Cutting Lexan

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That's pretty much it. What's the best way to get a clean cut.

I used a jig saw with a "smooth wood blade." After cutting, the Lexan was left with a serrated edge that didn't look very good. So, I sanded the edges with course sandpaper using a belt sander than by hand using fine sandpaper. This made the edges smooth like glass.

-- Roger
As Fred just said: Cutting .010" to 1/4" thick Polycarbonates: to obtain the cleanest cuts you'll need a scribing knife (Sharp) with a metal straightedge. Best to make several passes, letting the tool do the work, Pressing hard only causes slips and errors. Once your about 2/3rd of the way through the piece will snap along the score line. clean up the edge with a file and sanding block. It's possible to bring the edges back to optical clearity with progressive grits to 600 papers.

If your cutting really big pieces then it's possible to use an 120tooth hollow ground carbide tipped blade to obtain good cuts or a cad/cam controlled router with a carbide router bit.

470g1-sm_Forgotten Apache fins, template & spare_08-30-07.JPG
Thanks, I'll try to find a good knife tonight. Not a big project, building a 2 foot beer bottle. If anyone has pics of beer bottle odd roc, it would be helpfull.
There are jigsaw blades that will produce very clean cuts; most won't, but there are a few specific ones that will. I'll try to remember to look up the specific blade when I get home -- I was surprised at just how well it worked!

I do remember it's a Vermont American blade, and sold at Menard's, if you have one in your area....

I've built a lot of display cases and stuff where you need dead straight, square, smooth cuts in order to get good solvent welds. I've always cut to about 1/16" oversize with a fine tooth carbide blade on the table saw and then cleaned and straightened with a router mounted in the table saw's extension table - so I can use the rip fence for very straight and very parallel pieces. This leaves me running the material between the fence and the router bit which has questionable safety implications. The safer plan would be to clamp a straight edge to the lexan and guide the router against the straight edge - far safer but also far slower.

The jigsaw blade I use is a Vermont American 10 TPI wood blade; part #30016. It leaves an amazingly smooth edge -- I'm sitting next to a piece that's being used to protect my screen from the dog, and the cut edges are visible.

The standard way to cut it is what Mike referenced -- use a table saw blade, then clean up the edges with a router. When solvent-welding, that's how it's usually done, as you have to have a really, really good fit, which means a nice, clean edge.

I was cutting thicker - 3/16" inch, I think - pieces of Lexan. I tack glued four sheets together since I was cutting four fins. I used a fine-tooth jigsaw blade like Kevin described, but I guess it wasn't exactly the right blade because I did have to clean up the edges later.

But, having the pieces glued together made it easier cut out the fins and to sure all four were the same shape and size. Since the sheets are covered with protective paper, it was easy to peel them apart later.

-- Roger
Guess we should always ask what thickness is being worked with.
As Roger posted Stack cutting is an excellent way to get all you pieces the same size. We use this method at the Sign Shop constantly. If you have access to double faced masking tape it makes the unstacking job a bit easier.

Generally for Polycarbonates over 3/16" we also prefer 18t bandsaw blade when cutting shapes if not done with the Cad/Cam router, cuts down on the waste. Thinner stuff and Home projects like fins are generally done with a scribe knife and straightedge as discribed earlier.

Hope this helps.
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Thanks, that reminds me that my neighbor has a good band saw. Guess I'll be knocking on his door soon.