Can I drill through carbon fiber?

[Jens]

Can I drill through carbon fiber? I want to modify some gear.

[Blake]

sure you can

[TrogdortheBurninator]

depends on the gear and location of the hole. Carbon fibers are strong because they are continuous fibers. The introduction of a hole creates a stress concentration as well as a discontinuity in the fibers. If you need to fasten two things together, you should really consider an adhesive. Otherwise, you might want to reinforce the area around the drilled hole with some sort of patch.

[AR_Guy]

Use a very sharp drill bit and tape the area you're going to drill to reduce the fibers tearing out of the plastic / resin matrix. Also, back up the piece you're drilling through so you don't blow out the back with drill pressure and tear out a bunch of fibers from the matrix.

 

Be sure to leave plenty of edge margin - at least 2 and preferrably 3 times the fastener diameter from the edge of the pieces you're joining, otherwise the joint is susceptible to failure by tearing out the line of fasteners. Select bolts / bits such that you have a snug fit of the bolt in the holes, and pick your bolts so that the threads don't bear on the pieces being joined. Use smooth shank bolts and washers as needed to achieve this. Don't overtighten the bolts or you can crack the plastic resin that supports the fibers, weakening it greatly.

 

Regarding Trogd's comments: For joining thin pieces, adhesive is superior as noted. For joining thicker pieces (1/2" and up, roughly) of composites, bolted joints (when designed properly) can be stronger (strong adhesive joints for thick pieces get VERY complex). As noted, a doubler or adhesively bonding on reinforcing material around the joint before fastening it together is a good idea. Be sure that the fibers in the doubler run in multiple directions (N-S, E-W and NW-SE, NE-SW - to use points of the compass as direction indicators). Having fibers in these directions tends to make a piece of composite material stronger when it has a bolted joint.

[catbirdseat]

Can I drill through carbon fiber? I want to modify some gear.

I take it the gear is the shaft of an ice tool? I would avoid it if at all possible. We had a carbon fiber spinnaker pole break on us once. It broke at a hole someone had drilled to fasten an eye for the foreguy or topping lift. The best approach is to use some sort of band that runs around the shaft, fastened with adhesive.

[John Frieh]

I have a pair of grivel monsters for sale.

[Lambone]

Probly not a good idea Jens.

[dbb]

I have a pair of grivel monsters for sale.

 

hahaha, I think you read his mind John.

 

Jens- grivel hooks on the bottom of cobras?

[Dechristo]

As far as appropriateness of your modification(s) as concerns structural strength/integrity, I'd contact the manufacturer directly.

 

But, to minimize break-out when drilling, follow AR_Guy's recomendations AND pilot the hole first with a smaller diameter bit (perhaps two pilots in increasing diameters), then chase with the finish size bit.

 

Depending on your application, you may need to slightly chamfer the hole openings.

[Mr_Phil]

Sure. Drill away.

[Dechristo]

Is that a personal invitation?

[cj001f]

Is that a personal invitation?

 

you can tap his ANWR

 

sure you can drill Carbon Fiber. Will the device be durable afterwards is the question

[olyclimber]

I don't know what you're up to Jens, but if you have Cobras check this out:

http://www.cascadeclimbers.com/threadz/s...true#Post542763

[Jens]

Thanks for all the insights.