Cutting FRP Sheet

[Bob Eustace]

Would 1/4" single flute spiral "O" be the best choice for cutting 6mm FRP? Simple profile with 16 14mm diameter holes.

[jerry_stanek]

Hope you have real good dust collection and may want to use a respirator that stuff is wicked.

[donek]

Fiberglass is extremely hard on bits. When I've cut it with a standard carbide 2 flute bit, the bit is dull after a single cut (hourglass shape 30in X 9in). I'd get a maximum of 10 cuts and then move the bit a little deeper to cut in a fresh section. The cut edge always has to be cleaned up with sand paper. I recently purchased some onsrud burs for fiberglass, but have not tried them. They were very inexpensive on e-bay. Everyone I know who cuts glass or carbon says they are the best choice.

[Brady Watson]

It depends on how many parts you need to make. As Sean points out, they don't last very long at all in FRP. SFSO will work just fine for a one-off or only a few parts before it has to go in the trash.

Don't be scared...go try it for yourself. Nothing like making your own discoveries.

-B

[Sk8MFG]

We cut large amounts of laminated hardwood with heavyweight fiberglass skins.
I've found it's all about feeds and speeds, large chipload seems to keep our bits lasting for about 100-150 cuts (skateboards). Compression bits is a must for us. An up or down cut will leave a very rough edge, or pull fiber from the edge of the laminate in the rare instance.

As for single flute, would seem to me multiple flutes may last longer. Also a burr style bit which has been engineered for composites may be the ticket. I haven't used one personally (wood would gum up the bits quickly).
Here are a couple links,
http://www.toolstoday.com/p-6291-solid-carbide-carbon-graphite-and-carbon-fiber-panel-cutting-router-bits.aspx
http://www.toolstoday.com/p-4928-abrasive-type-plunge-diamond-pattern-plastic-cutting-router-bits.aspx

Of course, PCD may offer the ultimate in terms of performance and durability.

[scottp55]

Totally ignorant, but would either of these(or this type if he can find them) be worth Bob trying? The couple times I ordered from him he was fast. He may not ship to OZ though. Is this what you guys were talking about? Good luck Bob.
http://www.ebay.com/itm/Onsrud-PCL532186-1-4-5-pack-Solid-Carbide-Router-Bits-for-Fiberglass-/380925874910?pt=LH_DefaultDomain_0&hash=item58b0f392de
http://www.ebay.com/itm/Onsrud-PCL532186-1-4-5-pack-Solid-Carbide-Router-Bits-for-Fiberglass-/380925874910?pt=LH_DefaultDomain_0&hash=item58b0f392de

[Bob Eustace]

Thanks guys - this forum really amazes me with the speed in which problems are solved. Special thanks to Brady for PMing more detailed info. Much appreciated by us living in the backwoods!