Stuck intonation screw -- advice?

[Nedmundo]

I tried to adjust the intonation on my L-1500 last night, and almost completely stripped the screw, which is stuck inside the saddle itself. I've dabbed some WD-40 in there, and I'm letting it soak in. The screw isn't completely stripped. I can still get a small slot-head screwdriver in there, so if it loosens up I should be able to remove the screw.

Any other tips?

I've already ordered new screws as recommended in another thread, so if get this screw out I should be good.

Thanks!

[Ken Baker]

Originally Posted by Nedmundo

I tried to adjust the intonation on my L-1500 last night, and almost completely stripped the screw, which is stuck inside the saddle itself. I've dabbed some WD-40 in there, and I'm letting it soak in. The screw isn't completely stripped. I can still get a small slot-head screwdriver in there, so if it loosens up I should be able to remove the screw.

Any other tips?

I've already ordered new screws as recommended in another thread, so if get this screw out I should be good.

Thanks!

Ouch!

So you've got the screw threads frozen in the saddle (or over-driven into the saddle) and the phillips head stripped out?

Here's how I'd handle it:

1. De-string the bass and remove the bridge.

2. Using a Dremel with a Carborundum wheel, cut the offending screw as close to the bridge back plate as possible.

3. Clamp the saddle down and lock Vise Grips on the screw and attempt to back it out.

4. Optionally clean up the saddle threads with a tap.

5. Re-assemble.

Ken...

[Nedmundo]

Thanks, Ken. I let it soak in the WD-40 for several hours, but that screw wasn't going to move, so I realized I needed to cut it somehow. Your approach would definitely work.

Unfortunately, I don't have access to a Dremel tool, but I do have a set of drill bits for going through metal. I selected a bit slightly wider than the screw shaft, and simply drilled off the head. Since the screw head wasn't completely stripped, it was easy to center the bit; otherwise this would have been dicey. With my left hand, I pushed the saddle back into the bridge to expose the screw head and avoid drilling into the bridge. Luckily, it worked.

I removed the screw shaft from the saddle with vise-grips, but man, it was really stuck. It took lots of torque to get it out of there. After it was out, I threaded a machine screw of the right size into the saddle, and it met resistance after just a few turns. If I had pushed it, that screw would have gotten stuck too.

So I think I need to clean the saddle threads as you suggest.
By a "tap" do just mean a screw of the right size, or is that something designed for this purpose? (I used to work for contractors, so I should know this, but so it goes...) Also, do you recommend any lubrication for this? Maybe I should just soak the saddle in WD-40 for awhile, and then thread a screw in and out a few times.

Thanks again!

[Ken Baker]

Originally Posted by Nedmundo

So I think I need to clean the saddle threads as you suggest.

By a "tap" do just mean a screw of the right size, or is that something designed for this purpose? (I used to work for contractors, so I should know this, but so it goes...)

A tap is a purpose-designed device that is used to cut new threads in an appropriately-sized hole. They are also useful for cleaning up threads that are screwed up. You can find them in good hardware stores, like a neighborhood Ace Hardware Store. Be sure to lubricate the tap as you work it with light machine oil. Marvel Mystery Oil works well here. Pretty much anything along the lines of classic sewing machine oil is fine.

Unless the bass is new, you should need an 8-32 sized tap. Take an intonation screw along with you for sizing if you decide to buy a tap. You might also consider replacing all your intonation screws with Allen head style.

Also, do you recommend any lubrication for this? Maybe I should just soak the saddle in WD-40 for awhile, and then thread a screw in and out a few times.

Thanks again!

Well, metal isn't going to soak anything up, so don't bother. Blow any crud and shavings out with a can of air using the long tube the give you. Then use a tap. Another screw might work, but a tap is made for the job.

Also, WD40 is a penetrant and water displacer; not a lubricant. It can be helpful "unfreezing" locked parts and cleaning gunked-up parts, but it's a lousy oil.

I think I'd keep them dry if at all possible. There isn't a lot of tension on the screws and they can vibrate out pretty easily, so why lube them and make that easier? If you keep the screws and saddles fairly clean and rust free, you'll be able to use them dry.

Ken...

[Nedmundo]

Thanks, that's very helpful. I'm off to the hardware store now for a tap, because no doubt this needs cleaning. I did order stainless allen screws to replace the originals.