Need to cut a circle in fiberglass cloth? Get a hammer.

[ActingLikeAKid]

Was showing my rocket-in-progress to a handyman who'd come to finish installing a door. I pointed out that I had a @!#!# rail button RIGHT IN THE MIDDLE of the body tube between two of the fins, which was going to make tip-to-tip glassing tricky.
He said "Just grab a socket, put it in the middle, tap it with a hammer."

I grabbed a piece of scrap fiberglass cloth and tried it.
I'll be a son of a...
Took a couple of minutes and about ten hits.
Works like a champ and cuts an utterly perfect, smooth circle, apparently by pulverizing the glass under the socket. Makes sense - even in cloth form, it is glass, and glass isn't fond of being smashed with a hammer.

 

[rharshberger]

Excellent technique, thanks for sharing.

 

[manixFan]

Not to be difficult, but usually I just unscrew the button, do what needs to be done, drill through and reinstall. If done while the epoxy is in the green stage, it can be easily cut with an exacto so a drill is not even needed.

But still, learn something new everyday.


Tony

 

[ActingLikeAKid]

That would have wworked great ... if I didn't have the rail button screwed to a weld nut Good call, though, and definitely an argument for "screwing the button in" instead of using weld nuts.

 

[manixFan]

That would have wworked great ... if I didn't have the rail button screwed to a weld nut Good call, though, and definitely an argument for "screwing the button in" instead of using weld nuts.

Ahh, that makes sense. As I like to say, 'it's always something!'

Of course I had to go out in the garage and try it with a variety of things. I tried several brass launch lugs and they also worked pretty well.


Tony