On May 4, 9:48*am, notbob wrote:
On 2010-05-04, Ron wrote:

No, just use making tape as I just described.

That may work for plexi 1/4", but is useless when sawing plexi 1".

BTW, the only time I ever used any kind of liquid on plexi, was when I
was drilling large holes through plexi. The liquid used was a tiny bit
of antifreeze mixed with water surronded by a dam and using a
professional tripod drill made for cutting holes in glass. Like this
one.

http://beckerindustries1.com/images/...l_press_lg.jpg

You can use a lot of different liquids, including water and alcohol,
as long as it doesn't melt the plexi. *We used kerosene or stodard's
solvent cuz it was handy and didn't react with the plastic. *NO
ACETONE!!

TIP: the proper way to drill plexi is with a twist drill whose cutting
edges has been "broken" or dulled by grinding, typically just a
"touch" to the grinder at about 45 deg to the cutting edges. *This
is the same for brass and bronze. *We kept whole separate sets of
"broken" drill bits for just this purpose. *It prevents grabbing and
shattering of the material. *With broken twist drills, we routinely
drilled holes as large as 1" dia in 1-1/2" thick plexi. *Natch, this
was with radial drill presses w/ vari-drives that could get down to
10 rpm and after drilling a pilot hole.

nb

The "proper way" according to who? I've drilled hundreds of holes in
plexi using bits made for glass w/o any problems.. Like these

http://www.qfonic.com/images/product...et/image01.jpg

I've drilled holes in plexi using masonry bits which also works well.

Hell, I've drilled plexi with brand new twist bits w/o having a
problem, but of course I have a lot of experience.

I do agree that you can use a dulled twist bit, but I wouldn't call it
the "proper way".

And what about when you have to drill larger holes? I know no easier
way than what I described above.