# How to identify plexiglass?



## randyrls

I am thinking of trying a plexiglass finish on some pens.  

I have some sheet plastic in my shop, but I'm not sure if it is lexan or plexiglass.  I've considered just putting it in acetone to see if it dissolves.

So is there a way to identify plexiglass?


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## snyiper

Try this:http://www.texloc.com/closet/cl_plasticsid.html


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## Sylvanite

Some pratical ways to distinguish between plexiglass (acrylic) and lexan (polycarbonate):

1)  Scuff the surface lightly.   If it scratches easily, it's acrylic.  If it won't scratch short of a sharp awl or sandpaper, it's polycarbonate.  

2)  Drop a sheet on a cement floor.  If if shatters into hundreds of sharp fragments that fly all over the shop, it's acrylic.  If it dents the floor, it's polycarbonate.

3)  Stand a sheet up and throw a rock at it.  If the rock goes through, it's acrylic.  If the rock bounces back and hits you, it's polycarbonate.

4) Break off a small piece and drop it in acetone.  If it dissolves, it's acrylic.  If you can't break off a small piece, it's polycarbonate.

 Eric


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## randyrls

Sylvanite said:


> Some pratical ways to distinguish between plexiglass (acrylic) and lexan (polycarbonate):
> 
> 4) Break off a small piece and drop it in acetone.  If it dissolves, it's acrylic.  If you can't break off a small piece, it's polycarbonate.



Eric;  Thanks for the info.  I was able to break a piece off so I believe I have plexiglass acrylic.  Now I need some lexan to make a shield for a dust hood I am making.

snyoper;  Thanks for the link....  It explans a lot about how to id different plastics.


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## BigguyZ

You know, I have a chuck of polycarbonate...  wonder what I could use it for...


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## rjwolfe3

> I have a chuck of polycarbonate...  wonder what I could use it for...



See #3 above - should provide plenty of fun!


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## PaulSF

That must be some garbagey acrylic if it breaks that easily.  We use lots of acrylic here in my picture framing store, precisely because it is so hard to break.  I'd say that if you throw a rock at a sheet of acrylic and it shatters the acrylic, then either (1) you should be pitching for the Rockies, or (2) it isn't acrylic.


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## KD5NRH

BigguyZ said:


> You know, I have a *chuck* of polycarbonate...  wonder what I could use it for...



Does it hold as well as the metal ones? :wink:


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## Len Shreck

Plexiglas is very hard to drill threw I have found it is better to heat something to red hot and push it threw it. Just wanted to add my 1/2 cent. Len


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## KD5NRH

Len Shreck said:


> Plexiglas is very hard to drill threw I have found it is better to heat something to red hot and push it threw it. Just wanted to add my 1/2 cent.



Tape both sides, then drill slowly.  Blue masking tape in a pinch, but the Scotch removable clear works great for small holes.  You'll probably also want to have it tightly clamped to a sacrificial backer to prevent blowout.


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## KD5NRH

randyrls said:


> So is there a way to identify plexiglass?



Well, you could see if there's a new edition of this for modern materials:






:biggrin:


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## DurocShark

:biggrin:

The shelf tag will usually say whether it's acrylic or poly. As long as you're starting a new batch, if you accidentally put poly and acetone in that jar you just have poly and acetone. Pour it off and start again with the right material.


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