Help! Head Snapped Off Tuner Screw...

[Chris of Arabia]

OK, a little problem with 'Braveheart'. Tonight I finally got moving with assembling it all. Unfortunately on the very first screw I tried to fit at the back of the tuner, the screw bound in the pilot hole I drilled and the head snapped off. The remaining part of the screw is beneath the surface of the wood, so I can't get pliers to it. Any suggestions on how I remove it? The others went in fine.

 

[SkuttleFunk]

what kind of shop tools do you have available?

R

 

[Chris of Arabia]

Mostly just small hand tools for working on guitars, but I also have a small drill press, battery powered & mains powered hand drills, a selection of metal drill bits down to 1.5mm, a couple of small g-cramps. I can get other stuff if I know what I'm looking for.

I don't have a vice other than one for working on nuts, no tap & die set, or screw extractor.

Is there enough to work with there?

 

[SkuttleFunk]

a bench top drill press will come in handy for drilling a couple holes around the snapped screw. then take a pair of needle nosed pliers and twist out the broken screw.

once the screw is removed, drill a hole the same diameter as a hardwood dowel. glue the dowel in place a little proud of the surface. once dry, chisel the dowel flush


you're now ready for attempt number two



the same workflow can also work for repairing broken bridge screws. in the case of broken bridge screws, I always wonder what the person was thinking of when they torqued so hard on that poor little screw during installation. what a ton of extra work that could have easily been avoided with the proper diameter pilot hole drilled to the proper depth

all the best,

R

 

[simple]

Since you have a drill press, consider just using a metal bit and drill out the screw in the wood until it's gone. Dowell the hole back up with wood and glue and redrill your pilot hole.

 

[-CB-]

Ya really need to consider doing an archive search here on broken screw.... and getting the right way to fix it.

Drilling it with any sort of drill bit will make the problem worse in most cases.

Drilling it with a hollow drill (tubular) with a hand crank drill ... will leave little mess, and is the right way to do it.

www.frets.com has a few examples, and its been outlined here in the past as well

 

[guitlouie]

http://www.unofficialwarmoth.com/index.php?topic=3404.0

http://www.unofficialwarmoth.com/index.php?topic=1150.0

http://www.unofficialwarmoth.com/index.php?topic=519.0

 

[Chris of Arabia]

OK. I've located some small bore brass tubing from a model aircraft making colleague. Now, do I need to try an file a small number of larger teeth, or a large number of smaller ones? Tried that frets site, but have had no joy in locating the articles that relate to this particular problem so far.

 

[Chris of Arabia]

Think I've found what I need to know for now. Thanks for all the help guys - will update you once I've got things sorted.

 

[ognolman]

I always wonder what the person was thinking of when they torqued so hard on that poor little screw during installation. what a ton of extra work that could have easily been avoided with the proper diameter pilot hole drilled to the proper depth

Somewhere I read to drip some candle wax on the screws before installation to make it easier.  After drilling the proper pilot hole as you mentioned.

It's a little messy, but it does help.

JBD

 

[guitlouie]

I actually went to a craft store and bought some plain, no color, no scent candle making wax in a block and simply rubbed the screws on it before installation.  Less messy and it lubed them up just the same.  But yeah, the correct pilot hole size and depth is the absolute best way to keep this from happening.  Those little tuner screws are fickle, though as evidenced by how often this has come up here.

 

[-CB-]

The idea is to get sharp edges on the wood, so you can grind away at it.  Doesn't have to be perfect teeth, just no "flat spots" on the tubing that will prevent it from gnawing at the wood like we want it to.

GO SLOW with the drill..... DONT USE A POWER DRILL <<<------- REPEAT.... DONT USE A POWER DRILL

Use a hand crank drill and just ease that puppy along letting it gnaw wood - a power drill will bend the tube and fubar things worse.

Crank the drill so the chuck is turning counter clockwise - the same way we want the screw to come out.

~~~~~~~~~~~~~~~

Wax - I just rub my screws on an old candle, and also make sure that the drill for the pilot hole is large enough.  In maple you need a slightly larger hole, in softer woods like mahogany, you can get by with a slightly smaller hole.  Maple is a mofo to screw into if the pilot is too small.

 

[jmasin]

Sounds like you got the guidance you needed.  Good luck with it and just take it slow.  I had this happen on my build just recently and there's no chance but to drill it out.  I went and bought a plug cutter bit so I could make a plug and orient the grain etc.  Common dowels that you can buy are parallel to the grain, so you get the end grain at the top of the plug.  Not sure if this matters to you.

Wax is a must, like others said, and also found this pilot hole guide on the net:  http://sawdustmaking.com/Free%20Charts/Pilot%20Hole.pdf  Up to then I was just guestimating based on eyeballing the bit and the screw together. 

Cheers.

 

[ognolman]

Wax is a must, like others said, and also found this pilot hole guide on the net:  http://sawdustmaking.com/Free%20Charts/Pilot%20Hole.pdf  Up to then I was just guestimating based on eyeballing the bit and the screw together. 

That guide is perfect...  I'm gonna have ta print about a dozen copies!  I've always eyeballed, too, but it's better to just know...

JBD

 

[Chris of Arabia]

Here's another that give the actual dimension in imperial and mm for various gauges of wood screw - wood screw reference data

 

[-CB-]

All those guides are for good screws that are within spec.

Enter:  The Chinese screws, the Indian screws, the Malaysian screws.... all sub spec, all terrible, all needing to be measured for proper piloting.

 

[Chris of Arabia]

You really know how to cheer a fellah up don't you...  :doh:

Actually, I think I'm good on that score. The screw was removed as described yesterday, hole cleaned up and plugged. I should be able to take the dowel down flush to the headstock this evening and carry on where I left off something like a week ago now. It is looking like the tuner will successfully cover the repair leaving no visible trace - if not, a bit of brown felt tip pen on spruce should do the trick nicely...

 

[Chris of Arabia]

Job all done and tuner fitted. No sign of anything, didn't need the felt tip pen