Plexiglass?

[Ken Fitzgerald]

I need to cut some 1/8" plexiglass. It's been 40 years since I last cut some.

Any suggestions as what to use to cut it?

[Greg Cuetara]

I have always used my table saw. Make sure to keep the paper or plastic on and the edges won't splinter as much

[Jerry Miner]

tablesaw, high tooth-count blade. Don't let it chatter, or it could shatter. I sometimes run a sacrificial piece of plywood over it to keep it stable.

[James Baker SD]

I use a table saw with a Forrest "No Melt" blade. And leave the protective paper on while cutting as mentioned above.

James

[Joe Shinall]

+1 on the tablesaw. I have a small Craftsman table saw I use on site sometimes to do flooring and other stuff and I just run it through there with a fine tooth blade as to not leave anything on my Unisaw. Cuts good, wear safety glasses for sure. I agree with Jerry on the sacrificial piece of plywood to keep it stable and also keep from splintering as bad. I keep 1/2" ply at all times from a local supplier I get for cheap just for stuff like this and when i need scrap blocks.

[Brian Brightwell]

This has little to do with the original post but the name Plexiglass brings back many memories. Back in the 70's Plexiglass used to be a Rohm & Haas product. They invented it. We would make the syrup in big kettles, three floors high, and poor it hot onto two stainless steel belts ten feet wide and three hundred plus feet long. The long belt was required for big heaters to cure the glass. At the end of the line was a huge saw, like a radial arm saw, which cut the glass on an angle while the glass was fed continuously. It was fun to watch.
We produced a lot of waste and recycled it, plus scrap glass we bought. The process required grinding the 4x8 plus sheets in a 350 hp hammer mill and then feeding the ground up glass into the top of a 20 foot kettle filled with molten lead. The fumes were sucked away and then condensed back into a liquid to be mixed back with distilled MMA {mehtyl methacrylate}. It was a very nasty process. There would be a fire three or four times a week but we had our own fire department. I remember anyone who was assigned to that area would have there blood checked once a month for lead!
Rohm & Haas sold the name Plexiglass and stopped making it. They said the profit margin was too small? R&H sold out to Dow Chemical in 2009 for something like 18 billion.

[Bernie LeBlanc]

Plywood backer is a good idea but also use tape along the cut. I cut fancy scroll work in plexiglass and corian (another resin based product). As the scroll saw blade moves up and down, it tends to heat the corian and binds the blade. I learned that if I cover the work with that clear plastic tape (aka shipping or packing tape), the glue and plastic of the tape coats the blade and keeps it cool. Scroll saws are nothing like a ts blade, but the tape might help cool it down a bit.

[mreza Salav]

Table saw and a good blade, make sure you have good dust collection as well; not pleasant to inhale....

[pat warner]

Stuff that skinny can be routed (http://patwarner.com/images/machining_plastic_a.jpg) straight through, easier than plastic laminate. But I bandsaw it using an 8/12 wavey HSS starrett x 3/8 blade.
That blade, at normal speeds, will slice 1/16 - 5/8" stock without noticing.
Expect some welding on the tablesaw with dull blades, not so on the bandsaw. Moreover, expect the stock to stay down on the bandsaw table.
Watch that chip it can hit you in the face and burn you on the table saw.

[Steve Peterson]

They make special blades for cutting plexiglass and plastic. One tooth has a triple chip grind to clear out the center channel. The next tooth is square to clean out the corners. They have a negative hook. A negative hook miter saw blade in a table saw might be a good choice if you only have a few cuts to make.

Steve

[Andrew Fleck]

If you are just making straight cuts such as cutting to length or width just use a utility knife and a straight edge. I used to work in a glass shop and would often cut plexiglass this way of thicknesses up to a 1/2". 1/8" only requires 2 or 3 scores with a sharp utility knife. Once it is scored just place your hands on both sides of the cut on one end by placing your thumbs on top and pointer fingers on the bottom curled towards you. Lift up and rotate your palms up and that will send the break down the score line. This will really only work if you have at least a couple of inches on either side of the score line. Hopefully this makes sense. It is the same concept as breaking glass except you only score once with glass. No melted plastic this way.

[Charles Wiggins]

Table saw for straight cuts - the BORGs carry blades especially for cutting plastics. Sometimes they are for "plywood/plastics". The have LOTS of LITTLE teeth. I find raising the blade to maximum height helpful (but DANGEROUS!!!). The downward thrust is helpful in keeping the stock on the table, especially with 1/8". If you use a low position like you would for wood the plexi can climb and ride the top of the blade. I've never done it on a saw with a blade guard, so the weight of a guard might be sufficient to keep the stock down. I'd experiment if you have enough stock.
Band saw or scroll saw for curves. Again, I'd use a blade with a lot of small teeth, 14TPI or or more.

Leave the backing on.
Feed rate is very important, you want to go fast enough to prevent heat buildup and melting and slow enough to prevent grabbing and chipping.

[Steve Rozmiarek]

I agree with the special blade. I made a sneeze guard a while back for one of the restaurants, and cutting with a 40 tooth Forrest blade yielded little tiny cracks along the kerf. They got covered up by the frame, but the dedicated blade will work better.

[Bill Wyko]

I cut plexi all the time, I build plexi woofer boxes. I suggest carbide with a 80 tooth or better & a zero clearance fence. For something that thin you may sandwich it between 2 cauls to help prevent chipping.

[Grant Wilkinson]

I used a Freud 6.5" 40tooth thin kerf circular saw blade in my table saw.

[Bill Wyko]

If you need to clean up the edges, start with 220 or finer, any coarser and the scratches will be harder to sand out than cut marks.

[Ken Fitzgerald]

If you are just making straight cuts such as cutting to length or width just use a utility knife and a straight edge. I used to work in a glass shop and would often cut plexiglass this way of thicknesses up to a 1/2". 1/8" only requires 2 or 3 scores with a sharp utility knife. Once it is scored just place your hands on both sides of the cut on one end by placing your thumbs on top and pointer fingers on the bottom curled towards you. Lift up and rotate your palms up and that will send the break down the score line. This will really only work if you have at least a couple of inches on either side of the score line. Hopefully this makes sense. It is the same concept as breaking glass except you only score once with glass. No melted plastic this way.

Used a straight edge, scored with a utility knife and it snapped easily!

Thanks Andrew!