Filament wound vs. convolute G10 fiberglass

[Warren B. MusselmanModerator]

Well don’t keep us in suspense – What are the right tools for drilling clean holes in filament wound fiberglass?

Warren

[Doug GerrardParticipant]

If you’ve worked with G10 you are probably already aware that toothed instruments such as saw blades, and drill bits, absorb almost all the heat generated since the G10 is such a great thermal insluator. So you burn up a lot of blades and bits. However, you can sand or grind G10 just fine.

I use Diamond bits for cutting slots and drilling holes in the tubing.
Here is a link for diamond cutoff wheels for your Dremel tool:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=31501

Here are two links for some diamond drill bits
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=36252
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=32351

There are other places to get these but they frequently go on sale at Harbor Freight. Often I may start a hole if a smaller size twist drill bit but then use a the diamond bits for the correct size you want. Since they sand the tubing it leave smooth holes. For very large holes use a sanding drum.

Doug

[Bruce R. Schaefer]

But, Doug, filament wound isn’t G-10. I thought only convolute is G-10. Or did I just learn something new?

G-10 and G-11 (Glass Cloth / Epoxy Resin)
These glass-epoxy laminates are specified for their extremely high strength and high dimensional stability over temperature. G-10 and G-11 are used for terminal boards, high humidity applications, electrical and electronic test equipment and electric rotor insulation. G-10 and G-11 are difficult to cut or machine and may require special equipment. G-10 is slightly stronger while G-11 is a better insulator and can take higher temperatures. FR-4 is a fire-retardant G-10 glass-epoxy laminate that is used primarily in the printed circuit board industry.

The thing I like about cutting it is that it smells like a circuit board. I guess I can assume that both FW and C both are/ or can be G-10?

[Doug GerrardParticipant]

I guess I can assume that both FW and C both are/ or can be G-10?

I guess I have made that same assumption as well. I know it has fiberglass and epoxy and the best way I found to cut that is with the diamond bits. BTW, they work very well on carbon products too.

Doug

[Warren B. MusselmanModerator]

What makes a material G10, G11 or G12 or their corresponding fire ratings of FR4 FR5, etc. is the epoxy that forms the substrate and the way they are manufactured. It has to do with fire rating so the epoxy has EVERYTHING to do with it. Also, typically G10 circuit board material at least is compressed during layup with several thousand PSI of pressure.

Warren

[Conway StevensParticipant]

Actually G10 comes in many forms be it Sheet/FW/CW products. G10 is a rating of the glass its strength and temperature abillities. So all the above can be G10 or other ratings dependant on the materials used. Normally G10 is tougher and has higher heat abillities. Its also harder to cut drill and ect.

[Bruce R. Schaefer]

Thanks, guys! Doug both you and Chris LaPanze mentioned the right diamond cutting wheels for fiberglass. I finally went out today, in the snow, and bought the right ones. I used #409 before and while that one works, you’ll chew ’em up. Diamonds aren’t just for our girls. 😉

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