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PostPosted: Wed Nov 24, 2021 1:09 am 
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Cocobolo
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First name: Josh
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I’ve got an acoustic guitar in where the owner wanted the ancient screw-on strap button at the tail replaced with a regular tapered end pin. Seemed straight forward. Within the first 30 degrees counter-clockwise rotation to remove the existing screw it snapped off just below the surface. Upon inspection it was pretty badly corroded. Not sure there would have been any way to get it out in one piece?

I’ve used brass tubing with teeth filed in to remove tiny tuner mounting screws. Has anyone ever had success using this technique on larger screws? I’m going to need to go down at least 3/4” to get what’s left of this one out. And possibly 3/16” or a bit wider diameter.

Open to other ideas also. If I can keep the hole edges clean I should be able to still ream for an end pin and have it all end up looking neat.


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PostPosted: Wed Nov 24, 2021 4:37 am 
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Cocobolo
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I suppose I could drill a piece of scrap steel as a guide, clamp it in place to stop the bit wandering and try to just drill the screw out with a regular bit. Worried about collateral damage though.


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PostPosted: Wed Nov 24, 2021 6:15 am 
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Cocobolo
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First name: Bob
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Yes you can use the same method but might need to use something a bit tougher than brass, say mild steel tubing. Someone does a set of these extractors, but I cannot remeber who!
Here is a Youtube demo. Drill a hole the same size as the tube in a block of wood and clamp in place as a guide. https://www.youtube.com/watch?v=Q6h5uLmjUN8
Cheers, Bob



These users thanked the author Bob Orr for the post: joshnothing (Wed Nov 24, 2021 6:29 am)
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PostPosted: Wed Nov 24, 2021 8:42 am 
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Quote:
I suppose I could drill a piece of scrap steel as a guide, clamp it in place to stop the bit wandering and try to just drill the screw out with a regular bit. Worried about collateral damage though.


This idea will not work, Josh. Drill bits tend to follow the easier and softest path.

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These users thanked the author Chris Pile for the post: joshnothing (Wed Nov 24, 2021 3:01 pm)
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PostPosted: Wed Nov 24, 2021 3:06 pm 
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Cocobolo
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Thanks for the advice guys. I’ll stick with making a hollow bit. I’ll snap a few screws off in scrap hardwood and do some trial runs to see how clean it cuts.



These users thanked the author joshnothing for the post: Chris Pile (Wed Nov 24, 2021 4:27 pm)
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PostPosted: Thu Nov 25, 2021 10:04 pm 
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I think the hollow bit, riding in a guide, idea has the most promise, says him who's never done it.

Nothing's ever easy with old stuff. Good luck.

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These users thanked the author phavriluk for the post: joshnothing (Sat Nov 27, 2021 6:08 am)
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PostPosted: Fri Nov 26, 2021 12:42 am 
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I’ve done this a number of times and found that making a hollow bit was the easiest way to get it done while leaving the least amount of damage.

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These users thanked the author SteveSmith for the post: joshnothing (Fri Nov 26, 2021 5:14 am)
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PostPosted: Fri Nov 26, 2021 7:33 pm 
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Cocobolo
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Hollow tube works well. Stainless tubing if far more durable than brass tube if you are making it yourself.



These users thanked the author windsurfer for the post: joshnothing (Sat Nov 27, 2021 6:08 am)
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PostPosted: Mon Nov 29, 2021 11:24 pm 
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Cocobolo
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Thanks for the advice everyone. A brief update to close the loop on this one- I was unable to find any steel tube of appropriate diameter locally. Tried some brass tube but wasn’t happy enough with the performance when testing on scrap to put it near a guitar. Ended up ordering one of these from Amazon:

Image

The only size in stock was 5/16th, a bit larger than necessary. Because I wasn’t sure how long this old screw was, I was concerned I’d have to bore all the way through the end block to free it, with potential for an undesirable exit wound on the interior of the guitar.

So first I rigged up some wingnuts, some all-thread and a tube to make a spreader that would hold a scrap block against the inside of the endblock to reduce blowout.

Image

This worked and I ended up with a clean hole inside and out.

The extractor itself functioned well. I found some scrap 1/4” rod which was a tight fit for the ID so I could grip the extractor tightly in a Chuck without worrying about squashing or distorting it.

Image

A guide hole drilled in acrylic was held in place with CA while I did the drilling.

Image

The screw came out without issue. The resulting hole was clean but slightly off-Center.

I had already discussed things with my client and they’d decided now was a good time to get a pickup installed. This meant a larger hole was required, which gave me the leeway to plug, redrill and end up with a neat finish:

Image

The entire off-center extractor hole and its plug fit neatly inside the footprint of the centered Endpin Jack hole. So even with the Jack removed there’s no sign the hole had ever been plugged and redrilled. I’m chalking this one up as a win.



These users thanked the author joshnothing for the post (total 2): Bryan Bear (Tue Nov 30, 2021 8:37 am) • Chris Pile (Tue Nov 30, 2021 12:21 am)
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PostPosted: Tue Nov 30, 2021 12:22 am 
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Outstanding job, Josh. I couldn't have done it any better. Well done.
Great pix, too!

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These users thanked the author Chris Pile for the post: joshnothing (Tue Nov 30, 2021 2:57 am)
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PostPosted: Tue Nov 30, 2021 6:38 am 
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Looks good!

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These users thanked the author SteveSmith for the post: joshnothing (Tue Nov 30, 2021 6:42 am)
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PostPosted: Tue Nov 30, 2021 8:38 am 
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Great job!

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These users thanked the author Bryan Bear for the post: joshnothing (Fri Dec 03, 2021 6:44 am)
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PostPosted: Tue Nov 30, 2021 8:10 pm 
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Cocobolo
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First name: Josh
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Thanks everyone for your help and the kind words. It’s nice to add another technique to the toolbox.


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