Brocken screw…inside bridge hole

[Camarillo]

I’m in the process of “restoring” (no pro here) a 1979 Yamaha Pulser Bass. Finished the cleaning and fixing minor issues I was re-assembling the bridge an one of the 5 screws has broken inside the hole (electric screwdriver just for the initial turns, then hand screwdriver to avoid to tighten too much, but…not enough grace for a 40 year old screw maybe….).
What am I gonna do now?

 

[TheReceder]

When life gives you lemons, make lemonaide. (Buy a new bass)

I can only hope that there are people with more intellegent responses... all I know is if that was my bass, it might have to live with evidence of severe butchery under the bridge, or the wonder of a screwhead glued to the bass with only 4 remaining screws attaching the bridge.

Again... I sincerely hope that there's someone that comes up with a better fix than messing with an easy out.

 

[Smilodon]

You could make a core drill and drill it out. Get a small piece of pipe that fits around the threads of the screw. File saw teeth in the end of the pipe. Then drill down to the broken screw with a drill the same diameter as the pipe. When you reach the top of the screw you switch to the pipe and cut down to the bottom of the screw. (use one of the other screws as a depth gauge). Break off the "plug" you just cut and glue in a dowel. Now put in a new screw.

Edit: You could try to drill out the screw, but the dill will most likely wander off into the wood.

 

[TheReceder]

You could make a core drill and drill it out. Get a small piece of pipe that fits around the threads of the screw. File saw teeth in the end of the pipe. Then drill down to the broken screw with a drill the same diameter as the pipe. When you reach the top of the screw you switch to the pipe and cut down to the bottom of the screw. (use one of the other screws as a depth gauge). Break off the "plug" you just cut and glue in a dowel. Now put in a new screw.

I knew there were way more intellegent people out there

 

[DrBnz]

They make screw extractors (or EZ outs). That's almost too small but I'd have to try it. This one will be challenging since its recessed so far. So you got a good project bass..... Its not gonna be boring. OR
How many screws are in that bridge? If it has 3 or more I'd consider going without it.

 

[Camarillo]

You could make a core drill and drill it out. Get a small piece of pipe that fits around the threads of the screw. File saw teeth in the end of the pipe. Then drill down to the broken screw with a drill the same diameter as the pipe. When you reach the top of the screw you switch to the pipe and cut down to the bottom of the screw. (use one of the other screws as a depth gauge). Break off the "plug" you just cut and glue in a dowel. Now put in a new screw.

Edit: You could try to drill out the screw, but the dill will most likely wander off into the wood.

That seems difficult

 

[Camarillo]

They make screw extractors (or EZ outs). That's almost too small but I'd have to try it. This one will be challenging since its recessed so far. So you got a good project bass..... Its not gonna be boring. OR
How many screws are in that bridge? If it has 3 or more I'd consider going without it.

It’s a classic 5 screws vintage Fender style bridge.
I have a screw extractors kit but the smallest is way bigger than the hole

 

[jTrolt]

This is straight from A-zon's product image. $15 - I think you can get the concept a bit better from this image. It's simply called a "Woodriver Single Screw Extractor". As you can see at the lower right- this will be the end result. To get started, grab a scrap of wood and bore to about the outer diameter of the above extractor. This way, you have a collar to control the hollow tube saw, which otherwise would wander all over on you since there's no center point to guide it. Then, simply stab in a dowel of the right size, cut flush. Set your bridge with the good screws, use the hole in the bridge to mark/punch dead center, drill a small pilot and voila- like it never happened.

Good luck. If you have any further trepidation, I'll bet you have a friend/neighbor/relative that would gladly help you regain full use of your instrument.

 

[Matt Liebenau]

View attachment 7293488
This is straight from A-zon's product image. $15 - I think you can get the concept a bit better from this image. It's simply called a "Woodriver Single Screw Extractor". As you can see at the lower right- this will be the end result. To get started, grab a scrap of wood and bore to about the outer diameter of the above extractor. This way, you have a collar to control the hollow tube saw, which otherwise would wander all over on you since there's no center point to guide it. Then, simply stab in a dowel of the right size, cut flush. Set your bridge with the good screws, use the hole in the bridge to mark/punch dead center, drill a small pilot and voila- like it never happened.

Good luck. If you have any further trepidation, I'll bet you have a friend/neighbor/relative that would gladly help you regain full use of your instrument.

Those screw extractors are available in the US at places like Woodcraft and Rockler woodworking. Amazon probably has them. You’ll just need to figure out what size you need.

 

[gidbass]

I've had better luck removing broken bolts/screws with a left handled drill bit.

Good Luck!

 

[C Stone]

Sure seem like excessively long bridge screws but at any rate you could use a wood driver screw extractor then glue plug and fill for a proper fix but if it were mine I would simply enough glue and plug the broken hole then use a shorter screw in that hole when reattaching the bridge.

 

[J-Bass RMR]

I’ve never had luck with the screw extractors, but give it a try if you can find the right size.

And your awful close to the backside of the bridge for the hole to be covered up if you use a "plug cutters".
I'm guessing if that's a #6 screw, it's close to .15" O.D.

I’d just use a small bit to (slowly) drill around the sides and "top"-side of the broken screw – but not toward the backside of the bridge -
maybe even put a piece of masking tape, up against the edge where the bridge would be, for a guide.
You might drill a larger hole in front of the screw– work it loose and have room to grip it with a mini needle nose.
It may get a bit "ugly", but hopefully it all gets covered up. Use appropriate size dowel to plug the hole(s).
Amber super glue would be a nice finishing touch.

Re-install the bridge with screws in the outside holes and drill your pilot hole. A Vix bit works well for this.

 

[rickwrench]

Edit: You could try to drill out the screw, but the dill will most likely wander off into the wood.

Perfection being the enemy of good enough...

This probably won't be very popular as a solution:
Looks pretty deep in the hole? If it was a bass I was keeping for myself, I'd try to drill it first. Preferably with a drill press but a block guide will do, too. If it wanders, so be it. Call it good and accept that the new screw won't be in 90˚ straight. You'll have one oval head that is slightly askew, but it will be obscured under the the saddles and intonation screws.

If you're fixing to sell -> core and dowel.

Whatever you decide to do, screw in the wonky holed screw last.
And, definitely get some butcher block wax (or beeswax, paraffin, etc.) for all the screws before they go back in. Wax, not soap. Soap attracts moisture.

 

[Philonius]

Core drill, preferably in a drill press. E-Z out type extractors are just going to make a mess.

 

[Turnaround]

Those screw extractors are available in the US at places like Woodcraft and Rockler woodworking. Amazon probably has them. You’ll just need to figure out what size you need.

But then you beed to drill a hole down the centre of the broken screw shaft to take the extractor. Not an easy task on a small diameter screw buried in the wood.

 

[Zooberwerx]

I've fabricated extractors from thin-walled brass tube (...available from on-line hobby sites)....ID should roughly approximate the stub's thread OD. Cut some teeth with a file or Dremel cut-off wheel. Chuck-it-up in an electric drill set in reverse. Ideally, the extractor will "grab" the remnant and back it out.

Riis

 

[Matt Liebenau]

But then you beed to drill a hole down the centre of the broken screw shaft to take the extractor. Not an easy task on a small diameter screw buried in the wood.

I meant the core drill type extractors pictured in post #8. Should have been more specific. An EZout type extractor would be towards the bottom of my list in wood. I have had good luck with left handed bits although you run into the same problem with needing to hit more or less the center of the old screw and its in there pretty deep.

 

[Pep]

View attachment 7293428

I’m in the process of “restoring” (no pro here) a 1979 Yamaha Pulser Bass. Finished the cleaning and fixing minor issues I was re-assembling the bridge an one of the 5 screws has broken inside the hole (electric screwdriver just for the initial turns, then hand screwdriver to avoid to tighten too much, but…not enough grace for a 40 year old screw maybe….).
What am I gonna do now?

First of all, when installing screws that are tight, back it out and use either candle wax or bar soap on the threads. Also it’s best to use a manual screw driver. Ask me how I know.

 

[Gorilla Monsoon]

The break looks even enough to use a 5/32” left hand drill bit. It would REALLY help if you have access to a drill press. If not, use a variable speed drill, start slowly. This doesn’t look promising. Try a few drops of Sili-Kroil or even WD-40. Let it sit overnight. Id rather remove a broken screw from metal than a wooden substrate. The screw likely broke as a result of over-tightening; it was probably fatigued and weakened before you attempted to remove it. This is from Manhattan Supply Company.

 

[scuzzy]

I'm lazy, I say leave it and just mount with 4. Many only use 3.

Aside from that, screw extraction. More work, but more thorough.