worn screwholes

[air_leech]

I purchased a bass that has a worn screw hole for one of it's P pickup screws.
the problem is that I can only set it low or otherwise the screw wont hold.

whats the best filler to repair worn screwholes?

Thanks,
Elad.

[Tactician]

You'll never really sort it as the grain on a plug will go virtical and the surrounding wood will be flat. A matchstick put in the hole will give you a quick fix - but beware of the finish cracking around the hole as you might not get the screw started in the hole centre and pressure against the hole side will crack the varnish if it's brittle. Again fill it with too much matchstick and the screw won't turn as the body wood can be so hard. These idaes at best are emergency fixes when out on the road.

Best info would be in Dan Erlwine's book on Guitar repairs. In that he refers to repairing the screw holes in the neck joint by drilling out the hole to allow the insertion of a dowel and then redrilling the pilot hole. You'd have to be into repairing your guitar regularly to try this though. It's an easy job a good luthier, but risky if you're doing it for the first time on your own pride and joy bass!

[202dy]

The simplest way to do this repair is with super glue.

Basic concept: The original hole is drilled to roughly the diameter of the shaft of the screw. The shaft diameter is smaller than the thread diameter. When the screw is installed in the hole it compresses the wood around it to form threads. The idea is to coat the threads in the wood with super glue.

Tools needed:

Liquid thin super glue
plastic toothpick or small diameter rod

Pour some super glue into a small disposable container. Use a plastic toothpick, an old piece of guitar string, or something similar and coat it with liquid. Run the new tool around the inside of the hole. Make sure you get it to the bottom. Give it a minute or so to harden and repeat. Four or five times should build up enough of a wall to rethread the screw. Then run the screw in slowly. It may be a little tight. That's o.k. Be sure it goes in at the right angle to the body or it will pinch the pick up when you reinstall.

When putting the pickup screws back in their holes always turn the screw the wrong way first. Do this gently and you will feel it click or bump. That happens when the beginning of the threads on the screw find the beginning of the threads in the hole. As soon as you feel it reverse the direction and install the screw. This will prevent stripping out the threads in the wood or your newly formed super glue threads.

[Scott in Dallas]

Sharp wooden toothpicks are great temporarily. T-nuts or threaded inserts would work well for pickup screws IMO.

[pkr2]

Toothpicks, superglue and such are fine to repair a stripped pup screw or a pickguard srew but should never be used for a critical connection like the bridge, neckbolts and strap buttons. The toothpicks create an endgrain problem common to woodscrews.

Woodscrew threads lose a lot of thier holding power when used in endgrain applications. Not to mention the fact that the first time the screw is removed and replaced without aligning the threads, the walls of the screw hole are practically destroyed. By the way, 202, that was a good tip on avoiding that problem.

You can repair a screw hole to it's original strength and exceed the original strength on the upper horn strap button. What I suggest takes less than 3 minutes from start to finish.

First get a 1/4" plug cutter. They can be found at almost any hdwr store. Black and Decker sell one that works perfectly well for less than $5.00

Cut a plug with the plugcutter from a piece of scrap wood, cotting the plug across the grain. Now, using a 1/4' drill bit, open the hole up and glue the plug in. Use a sharp pocket knife to level the plug with the surface and redrill the pilot hole. If everything is kept reasonably centered, the screw head/hardware conceals the repair.

I align the grain of the plug 90 degrees to the grain of the wood simply because I always have

Now, intead of shearing wood, the screw is wedging its threads in the cross grain. It self aligns pretty much on reinsertion and is not compromised if the screw cuts new threads. Self healing you could say.

Then too, there are woods that just dont hold a screw well, no matter the grain orientation. Red cedar comes to mind.By inserting a plug made from a harder wood like ash or hickory a lot more torque can be put on the screw.

You can gain a lot of the advantages of a metal insert but still maintain a wood to wood connection. You decide if that's a tonal consideration. lol

IMHO

[emils]

Since this is only a pickup screw I would just use a toothpick trick. Don't use any glue and just let the screw compress the toothpick, there will be enough resistance there to handle the puling power of the pickup spring. IMO anything else is a bit of an overkill.

[Tactician]

Emils - watch this one though. I've tried bigger screws, and off centre screws when using this repair trick, and they nearly always crack the varnish and you end up with chipped screw hole edges. Not a problem of the hole is hidden but it could chip out beyond a pickguard edge and be very unsightly. There used to be a fibre hole filler for use instead of a plastic or wooden plug - that would work fine if it's still avaiable. Just be careful of the tooth-pick, match-stick trick as it's not really a professional way to fix the problem.

[joeyl]

Originally Posted by pkr2

First get a 1/4" plug cutter. They can be found at almost any hdwr store. Black and Decker sell one that works perfectly well for less than $5.00

I used some maple dowels to fill holes in my neck because they did not align with the stewmac body I was given. It is a very strong method, it's been ten years now, and still holding strongs

[pkr2]

Originally Posted by joeyl

I used some maple dowels to fill holes in my neck because they did not align with the stewmac body I was given. It is a very strong method, it's been ten years now, and still holding strongs

Well I guess that pretty much blows what I posted out of the water. lol
Using a dowel is threading into end grain. It may hold forever in your case. I've seen toothpicks hold a neck screw before. It's still not the right way to repair a screw hole for maximum strength.

Basically, if you're satisfied with a amateur method of repair, the quick and dirty way is the way to go. It works nearly every time and if it only holds up a few months, it's ok.

If the instrument is a gigging instrument and a screw comes loose in the wrong place in the middle of a set/song, you'll wish you'd taken the time to do it right.
The rough and tumble handling of an instrument in gigging calls for the strongest repair that you can reasonably make.

Just for the sake of discussion, of course.

[emils]

Originally Posted by Tactician

Emils - watch this one though. I've tried bigger screws, and off centre screws when using this repair trick, and they nearly always crack the varnish and you end up with chipped screw hole edges. Not a problem of the hole is hidden but it could chip out beyond a pickguard edge and be very unsightly. There used to be a fibre hole filler for use instead of a plastic or wooden plug - that would work fine if it's still avaiable. Just be careful of the tooth-pick, match-stick trick as it's not really a professional way to fix the problem.

Hmmm, it's a P bass pickup screw in the OP's case, the screw is screwed into the bottom of the rout under the pick guard, I realy doubt that any finish will be chipping. I just think that we are over-engineering the solution, I can see the point in using dovels in a more critical joint on the bass but not on the pickup screw.
Also machstick is not as strong as toothpick in this aplication.
I have also succesfully used an offcut from a used ballpoint pen refill for stripped pickup screw holes. Cut to size, drop of superglue in the hole, push the pen refil in and you get perfectly centered hole that is just as strong as wood.

[pkr2]

Originally Posted by air_leech

I purchased a bass that has a worn screw hole for one of it's P pickup screws.
the problem is that I can only set it low or otherwise the screw wont hold.

whats the best filler to repair worn screwholes?

Thanks,
Elad.

I hope it's OK to answer the same post twice.

"I purchased a bass that has a worn screw hole for one of it's P pickup screws.
the problem is that I can only set it low or otherwise the screw wont hold."

Well, Elad, I would look at it from this angle: The screw was put into a new hole of the proper size and was tightened properly when the bass was built. However, the screw connection failed anyway and the pup came loose.

Now, you have three choices,. You can repair it and end up with an equal repair, a stronger repair or a weaker repair.

The original, brand new connection in brand new wood failed. Why would you want to repair it to the same longevity standards as the original if the original method failed?

A better question is: why would you want to repair it to a lower standard by screwing into the end grain of a plug or wedging the screw in with toothpicks?

If your bass has a softer wood as a body material, chosen by the builder because of its light weight, its not going to grip a screw like a harder or stringier grain wood will. Especially on the small diameter pup screws. A wooden plug can just a well be made from a wood that has the best screw holding ability, such as ash or hickory or any long grained wood. Pup screws are notorious for coming loose.


"whats the best filler to repair worn screwholes?"
Brand new wood with the proper grain orientation.

The truth is, all of our methods will work and it's not the end of the world if a pup screw comes loose. Simply put a toothpick in and replace the screw. It very well may last as long as you own the bass. It may very well not last long at all and you may have to repeat the process sooner or later.

If you are a gigging musician, you may want to look at a more permanent repair.

I'm sure that all of us are adult enough to keep a good discussion on an even keel.

Emil, you can consider the tip with the ballpoint refill stolen! lol

[emils]

Originally Posted by pkr2

Emil, you can consider the tip with the ballpoint refill stolen! lol

It's not my idea, you use a plastic plug to screw something into the concrete wall don't you. That's where I got it from.

[air_leech]

thanks guys, these are all good advice and I'll either go with the pen refil plug or the superglue solution.

Pkr2, regarding your second reply- the first time around didnt fail because the manufacturer was slopy, it failed because the bass has been through 18 years of use and apperantly it's former owner(s) werent as careful as I am with my instruments.
btw, the pup is mounted to maple body wood, I believe its denser than ash.

thats aside the toothpick solution doesnt sound like a serious solution for me, maybe if I had a gig and had to fix the bass in a few hours to make it, but not as the long term solution.

anyway thanks all, I'll let you know which one worked for me for the intrest of anyone who faces the same problem in the future.

Elad.

[tplyons]

Dan Erlewine did this exact thing in Guitar Player Mag last month... a small piece of wood veneer, rolled up. Should at least give the threads something to grip to.