Thread: best way to cut a piece of Plexiglass

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Managed to get a good size sheet of plexiglass now we need to cut 2 pieces from it. Last time we attempted to cut pieces from a large sheet we ended up with cracking a big chunk out of it. So before we try again thought to get some suggestions first.

The way I use to cut it was, I would put the blue painters tape on both sides of the plexi where I was going to cut. Then I would use a jig saw with a metal cutting blade and go very slow. You basicly want the blade to melt it as it cuts so don't force it through the cut.

Stinkerbell you musta been reading my mind!!! I asked one of my co-workers about 4 hrs ago how to cut this stuff! I'm going to have to try pdcollins idea because I have a jigsaw. If I remember to get the measurements I might just have the store cut it if thats possible too. I'll let you know how it turns out.

Like pdcollins said. You have to be very careful to go extremely slow when using saw. They have a tendency to create a tremendous amount of rattling with the plexiglass that can lead to breaks if you try to go too fast.

How thick is the plexiglass? You can use a plexiglass cutter which is basically a hooked blade sort of like a razor blade. You start by making a score across the surface then follow up with several passes on the same line effectively creating a small channel. Then after a several passes you can snap the plexiglass back and get a nice smooth clean break IF your passes where all in line with each other. The move each pass deviated from the previous the more jagged your break will be.

Good luck.

I have done this many times.

Line both sides with tape, then score many, many times with a utility knife.

After you have a good groove you can place the part that you want hanging over a work bench and clamp down the other part on the bench. Gently force down the overhang part and it will snap perfectly.

good luck.

If you are going to use a jig saw, I would use a somewhat fine blade. This seems riskier than the above since when this stuff cracks, it seems to crack all the way.

I concur with jhajer. If you want a nice clean line on thin plexi, you have to score the plexi, clamp it FULL LENGTH with support on BOTH sides (I normally use a 2x3 and some C clamps), and then snap it. If you use the jigsaw approach with a fine blade and going slow, you're actually melting the edge of the plexi. When you take it apart, you'll find bits of melted plexi adhering to both sides of the cut. It's fairly easy to clean up, but the edge will be a combination of melted and not melted, which you may find to be objectionable.

For thicker plexi, 1/4 or thicker, you can cut it with a regular jigsaw blade. Tape the area to avoid marks from the saw.

Craig

Yup. I do it the same way as jhajer. Slower, but much more accurate.

Thanks for all the responses. We did the razor knife method the time we cracked sheet, but maybe I didn't score the sheet well enough. We also used sharpie to make our cut line, which was hard to follow, so this time I'll try the painters tape method and I'll make sure to score it better. And we'll see what happens.

Thanks again,

Frog Prince.

its time for the chainsaw....

I have used all of the above with success as well as a reversed blade on a circular saw. I personally prefer the jigsaw. However with all methods i highly recommend using a clamped straight edge. a few years ago we built a plexy coffin and straight edge made it all easier.