth telling, is that while we were looking for a bandage he said, “That was the third time I cut myself this morning.”
Remember: Utility knives and plastic don’t mix.