Cutting plexiglass - tips or techniques?

[BryanH]

Had a frustrating time with a sheet of plexi-glass. Trying to cut replacements for my VMC110 bottle door.  Sheet is 1/8" thick.  I've been using my jigsaw with a fine tooth blade with no luck.  If I go slow it heats the plastic and melts the edges. If I go fast it chips and cracks.

How do you guys & gals do it?

[Creighton]

PITA isn't it!! Hardware store had a saw called a "Shark Saw" if you use a board to help stabilize the blade it works ok. Might be for cutting PVC, can't remember.
Creighton

[MoonDawg]

With a steel straightedge and a carpet knife, you should be able to "score" a deep groove into both sides of the plastic.  Laying it on the edge of the table it should break at the weak spot, right  along the line.

The straight edge and razor knife have always worked best for me.

[glassbottlesrule]

Glen is right.  The score method works the best unless it is a polycarbonate such as Lexan.  If it is just plexi score several times against a straightedge.  Take to the edge of the table and snap off.  If you are going to cut a bunch I suggest you go to your local glass shop and buy yourself a plexi-cutter.  The brand we use at work are Fletcher's and they seem to be about the best.  It should be under 10 bucks.

[dprat1]

I saw a method on a hot rod show that I have tried just out of curiosity. The plexi is scored as Glen described but just prior to snapping it, pour a small amount of rubbing alcohol along the cut and then light it. as soon as it flames out,,break it along the score. Know it sounds silly,,but it seemed to work when I tried it. I think the brief heat is enough to weaken at the score line but won't melt or burn the plexi. I suggest a practice piece first. Good Luck.
doug

[BryanH]

I tried the scoring method originally... It worked even worse for me but I think it was the case of not scoring it deep enough and only on one side.  This might be a case of my patience-defficiency getting in the way of doing a good job.  I'll try again... if it doesn't work I'll go with Doug's up-in-flames method - with extra fuel to reduce it to a bubbling mass of goo

Guess the type of material might affect what works.  I have cut thicker plexiglass type material with a jigsaw.  The lighter more plastic types of material, like panels for overhead ceiling lights, worked very well with the knife and straight edge.  I scored them from one side only, several strokes until the pressure of the scoring  caused them to snap off.  Always on a flat surface for support.

[aspbear]

I use a band saw and when I get the area of the cut measured, I run masking tape down both sides. Then I measure for the cut and use the band saw to cut through the masking tape, no splinters and no melting. There may be a rough edge that will just crumble away.  I usually cut the 1/8 inch and thicker this way with no problems.  The thiner stuff I use the score and break method..

[kstt]

No, no! Use a table saw, fellas. Carbide blade (+/- $10), keep the blade up a little high (so the plexi doesnt' "walk" up over the blade), hold snuggly and take it slow. I manage a carpenter shop and we do it all the time. I just cut 3 pieces for the door on my Cavalier 72, in fact.