Instructables

What is the best way to cut Plexiglas or Lexan?

I am building a solar panel, and I need to cut a sheet of Lexan. I have scoured the internet and have come up with a bunch of ways ranging from scoring it to using a jigsaw. None of these seem to yield a good result and a clean edge (even after sanding). I was wondering what your experience was and how you guys cut it or if there are any good resources. Thanks in advance, msweston

ewilhelm5 years ago
Plexiglas and Lexan are different materials: acrylic and polycarbonate, respectively. You can get a very clean edge on acrylic by lasercutting it. Both materials cut well with a band saw or table saw using a high speed with small teeth. A jigsaw might tend to crack acrylic, but will be fine for polycarbonate. From some previous consulting work, I determined that acrylic was the better choice of material for protecting solar panels from direct wear. Acrylic let more light through (around 90%), and better resisted scratching. Acrylic is brittle though, so it has to be completely supported and protected from bending.
mweston (author)  ewilhelm5 years ago
That's what I have heard - that acrylic is better for solar panels - but I am thinking for my application that polycarbonate would be better since its in a high stress situation and if a rock hits it or it gets thrown onto the dock (for use on a boat) I don't want to risk breaking anything. I do have both materials, so I can work with either one... Right now the biggest problem is getting a strait cut. I do not have a band saw, but I do have a table saw, and I've read that you can put the blade on backwards to cut it, otherwise you'll shatter it. This sounds a little weird and I don't think I'll try it; using fine teeth sounds more feasible. I have also seen blades for cutting plastic - not sure how well those work, any input is greatly appreciated!
If you have a table saw I would use that. Make sure the teeth aren't to rough or like you guessed it will shatter. Don't use a hot knife because it is super hard to create a straight line and don't use a torch for this application because the heat transfer will cause it to warp - trust me I have an uncountable number of torches and accessories.
mweston (author)  curecreator5 years ago
Ok, great... I guess I'll head to the HD or Lowe's and pick up a fine-toothed blade!
mweston (author)  mweston5 years ago
Just got a 140 toothed blade for cutting plastic and it works better that all the other methods I've tried!
Don't put the blade on backwards. That's just asking for trouble. You will be very hard pressed to shatter polycarbonate. Just cut a few test strips of both materials to get some experience.
mweston (author)  ewilhelm5 years ago
yeah, I would imagine something bad would happen if you put the blade on backwards. I'll do some tests and see. Thanks
lobo_pal5 years ago
Use a heated blade, you can put it over a fire if you want. That's the most effective way I've heard of. You could also use a butane torch, small hot flame, refillable, but I haven't tried it. You can buy them at Wallmart.
jimwig lobo_pal5 years ago
the teeth to material contact interval will not allow enough heat to transfer to do what you want
lobo_pal jimwig5 years ago
Actually, I found an instructable about turning a soldering iron into a heat blade.
http://www.instructables.com/id/Make_a_Hot_Knife_using_a_soldering_iron/
Dzucky lobo_pal2 years ago
would a laser cutter work?
kevin7314 Dzucky5 months ago

according to this site it will make poisonous gas and destroy the laser:

http://atxhackerspace.org/wiki/Laser_Cutter_Materials

Dzucky kevin73145 months ago

cuz I got my friend to do it with some lexan and everything was fine

mweston (author)  lobo_pal5 years ago
hmmm... I haven't read anything about this. I'll have to try it Thanks
Xamizer5 years ago
I've heard that you should put it backwards through a table saw, because other ways can supposedly melt the plastic. Is this true?
I wouldn't reccomend it, I think you probably get kickback and have a flying piece of plexiglass. At my highschool I just used a tablesaw with a standard rip blade to cut plexiglass. I has no chips. Just push slowly and itl be fine.
mweston (author)  Xamizer5 years ago
I read something similar but I don't think that's the case
You can use a table saw and a special blade designed for cutting Lexan or plexiglass.  Click here to view: http://www.professionalplastics.com/Saw-Blades-Plastic-Cutting
 Use a table saw!    New blade!  5hp motor or larger!     The higher the hp the better the finish on the cut!
pedalmonkey4 years ago
 I spent several years building and installing custom cabinets in corporate and VIP aircraft and had to deal with both on a regular basis.  We just used a table saw with an aluminum cutting blade on it.  One had to use extreme care when cutting.  Go REALLY slow, otherwise you'll experience material drift when the sheet starts to creep away from the fence.  Both materials will tend to sling hot molten shreds of material around the blade and into your face so wear eye protection.  After you're finished, clean your saw out.  It's a really nasty pain in the spleen to deal with but the results are worth it.  If you need the edge to look good just sand it with increasingly fine grits (start at eighty), removing the lines from each preceding grit, and finish with a light, quick swipe of a t-shirt dampened with 1/2 acetone to 1/2 isopropyl alcohol.  A light polishing with rouge will remove the resulting cloudiness.  Have fun.
clark5 years ago
I use a regular knife, just score the plexiglass, use a straightedge when you score it. Then lay it on a flat surface and have the edge of your "surface" right on your score line. Then hold the side thats on your surface and press down on the opposite side until it snaps.
mweston (author)  clark5 years ago
this works well for short distances when I do it, but after about 2-3 feet the crack will change direction and make a bad break.
Actually I have had rather good luck scoring up to 5' lengths of plexi and lexan, the key is that you need to avoid any pressure points. Personally I have used two work benches with an 1/3" gap between them to hold the score while two people bend one end back at the same rate with a 2X4.
clark mweston5 years ago
yup, but for the most part, i find its the easiest method unless your doing larger or more complicated cuts.
curecreator5 years ago
For the most part I would suggest using a band saw or table saw to do the cutting put if you have neither then if you measure and score the sheets with a utility or hobby knife, then you can easily snap it precisely where you want to.
Use what the plastic supply place uses to cut the pieces - a tablesaw with a high tooth count blade designed for plastics (at LEAST100 tiny teeth). On another note, acrylic and lexan do NOT like to be exposed to sunlight. It clouds/yellows them and makes them brittle. I would think tempered glass would be the way to go.
mweston (author)  jamiep5 years ago
yeah, they will yellow, but i am going to be treating this relatively roughly, so the tempered glass would probably break pretty quickly. If I can find an efficient was o cut them then I'll probably make an extra set so I can replace it later on