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Cutting plastic on a table saw

branimal

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I need to cut a plastic door vent down to size for my laundry closet door. The door's stiles and rails are 1 3/4" thick. But the panel is only 1/2" thick. The vent is 1 1/4" thick. If I can remove some plastic off the vent, it will fit snug. Cutting along the red arrow. Can I run the vent thru the table saw without tearing it apart?
 

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Meursault74

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Are you looking to cut it with what you have? Likely the closest blade you'll have on hand is a plywood blade. Not sure it'll work that well on that flimsy plastic. They do make circular saw blades just for plastic though but I doubt you have one or you wouldn't be asking this question.
 

FMB4

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I do not recommend that you use a table saw. Period. Buy a vent to fit your needs, or use a hacksaw.
 

Yankeefarmer

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I have cut a bunch of plexiglas using a dewalt 7-1/4” blade labeled specifically for plywood, laminates, and plastics. Can’t find a good link to one at the moment, but it’s a plain steel, under $20 blade.
 

Shiftless

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Why does reversing the blade work in my application? thx
I made over a hundred cuts through quarter inch think plexiglass using a 10 inch fine tooth plywood blade installed backwards. It kinda melts its way through. No aggressive teeth coming at the plastic snagging any edge and chipping. Very smooth.

Try it on some scrap plastic and see what works better for your application.
 
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like2wheel

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I would cut that in a heartbeat in my table saw. Good excuse to buy a cheap plywood blade. Needn't be carbide. Prob safest backward.

If you're nervous about it, lower the blade height to just score it, then hacksaw the corners & snap off the field. Clean it up with a file or sandpaper.
 

rickpaulos

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Why does reversing the blade work in my application? thx
A forward blade will snag the material and shatter it pretty much instantly. Plastic or aluminum. ruined.

The finer the tooth count the better.

When cutting plastic or aluminum, wear good goggles. the bits of material being removed are larger and have more mass and will bounce in to your eyes. Regular glasses still let the bits bounce off your cheeks and under the edges of the glasses into your eyes. if you have a good face shield wear that too.

When cutting plastic with power tools, the dust gets electrostatically charged and will stick to everything. Messy but vaccums up okay.
 

unslow1

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I've cut a lot of soffit on a table saw but I don't think I'd try that if it isn't easy to get and cheap to replace. If it's cheap and easy to replace then go for it. I would think the right tool for the job is a belt sander.
 

pbon

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Ideally you use a higher tooth blade for plastic but it’s not worth buying one for $40 for 1 cut. Hack saw will do it but use a guide so it cuts straight.
 

walta

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To my eye there is no safe way to push that vent thru a table or band saw and cut along the red line.

The part in contact with the table is maybe 1/8 of an inch wide so it wants to rock from side to side. The part against the fence may not be very flat so it may not slide smoothly along the fence so it could jam making it tip into the blade and get kicked back.

I like the Japanese pull saw idea. You can work slowly and very accurately. The multi tool sounds safe to me

Walta
 

like2wheel

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Miss the Pontiacs

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I’ve cut plenty of low voltage moulding on an electric Mitre saw. Not necessarily mine but what ever is on site. Just nice and slow, more like you are melting through it.
Just be careful if it shatters, you are moving to quick. In that case I always have more moulding, you might only have a limited number of vents. So nice and slow will do the trick.
 

Firstram

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You never know how the plastic will respond, some will and some wont. Jigsaw on lowest setting and a sharp non kerf super sharp blade. Have it secured well.
Bosch T-101B FTW! It's sharp with all rake and no set on the teeth.
 

Viper98912

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If you do this, I recommend using a fine toothed blade, as fine as you can buy. A low-tooth (large gap) blade will instantly shear that plastic.

At the same time, be aware that some plastic, regardless, will shatter. Have your PPE on, as you don't want this stuff to smack you. I've had something shatter on a miter saw, had sharp large pieces flying everywhere, some hit the the wall, some hit me, scared the **** out of me, etc. Be aware when something like this shatters, your body has the natural instinct to jerk up slightly, or also try to grip/push down on the piece, so be very careful not to jerk your hand into the blade and severely injure yourself.

While you can do this safely, just be aware. You have other options, such as an oscillating tool, a dremel, a 4-1/2" angle grinder, etc.
 

SteveCh

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I have cut somewhat smaller plastic pieces with a Dremel, the cutting disc. It can be slow, but if you are only doing one item, works well. You may go through several discs; they are brittle and can snap easily. I had to cut down some plastic elec. outlet covers and could not get a nice, clean cut any other way I tried. Plus, some of the covers cracked when I used plastic/metal-cutting blades in a saber saw.
 

kbs2244

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if you go with the table saw, be sure the slot for the blade it tight
a custom made insert would be a good idea
 

Meursault74

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I have cut somewhat smaller plastic pieces with a Dremel, the cutting disc. It can be slow, but if you are only doing one item, works well. You may go through several discs; they are brittle and can snap easily. I had to cut down some plastic elec. outlet covers and could not get a nice, clean cut any other way I tried. Plus, some of the covers cracked when I used plastic/metal-cutting blades in a saber saw.
Have you tried these?


I've used them to cut plastic with my Dremel.

I don't think I tried the generic 420 type disks on plastic, though.
 

Copymutt

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Any time you’re trying something new w/ a power tool add a full face shield on top of your safety glasses. There are some pretty ugly faces out there that still have two good eyes.
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DanarchyCustoms

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If you are worried about how a saw blade would react with plastic, then use a grinder with a cut-off wheel. Its not the prettiest cut and a bit messy but use the proper PPE. Afterwards clean it up with a sanding block or a file.

I used the same technique on a large model of a NYC building that was made out of 1/4" acrylic for a client. After 10 minutes it was done and did not crack at all. It was $$ and no one wanted to touch it with a saw blade for fear of it shattering.
 

James-W

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Use a plywood blade but put the blade in backwards and then use the fence. Go slow and it should cut the plastic easily. Make certain the plastic you are cutting is in contact with the tabletop on the tablesaw. You do not want the plastic flopping around while you are cutting it.
 
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