Zero Clearance Insert From Lexan?

[Bill Space]

Hi,

I can get 1/2" thick scraps of Lexan from work and wondered if this material would work for a ZCI. I might also be able to get Micarta, but that is not certain at this point.

The clear Lexan would offer the advantage of seeing into my Grizzly G1023RLWX, to verify that the blade dust chute is not clogging up.

I think I can drill and tap the Lexan to hold the set screws for setting the insert's elevation. If not I could epoxy in some nuts underneath to serve the same function.

What do you guys think?

Thanks for any advice/opinions!

[Andrew Joiner]

I think it would work fine. May sag I tiny bit but nothings perfect.

[Wade Lippman]

I've used 1/2" corian; lexan should be even better. I taped mine.
I wouldn't expect 1/2 to sag over 4"... Router plates can sag, but they are much bigger with a heavy router hanging off them.

Micarta would be perfect if you can get it.

[Pat Barry]

I'd say no. The friction of the blade rubbing on the lexan will melt it. It might last a while though but not nearly as long as mdf

[Richard Coers]

I'd say no. The friction of the blade rubbing on the lexan will melt it. It might last a while though but not nearly as long as mdf

+1 on the heat comment. You are going to transfer some material to the blade, and you may even have a chance of welding the blade to the lexan. Besides all that, it will STINK!

[Steve Rozmiarek]

What would rub? The plate of the blade is thinner than the kerf, the teeth stick out a bit. The plate won't touch it once the initial plunge cut is made. As the blade flexes and warps in cuts, the teeth will shave off a tiny amount where they run too, and the teeth won't touch longer than the first cut through stock.

[John McClanahan]

Well, there's one way to find out. :D

[Michael Mayo]

I just made a ZCI out of some left over HDPE Starboard and it has worked fine no melting what so ever I don't think you would have much problem using the lexan for the already mentioned reasons. One way to find out make one up and see.

[Bob Wingard]

It will work just fine ... and ... in that thickness & dimensions, there will be NO SAG !!! C'mon guys ... REALLY ??? ... you're predicting sag in a piece of material maybe 4" X 9". And now ... the blade will "glue itself" to the insert ... have you guys ever actually cut LEXAN before ??? I have made dozens of inserts out of LEXAN, and have never experienced any of these characteristics.

If you are going to drill/tap LEXAN for adjustment screws, I would suggest either you do it from the bottom, OR use a countersink on the top to remove a slight ridge that will probably form around the hole ... a slight "cratering" effect that is common to plastics in general, and especially in polycarbontaes. Other than that, you need not worry about any special cautions or procedures.

[Steve Rozmiarek]

It will work just fine ... and ... in that thickness & dimensions, there will be NO SAG !!! C'mon guys ... REALLY ??? ... you're predicting sag in a piece of material maybe 4" X 9". And now ... the blade will "glue itself" to the insert ... have you guys ever actually cut LEXAN before ??? I have made dozens of inserts out of LEXAN, and have never experienced any of these characteristics.

If you are going to drill/tap LEXAN for adjustment screws, I would suggest either you do it from the bottom, OR use a countersink on the top to remove a slight ridge that will probably form around the hole ... a slight "cratering" effect that is common to plastics in general, and especially in polycarbontaes. Other than that, you need not worry about any special cautions or procedures.

Dangit, I was going to blame my declining eyesight on these sagging polycarbonate lenses in my glasses!! ;)

[Richard Coers]

It will work just fine ... and ... in that thickness & dimensions, there will be NO SAG !!! C'mon guys ... REALLY ??? ... you're predicting sag in a piece of material maybe 4" X 9". And now ... the blade will "glue itself" to the insert ... have you guys ever actually cut LEXAN before ??? I have made dozens of inserts out of LEXAN, and have never experienced any of these characteristics.

If you are going to drill/tap LEXAN for adjustment screws, I would suggest either you do it from the bottom, OR use a countersink on the top to remove a slight ridge that will probably form around the hole ... a slight "cratering" effect that is common to plastics in general, and especially in polycarbontaes. Other than that, you need not worry about any special cautions or procedures.

I work Lexan all the time at my day job, and I don't have a single zero clearance insert, of any material, that is pristine. All of them have had side cutting from slivers getting stuck. It's not improbable that you could get a side rub and transfer material from the insert to the blade. The Forrest blade has very little side set in the teeth to get somewhat of a "burnish" to the cut. Blades ground like that may be the worst for rubbing on the insert.

[Larry Browning]

I say just make one and see what happens. It won't cost you anything and what's the worst that can happen? A little melted plastic? Or maybe a slightly gunked up blade. I'd bet you have an old blade laying around somewhere. Let us know how it turns out.

[Erik Loza]

A few of our sliding table saws have lexan cover plates over the ports in the cast iron table top, where you do the belt change for the various speeds. Holds up just fine, except becomes hazy with use from the wood passing over it. No sagging and way bigger than any ZCI plate.

Erik Loza
Minimax USA

[Pat Barry]

I'll defer to those with positive experiences. I'm just identifying what could go wrong. I'm personal friends with Murphy and believe his laws are valid.

[Alan Schwabacher]

Polycarbonate (Lexan) is not acrylic (Plexiglass). Problems with melting, particularly if it's smelly, are much more likely with acrylic. As far as strength is concerned, it's like comparing hickory to balsa.

[johnny means]

I wouldn't count on the transparency being a benefit for too long. Can't see why it wouldn't serve as a ZCI, but IME it cracks to easily.

[Bill Space]

Thanks to all for their input!

I think I will make a ZCI from the Lexan and see what happens and report back.

Also, it looks like I may be able to get some 1/2 inch thick micarta scraps as well, so I will try that also if that comes about.

Lexan is SO MUCH tougher than acrylic. It is acrylic that cracks easily in my experience. I don't expect that cracking would be an issue with Lexan (polycarbonate) . Night and day difference between the two.

I will report back, but it will be a while as I need to re-pipe my dust collector system to accommodate the new saw and jointer, and change the feed to one of my bandsaws... and use my shoehorn to get things back in place so I can work in a reasonable manner.

Anyway, happily, if the lexan does not work out I should have material to make several micarta ZCIs, so life is good here in my workshop!

Thanks again, Bill

[Jeff Bartley]

Bill--let us know how it works out. I'm sure it'll work great. To level the insert I'd drill and tap it for headless set screws then use weak locktite so the screws wouldn't move around. I like to use lexan for router jigs. Jeff

[Bob Wingard]

I wouldn't count on the transparency being a benefit for too long. Can't see why it wouldn't serve as a ZCI, but IME it cracks to easily.

In all my years of using LEXAN for LOTS of things ... I've NEVER seen a piece crack ... it is literally bulletproof. Surely, you have confused it with acrylic or some other plastic.

[Mike Cutler]

All I can tell you is that I have made many of them through the years and have had no problems.
I use them mostly for ZCI's when I use dado blades, and probably have a 1/2 dozen or so in various cutout widths and angles.
One thing to be aware of is that there are many formulations of the product known as Lexan. ;)

Bottom line is that they work,and work well.