Earlier tonight, my dad asked me how I would cut clear acrylic…the 1/4″ thick stuff from Home Depot. I really don’t know. Before I could ask him what it’s for, we got inturrupted.
I’m not real keen on gumming up the tablesaw by doing this. But if it’s safer, I will.
Using a circular saw, what kind of blade is recommended for this? Anything special I should know from a safety standpoint?
tony b.
Replies
YOTONYB,
I wouldnt worry about Gumming up the tablesaw, However, there are blades specifically made for cutting plexiglass. The one I have is made by freud,( I'd have to check but I think they call it an LU89) although you might not find this type of blade at the big box store, there are any number of catalogs you could get it from, also if you find a lumberyard that carries freud blades, theyll get it for you. I have cut a LOT of this stuff on my TS, with no signs of it being any worse for the wear, if you must use a circular saw, youll still need to get a decent blade made for plastic. BTW you can rout roundovers or bullnoses on the stuff with a router table with no problems, to finish the edges. Make sure you open some windows and turn on a fan!, ths smell from this stuff llingers a while. Hope this helps.
E
Tony, I find a bandsaw best for cutting acrylic. no melting, clean cuts, just set the fence (adjust for blade drift if needed). Use any 1/2 blade you have.
Bill
When husband has cut this it was with a blade like a box cutter or utility razor. He scored it deeply along the line and then snapped it on a counter top.
Use a negative hook,thin kerf blade. Keep the paper on. Whichever way you cut it, it's not safer one way or another, it's about accuracy. It won't gum up the tablesaw.
Ther is one safety factor: keep the blade hgt just above 1/4" so the sheet doesn't ride up on the blade.
The people that fabricate out of plexiglas us a Router.
Dick38
I sometimes fabricate with acrylic, one brand name of which is plexiglass, and yes a router is sometimes used. Just as in woodworking a router is sometimes used.
Both materials are cut with a tablesaw far more often, so I'm not really sure what your statement means...
You shouldn't gum up your table saw with cast acrylic. If your dad bought extruded acrylic it will melt.
I cut acrylic all the time on a table saw. It's not a problem. A good combination blade will work fine. The trick is to raise the blade up high so the blade comes down on the acrylic. I usually bring the blade up to it's full height. This holds the acrylic down to the table. Finish the edge with a router.
I know it goes against everything we are taught in high school shop class but it is the safer way to cut acrylic on a table saw.
Len
If you just need to make a few cuts, you can buy a special cutter. It's held like a utility knife, but the design is different and it works better/easier.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I've cut the 1/4" flat stuff on the TS with a 10" combination Forest blade. No gumming if you feed quickly, but it spreads acrylic flakes all over the shop. I cut curved motorcycle windshields with a fine blade on the sabre saw. It will melt the acrylic if you do it dry, but I keep the cut and blade flooded with water from a water pistol or a squeeze bottle.
ooooooooops !
Sorry , just happened to be cutting some plexi , the freud blade model I gave you earlierwas incorrect. The correct number is an LU94. Sorry for the mistake. E
Like someone else said, my first choice would be a bandsaw. But, acrylic won't gum up a table saw blade. Whatever you use, you must wear safety glasses, because acrylic is brittle and can shatter into shards.
Polycarbonate is more expensive, but won't shatter like acrylic so is safer and more durable if your object will be subjected to impact.
If you use fasteners, the holes must be large enough to clear, not so tight you have to work the fasteners through them. You have to thru bolt; you can't thread into it. Also, you cannot countersink (as for flat head screws). Fiber washers under the heads and nuts are not necessary but helpful. Brad point bits or, for larger holes, spade bits work better than standard twist drills. A drill press really helps to make a clean hole.
Thanks to everyone!
Turns out he just needs two small pieces -- 6" x 18" and 14" x 14". I should be able to do this on the table saw if necessary.
I have the cutting tool which I use for the thin, non-glare acrylic for my picture frames. I just wasn't sure how easy or difficult it would be to "score-and-snap" the heavier stuff. I might try this first at home before I lug everything to the shop and make a production out of it!
Wayne, thanks for the advice on the fasteners. Turns out he wants to use these like a storm window in a bathroom to replace an inside screen during the winter. Not sure how wise that is...but I trust his 50 years of experience versus any reservations I might have!
Thanks again for the quick replies!
tony b.
Edited 8/13/2004 2:05 am ET by YOTONYB
Tony, I re-read Wayne's post and didn't see anything about using a plastic-specific bit to drill the holes with. As he said standard twist drill don't work well (an understatement, for sure). The bit I have is shaped like a rounded arrow. Works very well.
The trick to using the scoring tool on the thick stuff is to score, score, score, and score, LOL! Of course, you're probably stronger than I am, so might be able to score half as much. Once there's a tiny groove for the tool to ride in, it's pretty easy.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
you can use regular twist drills to drill sheet acrylic but you have to "blunt" each cutting edge a couple of thousandths. just enough to remove the shearing action. once you're done you can easily resharpen. the hazards of a sharp drill is that it "digs in" cracking the plastic, while the blunted drill sort of wears thru.
Gotcha.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I am not sure of the provenance of this, it was passed to me in a master-apprentice relationship, although I am sure that there are formal setups.
Metal tools have all of the same issues about sharpening and bed angles as do planes. You would need to experiment a bit, but if you increase the cutting angle so that it is like between 80-90* and dont change the relief angle (if the relief angle is too shallow there will be friction and heat which is not good for acrylics) you will have the drilling equivalent of a scraper plane. A small slipstone will be sufficient because the new bevel needs only be small.
As said in an earlier post, most of the risk is as the bit first penetrates the back of the acrylic, and the cutting edge pulls the bit through faster than it cuts. Some of this can be avoided by drilling into a board.
I had a warrant officer who had separate drills for ferrous, non ferrous,and plastics - none of his staff would have been game to touch a piece of wood with these. He told me that he had been taught grinds suitable for fingernails, and we had a bit of an adventure once with bone (a doctor thought he might need to put burr holes into a patient after a head injury and the warant officer was trying to get it right) The point being, the drills are cheaper than damaged materials and easy to fit to requirements.
For just a couple of pieces, reach for your scoring knife, handsaw and file. You'll be done in the time it would have taken to set up a powersaw, and safer.
Edited 8/18/2004 7:29 am ET by kiwimac
I made a base for my router out of 1/4 inch clear acrylic or polycarbonate, I don't remember which. I counter sunk the holes for the mounting screws and later drilled and tapped for 1/4 by 20 threads so that I could add a fence underneath. I just used standard drills, taps and counter sinks.
Acrylic, being brittle, can sometimes break from stress points such as threads and under wedging action such as flat head screws. I'm glad your bases worked out fine.
The last time I cut acrylic I used the ts. I did it in several passes raising the blade a little each time until it cut through. Just used a normal combination blade.
Good luck.
Yotonyb,
I recently had a plastics place make me some 12" wide shelves with a turned up front to hold the sculptures I was putting on them out of 3/8" clear plexi. The turned up front was about 1" and I only wanted about 1/4". Rather then bring it back I asked him what I could cut it with and he suggested an 80 tooth carbide TS blade. Thats what I used. I sanded the rough edge with increasing grits of sandpaper starting with 150 and ending with 1500. Took all the saw marks out and polished the edge so you can't tell the difference.
ASK
have em cut it to size when ya buy it, no brainer that way.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
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