Re: Sawing Plastics (was Re: Primary support -update)

On Sun, 25 Jul 1999 08:28:17 -0600, you wrote:

>Original Poster: "Reinhard Walter Buchner" <rw.buchner-at-verbund-dot-net> 
>Hi Terry, Brian, all,

>5.) Cutting acrylic (Plexiglass) this way is NOT a good
>idea. Usually, it will shatter. For Plexi you need a fine
>toothed blade running at relatively high speed and a
>slow, but smooth forward cutting movement. Drilling is
>very similar (high speed, low pressure).
Acrylic is a pain to power-saw as it softens at a fairly low
temperature. I've always had the most luck using really vicious
coarse, wood-cutting blades rather than fine ones, cutting fast to
avoid hotspots forming.  It's a bit scary (goggles essential!) but
works pretty well. All the sign shops I've been to when scavenging
offcuts use a normal table type circular saw. I asked what blade they
use & they said it's the type designed for cutting aluminium - I don't
know about TPI/tip angles etc. It certainly gives a very clean, smooth
cut with minimal corner chipping.  
At home, I usually use a 6" hand-held circular saw with a nice sharp
TCT blade (about 10mm pitch) for cutting 6mm sheet. It gives a bit of
a rough edge, with some chipping, but is fine for opaque sheet where
the chipping doesn't show up too badly. Obviously as the tooth pitch
is greater than the sheet thickness you have to be careful not to feed
too quickly..

>6.) You donīt need a carbide tipped blade. These blades
>are usually used when you encounter hard materials (nails,
>particle board [the glue is a saw killer], G-10 and so on).
>For equal tooth number, the carbide blade will make a
>rougher cut (esp. if you plan on reducing the cutting
But you do need a very SHARP blade to reduce heating - TCT stays sharp
for ages, If it's not TCT, it might be adviseable to keep a special
blade just for use on plastic.