cutting plexiglass sheets

I think you mean that you want the edges smooth and clear. I assume you are getting good chip-free cuts with the blade you are using.

The professional shops use a torch. It takes a little practice, but the result will be burr free, rounded, almost clear edges.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing. . . . DanG

I assume you mean heat the cut edge up to smooth it out (make it clear), not actually cut the plastic. That could be one stinky mess if ya tried cutting it with a flame.

Since you don't have much of it to cut I would think the blade you have in your saw (circular, jig saw, bandsaw) would suit the job just fine.

Plexiglas can be tricky to cut without chipping the edge. Band saw with a fine blade cut slightly oversize then make a final trim with a flush cut router bit. The best technique to use here is to make a blank from MDF, and then use double sticky masking tape to secure the plastic to the blank. If this edge is not good enough, you can get a polished edge by sanding the edge with some wet and dry then use an alcohol burner and gently pass the edge through the flame. Using a gas torch is possible but it is real easy to bubble the plex.

I usually run it through the jo>

Gerry :-)} London, Canada

Two steps:

2) Then flame treat the edges with a Propane torch, after practicing on some of the scrap to get the feel of how to do it right.

The flame treat will leave a nice smooth glass-clear edge. But an alternative would be to cut them a bit oversized and finish up the edges with a milling machine, which gives a nice frosted edge instead.

Good Luck, DoN.

I did this for my mother right after her stroke (custom tray on her wheelchair), so I wanted a nice smooth finish. I cut the stuff on my table saw with a ATB blade then smoothed the cuts (and beveled them) on my Ryobi jointer treating it like softwood. The physical therapist asked where I got it done, so I guess it came out pretty good (much better than the physical therapist's attempt at it).

I've never heard of anyone getting any sort of heat near the stuff except for bending it. The makers of Plexiglas and Lexan sell polishing kits that will make the edges glassy smooth and clear (use a muslin wheel and the proper polishing compound). If you try heat, be careful as the stuff is flammable and puts out some nasty fumes and can blacken. I think the poster of the heat suggestion was thinking of real glass, not an acrylic...that is how glass edges are polished.

Really? You can get a torch near it without it catching fire?

Hey Jim,

The "pro's" use a table saw, and then run a hydrogen flame down the edge(s) to clean it up. The flame bit is tricky, as in it's an art. Too slow, and it burns; too fast and it doesn't "clean clear". Note they use regular oxy-acetylene torch equipment, but they use oxygen-hydrogen gases instead of oxygen-acetylene, because it burns perfectly clean.

Take care.

Brian Laws>i can get some 1/8 or 1/4 inch plexiglas sheets at the hardare store and

I have actually cut a lot of plex, drilled and tapped, sawed, and even machined on the mill and got a clear see-through finish by applying mineral oil (not mineral spirits) while making the cut. It can be a bit messy but it will leave a clear finish without having to have such a smooth finish. Try it on a scrap piece and see if it works for you. Ron

Score it and snap it over a sharp table edge. Othewise cut with new blade in a table saw or circular saw and dres the edge by scraping with scissors held at a high angle. Lightly polish with fine sandpaper.

On Wed, 19 Nov 2003 23:13:11 -0500, "George" brought forth from the murky depths:

Precisely. Hold it near a nice blue flame and it melts without catching fire or bubbling. Butchagottabequick!

That's the quickest way to deburr plastic I've found. BIC lighters work OK for small parts but are a bit slower and can give you soot damage if you get too close.

-- SAVE THE PARROTS! Eschew the use of poly! ----------

Jim,

At times in the past I have constructed hundreds of 5 sided plex boxes to cover the machine tool models that I have made.

Point 1 There are different grades of plex and different manufactures. Some respond to the above suggestions and methods better than others. Experiment with what you have before you commit to the big money project.

Point 2 There are different sizes of a 'Plasticut' Hand File that can be had for about the same price as a wood or metal file. It comes in flat and half round. It works great for all plastics. With a little practice you can get a clear enough edge to polish it the rest if the ways with auto polish. The File is also great to break the knife sharp edges.

Point 3 Most wood working tools can be used on plex, experiment first. Heat from band saws can be difficult with some grades. Fine teeth for some grades, coarser for others. I like the jointer for straight edges and the router for curved. Then the file and polish.

Remember Experiment.

Jim

jim wrote:

I use a 50 watt laser.......... edges are clear as the face... LOL

Before I had a laser, I used a table saw with a plywood blade (120 teeth or so) and then used a propane torch to dress the edges.

it takes just a little practice, but is actually quite easy to do.

steve

Well, now you have. My wife bought the frame of a very expensive glass topped table for patio use. She got it for next to nothing since the glass had been broken in shipping. I cut out a replacement top from

IT DOES NOT TAKE A LOT OF HEAT! Wave the torch at the edges and watch carefully. You want to see the edge go clear but no other visible sign of melting.

Ted

Somewhere, I have a book from Rohn & Hauss (SP?) (Owners of the Plexiglass trade name), in which this is advised for polishing the edges after cutting (and sanding, if necessary, to smooth up the cut).

Lexan forms bubbles when heated, and thus it needs a different process.

Don't use much -- it is a very quick process with a propane torch.

As I said above -- the makers published a book on processing Plexiglass (*not* Lexan) which advised this very method for polishing the edges. I think that I got mine back around 1971 or so. (Now --if I only knew where it was at the moment. :-)

Enjoy, DoN.

I've had good results with a circular saw and fine tooth blade.

This can be reduced by heating to 100C for a few hours first, to remove water.