How-To Fix a Cracked Fingerboard?

[CryptCaster]

One of my guitars has developed a noticeable crack in the neck/fingerboard (all one piece maple neck and fingerboard) down at the low-E string side 21st and 20th fret. I'll get a picture added soon (update: pic added here and on third post in thread). Just curious about fixing it.

I've heard I should/could fill the crack with super glue with maple wood dust, then sand it flush. I wonder if there's a way to do it without removing the fret wire. I don't know... I'm just spinning my wheels here. Insight, please!

 

[Peegoo]

@CryptCaster

It's probably cosmetic and not structural, but it's a good idea to get it repaired before moisture gets into the wood through the crack and makes it worse. The longer it goes in its current state, the harder it is to make an invisible repair.

We cannot recommend a fix until we see the damage. Anything else is guessing.

 

[CryptCaster]

@CryptCaster

It's probably cosmetic and not structural, but it's a good idea to get it repaired before moisture gets into the wood through the crack and makes it worse. The longer it goes in its current state, the harder it is to make an invisible repair.

We cannot recommend a fix until we see the damage. Anything else is guessing.

Fair point. I was hasty to post, but I texted my wife and asked her to send a pic so I could update and here it is:

 

[Peegoo]

@CryptCaster

That looks like someone forced a screw into the neck when mounting it--into a hole drilled too small or not deep enough.

The fix for that is

1. Completely remove the neck.

2. Force Titebond II into the crack. You do this by putting several drops in the crack and pressing it in with your fingertip. Do not attempt to push the glue in with a screwdriver, knife, or anything else because if you displace any wood fibers in there, the crack will not close cleanly.

3. Apply a large bar clamp across the neck to pull the crack closed. Just enough pressure to pull it closed.

4. While in the clamp, wipe off all squeezed-out glue with a slightly damp rag and cotton swabs. Wipe it dry and allow it to sit overnight before removing the clamp.

 

[Peegoo]

@CryptCaster The clamp goes on like this:

 

[CryptCaster]

Awesome, I will give it a go! Thank you!!

 

[eallen]

Peegoo has it +1

 

[BFcaster]

Yeah, Titebond or Elmer's, not super glue. super glue will not get into the wood.

 

[Boreas]

Agree with @Peegoo. Just be careful. After you remove the neck, you may want to try to close the crack without glue and with finger pressure to see what kind of resistance you get from the frets. I wouldn't expect them to be a problem, but you don't want to jam the wood against the fret without lining it up first or you could unseat the fret or chip out the edge of the "fretboard" area if the fret isn't lined up just right. If it looks like the broken wood will slide easily into place, then go ahead and glue and clamp.

 

[Ed Storer]

You might want to check the holes & screws for the neck for length/depth and diameters. Just reattaching the neck with the same screw is likely to undo your repair.

 

[hopdybob]

and put a piece of backing paper between the clamp on the side were the glue is.
this to prevent tear out wood when removing the clamp.
and certainly would check the neck cave if there enough room to remount the neck.
this problem did not happen by just looking at it

 

[Peegoo]

and put a piece of backing paper between the clamp on the side were the glue is.
this to prevent tear out wood when removing the clamp.

This certainly applies if using a wooden screw clamp.

But when using bar clamps like this one that have the soft elastomer pad on each jaw, the glue does not stick to the clamp. They release cleanly.

 

[hopdybob]

This certainly applies if using a wooden screw clamp.

But when using bar clamps like this one that have the soft elastomer pad on each jaw, the glue does not stick to the clamp. They release cleanly.

aha, good to know because i only have metal clamps.
maybe they would not bond with the wood, but i use wood blocks to spread the clamping force, and then use the backing paper

 

[Peegoo]

@hopdybob

I know you mean wax paper. Others here may not, so I'm mentioning it

 

[CryptCaster]

Much appreciation to all who've contributed. The repair is underway with some Titebond II and a small piece of wax paper between the clamp and neck on the cracked side just to be safe. Gonna let it sit for a full day and try to reattach it tomorrow evening.

 

[dsutton24]

While you're waiting for the glue to cure it might be worthwhile to contemplate why it cracked in the first place. It's possible that the pilot holes for the neck screws are too small in diameter, or they didn't go deeply enough. While you're there make sure the holes in the body are big enough that the neck screws pass through easily.

 

[CryptCaster]

While you're waiting for the glue to cure it might be worthwhile to contemplate why it cracked in the first place. It's possible that the pilot holes for the neck screws are too small in diameter, or they didn't go deeply enough. While you're there make sure the holes in the body are big enough that the neck screws pass through easily.

Yeah, I've been giving that a lot of thought and I'm sure I had something to do with it. I had taken the neck off a couple weeks ago to change out the neck plate. I thought I'd put it back on really well and I've been playing on it since then without any problem. The other day I picked it up to play on it some more and that's when I noticed the crack. When I took the neck off to fix it today, I noticed that I must have missed the bottom left mounting hole when I put it back on and forced a new one (So there are now 5 mounting holes in the heel). I'm sure that is a BIG part of why this happened. What's got me stumped is why it took a couple weeks to actually crack tho... but that's probably here nor there. I need to be more careful when I reattach it this time.

 

[DrASATele]

I can tell you why... time. I live in MA and the humidity has been swinging up and down in this area for a few weeks. There's been enough of that to turn a small crack that you can't see into one that you can. I'd plug the offending hole with wood or saw dust just so humidity or anything else doesn't cause another issue down the road.

 

[old_picker]

I'd be doweling that odd hole once the glue in the crack has gone off properly - best to go in with the screws by hand for the first few threads to ensure you have hit the hole. It must have taken a lot of pressure to force that fifth hole unpiloted into hard maple.

 

[Sea Devil]

I love both of the customized clamp labels! The repair looks fine, even with that shadow in the photo. Titebond is perfect for this.