jtranger

First of all, I am not cutting my Corvettes! We are working on friends fiberglass dune buggy body and need to cut a clean hole in the fiberglass.
The hole will not be perfectly round so a hole saw is out. Is there a good tool that will make a nice clean cut in the fiberglass? Thanks

Oaker57

Try a "Roto-Zip" tool, they do a nice job of cutting clean lines through most materials, and have a large assortment of bits. Just test for the right bit on a piece of scrap.

NSC5

The Rotozip style tools are good for this type of work. Just realize you are creating a lot of dust when using any type of high speed cutting bit or cutoff wheel in fiberglass so dress and chose work site well removed from friend's significant other

66jack

Depending how big of a hole but A Coping Saw will work....takes a little longer but more precise...

NSC5

You can also get bits designed for use with a traditional wood working type router that will cut fiberglass and these will allow you to use the various router guides and/or guided bits with a template to cut a very precise opening. These bits are considerably more expensive than those designed for Rotozip tools so I wouldn't take this approach unless you need a very precise cut.

Biggus Blockus

Agree with the the roto zip tool as the tool for the job. I suggest practicing with it on some scrap first if you are unfamiliar with the tool.

Also, I use painters tape over the top of the hole I'm cutting. It seems to help a bunch with getting a smooth edge. I have no idea why, but it does work!

jtranger

Roto Zip sounds like the tool of choice.

KC66

If you use a jig saw use a carbide tip blade. KC

KC John

What about an air powered body saw? They seem to cut metal very precisely, so I would think they would do a pretty good job on glass.

csherman

Dremel

MiguelsC2

Their high rpm and fine blade allow for a very precise cut.

toms silver 60

Rotozips work very well but they can be very hazardous to body parts! Keep it flat/perpendicular to the surface. Do not force the cutting.
I cut out 100+ animal silhouettes out of uhmw urethane and learned to respect it pretty quick.....

steveale

whether a roto-zip, dremel or router...use some type of guide or stop made from wood or hard material. Those tools tend to want to "dig" into the material and you will find yourself "outside the line" before you know it. Also the suggestion of tape over the cut line is a good one, it will reduce splintering of the glass and make for a cleaner edge. Good luck.