I Can't Believe This Happend AGAIN!

[Atshen]

Anyway, the solution is to drill out the old holes then plug the holes with wooden plugs of the same diameter. Re-drill screw holes and reinstall bridge with better grade screws.

Use maple plugs. If your bass body is softer wood like basswood, installing hardwood plugs should eliminate the problem for good.

Edit: I forgot, secure the plugs in the hole with wood glue and make sure they don't interfere with the bridge's mounting surface!

 

[PortlandBass77]

Whelp this settles it, not buy a Spector anytime soon (not as if I was ever GASing for one to begin with) there are so many quality bass manufactures now that if one can't manage to design a bridge well then they not worth my time and money. Hell, even the import counterfeits have higher quality bridges....

 

[Fishheadjoe]

Try a a cotton ball then... if they are being scored by burrs in the bridge holes, that certainly will weaken the screws...
Again, probably not the answer, but it would be nice to eliminate that from your potential concerns.
Fishheadjoe

 

[Atshen]

Try a a cotton ball then... if they are being scored by burrs in the bridge holes, that certainly will weaken the screws...

If this was the problem, I think the screws would've broken just below the head...

 

[Facu.DSR]

Dude, I can't imagine the look of pain on your face when you saw it hitting the ground in front of you ; it gives me the creeps just by thinking about my bass falling

I hope you were able to fix it, but if that's not the case I would reccommend you taking it to a trustful luthier, it's such a delicate instrument !

ps. Just in case, in the future leave your bass on top of your bed or somewhere with a carpet ! lol

 

[Bassbubble11]

I think it might be the situation where the screws are breaking when they're being installed. Possibly from over tightening. That leaves only the top few screw threads, rather than the entire screw, holding the bridge in place. You'll run into that in furniture making sometimes. Especially when using long joining screws or when installing hinges. There's a dense spot somewhere in the wood (most often tight grain or a hidden knot, or occasionally even an epoxy or other glue line) that the tip of the screw penetrates but grabs onto very firmly. If you tighten the screw too much once it hits that spot, it will still rotate (because the metal still has some give) and give the impression you're still tightening it, but actually snap somewhere along the thread length and leave you with only a quarter or a third worth of screw actually holding things in place.

I touched on this earlier. I hope the OP read your post because it is the only logical answer.

 

[leemelone]

Dude, I can't imagine the look of pain on your face when you saw it hitting the ground in front of you ; it gives me the creeps just by thinking about my bass falling

I hope you were able to fix it, but if that's not the case I would reccommend you taking it to a trustful luthier, it's such a delicate instrument !

ps. Just in case, in the future leave your bass on top of your bed or somewhere with a carpet ! lol

It was siting in a stand both times the screws broke and never fell but thanks!

 

[JoeWPgh]

Over tightening a screw would not result in this kind of breakage. Typically when a screw is over tightened, the head snaps off.

 

[Bassbubble11]

Over tightening a screw would not result in this kind of breakage. Typically when a screw is over tightened, the head snaps off.

Wrong. You have no idea what you are talking about.

 

[howlin]

I haven't read through the whole thread but this could be the beginning of a whole new way to mount guitar bridge.

Find yourself the appropriate length of Chicago Screws and drill all the way through the body. Attach the bridge with the Chicago Screws and, hopefully, be done with it. And don't listen to all the nay-sayers those frothing at the mouth over such blasphemous treatment of an instrument. Just get the obe done and move on . . .

 

[leemelone]

40Hz said: ↑
I think it might be the situation where the screws are breaking when they're being installed. Possibly from over tightening. That leaves only the top few screw threads, rather than the entire screw, holding the bridge in place. You'll run into that in furniture making sometimes. Especially when using long joining screws or when installing hinges. There's a dense spot somewhere in the wood (most often tight grain or a hidden knot, or occasionally even an epoxy or other glue line) that the tip of the screw penetrates but grabs onto very firmly. If you tighten the screw too much once it hits that spot, it will still rotate (because the metal still has some give) and give the impression you're still tightening it, but actually snap somewhere along the thread length and leave you with only a quarter or a third worth of screw actually holding things in place.

I touched on this earlier. I hope the OP read your post because it is the only logical answer.

I've said this several times before but I guess I wasn't clear enough so I"ll state it once again. When I installed the replacement screws, I put some wax on the threads and used a screw driver to hand tighten them until they were snug. At no time did I over torque them.

 

[JoeWPgh]

Wrong. You have no idea what you are talking about.

Chill dude. You have no idea what I do. I go through thousands of screws in a year. So let me clue you in to how they actually work. Screws are a very good mechanical attaching device when they are in compression, which is to say tightened. They lose an astonishing amount of that strength when they are loose. In this case they will bend and snap somewhere along their length, as is the case with these screws. And as I said, on an over tightened screw the head typically snaps off. This is the result of the stress put against the head as it tries to push through the material it is meant to secure.

 

[JustForSport]

Look at the length of the first broken-off screws. After they broke, there are no threads in the holes that far in.

Look at the length of the second broken-off screws. After they broke, there are no threads in the holes that far in.

Screws that have an un-threaded section have no threads to help hold between the head and the beginning of the treads.

Zink-plated screws are not real s/s screws.

I would drill and plug (not with dowel/ end grain) with maple plugs, and drill pilot holes before waxing full-length screws to insert. Automotive sheet metal screws are stronger than typical wood screws, but finding flatheads may be difficult. High quality s/s full-threaded screws will permanently fix it.

 

[Bassbubble11]

Chill dude. You have no idea what I do. I go through thousands of screws in a year. So let me clue you in to how they actually work. Screws are a very good mechanical attaching device when they are in compression, which is to say tightened. They lose an astonishing amount of that strength when they are loose. In this case they will bend and snap somewhere along their length, as is the case with these screws. And as I said, on an over tightened screw the head typically snaps off. This is the result of the stress put against the head as it tries to push through the material it is meant to secure.

Dude, I am chill. You made a general statment that just isn't true. It is true that "sometimes" when a screw is over tightened it will break at the head but not all the time. Some screws are cheaper than other so what also happens is as they are being screwed into the wood they slightly twist and loose strength. Also if you read 40Hz's reply he talks about dense spots in the wood. The dense spot in this particular situation could be that the pilot holes were not drilled to depth those causing strain on the screw.

 

[Roland GR 88]

Good answers here but I'd go with Mugre on this one. The originals lasted 26yrs, the Home Depots 26 weeks. That's about right for a cheapo Chinese made wood screw. If I were you I'd install threaded inserts and machine screws and never worry again. It's not hard to do or very expensive if you source it out. Good luck

 

[tbz]

Or a bad batch of bass.

The bass in question was built in the 80s during a period in which Spector was owned by Kramer.

They did dicey stuff to cut costs, so that is a possibility.

That being said, and despite the fact that this bass is NOT covered by the Spector warranty (as again, it was technically built by Kramer when the current company owners no longer had any involvement with the Spector brand) I know the Spector guys tried to assist this gentleman earlier.

As-is it's a bummer, but as this is a 30ish year old bass, manufactured by Kramer during their downturn, these problems will occur.

 

[tbz]

Whelp this settles it, not buy a Spector anytime soon (not as if I was ever GASing for one to begin with) there are so many quality bass manufactures now that if one can't manage to design a bridge well then they not worth my time and money. Hell, even the import counterfeits have higher quality bridges....

See my post above, if this wasn't a troll comment. (Not saying it was, but....)

This was manufactured in the 80s by Kramer when they owned Spector. They really are not anything like a modern NS2, in terms of build quality, attention to detail, etc.

 

[Lo-E]

The original screws are counter sunk flat head and an oval head would interfere with movement of the saddles.

My bad; flat heads it is! I'd still go SS, though.

 

[tbz]

About six months ago I woke up one morning to find the bridge on my Spector NS2 laying on the floor because the three screws holding it on failed and broke. You can see the original thread I posted here:

How To Safely Remove Broken Bridge Screws? | TalkBass.com

I was able to safely drill out the screws without making the holes any bigger. I replaced the screws and they tightened down snugly using a screw driver. Problem solved.
So I'm sitting here today eating my lunch when all of a sudden I hear a thwack! and look over to see the bridge pop off again right in front of me! The new f*%#ing screws broke off again! I owned 15-20 basses over the years and I've never seen or heard of this happening to any other bass even once. Let alone twice! ***!
View attachment 704932 View attachment 704934

So you repaired a broken instrument yourself, improperly and it broke again?

Shocking.

There's definitely some good advice here on how and why that repair would not take.

It is a bummer that you do not mention anywhere that Spector tried to help you with this off-warranty, but was not able to, as again, its 30 years old.

I personally would just take it to someone that knows how to fix it, and spend the $50 to prevent it from happening again.

 

[96tbird]

So much wrong in here.

Screws can't break that far down if there is solid wood at the top of the hole.

The wood at the top is shot. OP didn't detect this on first repair.

The strings pull the bridge screws toward the neck. The screws move (bend) in the soft top of the holes creating a stress point where they broke. They broke at the point of anchorage: where solid wood began.

This has nothing to do with bridge design.....

...it has to do with whoever installed or re-installed the original screws at some point. THEY damaged the holes.

This is metal stress caused by the bending of the screws at half length and the continual stress working away at them for years and then again several months. True that the screws used by OP were probably junky.