how many times can a screw be screwed til the screwhole is just screwed?

topo morto · #1 02-03-2013, 05:43 PM

How many times can you unscrew a screw (e.g. bridge, neck joint) & screw it back in before it stops providing such a firm joint?

As the wood that the threads cut into gets more and more cut into and softened, surely this makes a difference? Either the bass is going to start sounding worse, or just fall apart...

unclebass · #2 02-03-2013, 07:18 PM

I would think that you could remove and replace screws many, many times if you are careful not to create new threads when you reinstall screws. When putting the screws back in place very gently turn the screwdriver until you feel the screw catch the threads already in the hole. If you start new threads several times in the same hole, any strength that the screw has in that hole will be removed due to the lack of material remaining. If you do find that you have screws stripping out, you can use toothpicks in the holes to help hold screws, but much better to never have that problem to start with.

202dy · #3 02-03-2013, 07:19 PM

Many times if it is done correctly every time.

The trick is to reverse the direction of the screw while starting it in the hole. This allows the start of the screw thread to find the start of the threads in the hole. That prevents cross threading which ruins the threads in the wood.

The wood does not become softer with use.

T_Bone_TL · #4 02-03-2013, 07:22 PM

^^ They write faster than I do.

Well, it makes more of a difference if you do it the wrong way.

If you backturn the screws when putting them in until you feel them drop into the threads that are already there, you don't cut new threads each time and they last a lot longer. Many people don't know that trick.

One time by a careless person can be too many (rip the threads right out by overtightening), I don't really know where the upper limit lies for a careful job, but it's fairly high, and when exceeded metal inserts can be used for more durable threads.

topo morto · #5 02-03-2013, 07:24 PM

I guess I always do the back-turn trick... you have to do it when screwing into metal so it's kind of a habit. Hmm. you all made be feel better so far!

musicman666 · #6 02-03-2013, 07:34 PM

Just twice.....anymore and it all goes to hell !!

abemo · #7 02-03-2013, 09:20 PM

As stated, depends on how you put them back in, if done correctly, with backturning, it should last forever. That said, if they're already stripped, the toothpick method, or a small dowel works well to repair it.

abemo · #8 02-03-2013, 10:18 PM

This thread should be called "how many times can a screw be screwed til the screwhole is just screwed"

topo morto · #9 02-04-2013, 02:37 AM

Quote:

Originally Posted by abemo

This thread should be called "how many times can a screw be screwed til the screwhole is just screwed"

now it is.

KarlK · #10 02-04-2013, 04:44 AM

Quote:

Originally Posted by abemo

This thread should be called "how many times can a screw be screwed til the screwhole is just screwed"

One time less than it can be unscrewed.

K

billgwx · #11 02-06-2013, 10:36 AM

Thanks for that tip! Will come in handy since I have to detach the neck to get at the truss rod on my basses.

sonic 7 · #12 02-06-2013, 04:46 PM

A drop of superglue into the hole , let it dry then screw the screw back in. Works well as do the toothpicks . Wood screws into wood were never intended to be taken in and out over and over its just a matter of time before you need the the toothicks . Some manufacturers use metal inserts for things like the control cavity cover.

JLS · #13 02-06-2013, 05:31 PM

Quote:

Originally Posted by billgwx

Thanks for that tip! Will come in handy since I have to detach the neck to get at the truss rod on my basses.

Consider threaded inserts & machine screws.

tbplayer59 · #14 02-07-2013, 11:14 AM

I knew this groupie back in the 80's, and her.... never mind.

Growly Lytes · #15 02-08-2013, 08:17 PM

Quote:

Originally Posted by topo morto

I guess I always do the back-turn trick... you have to do it when screwing into metal so it's kind of a habit.

Im in the same boat here !

Bassamatic · #16 02-08-2013, 08:53 PM

Turning it backwards gently until you catch the thread is not only advisable for wood, but for plastic as well. If you are careful about this, you can use the hole many times. It is also important not to over-tighten. For non-critical items, like pickguards, just until it touches is tight enough, for instance.

Liam76 · #17 02-08-2013, 09:18 PM

I have a maple jazz neck that has been on and off of four different basses over several years. Still tightens up nice and firm.

Only problem I've ever had with screws stripping was with a Mahogany body. I had the control cover off to shield it and stripped a thread. Then with the same guitar, one day I picked it up and a bridge pickup screw had just popped out for no reason. I just put bigger screws in to fix both.

curbowkid · #18 02-08-2013, 09:27 PM

It varries with the wood. Basswood strips out very easily. Next would be alder and mahogany, then ash and walnut, then woods like maple, wenge and ovankol which almost never strip. It has to do with the hardness. The softer it is the easier it will strip out. The best way i have found to fix or prevent it is drop super glue in the holes and let dry before putting the screw back in. The other is using a bigger screw but that has the same downfall as the original screw.