Is there a way to make glue adhere to wood with closed pores? (Guitar repair question

[Mr. Lahey]

I have a guitar I have had for about 12 years that has just been sitting in the attic. About 10 years ago, the top part of the neck on the back started to separate. Not knowing what I was doing, I tried pushing some epoxy into the crack and clamping it to repair it.

My repair job didn't work, and later I took it to a luthier. He stated that the epoxy I had used had filled in the pores of the wood, so there was no way it could be repaired because any adhesive would not hold.

Now that I'm into woodworking I thought maybe I would look into fixing it. I was hoping that if I did it properly by removing the fret board and dissembling it and preparing the surface, I might have a way to get it to work. I have no idea how to remove a fret board though. Any ideas?

 

[CarvedTones]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

This guy has the best tutorials (IMO) on this sort of thing:

http://www.frets.com/FRETSPages/Luthier/Technique/Guitar/Structural/NewFingerBoard/85hd28board.html

You will want to bookmark his "big index":

http://www.frets.com/FRETSPages/pagelist.html

Information for luthiers starts about half way down.

Interesting timing. A friend just asked me to look at a violin his wife had. She found it on the curb and could not understand why someone would thrown it out. I do - it's obviously because they don't have a fireplace. Anyway, I offered to try to fix it up anyway and the first thing I had to deal with was plate separation in the back. I planned to use hot hide glue, but found someone had attempted to fix it with CA, so I was faced with two choices - either a pretty extensive cleanup and full removal of the back or I could fix it again with CA, only more carefully so that it actually succeeded. This violin will double in value when I put new strings on it, so you can probably guess which choice I made.

What the luthier said is somewhat correct; in order to remove the epoxy you will end up removing a tiny bit of wood on the surface and hide glue won't hold until you have two clean perfectly mated surfaces. Tiny bits matter in luthery, as that will cause the nut and frets to be just that tiny bit closer to the bridge. But you can likely make an adjustment at the bridge to compensate.

 

[CarvedTones]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

A clarification - I did make a leap about what "glue" means in your title since you were quoting a luthier. With most luthiers I have talked or e-chatted with, "glue" without a qualification means hot hide glue. There are other adhesives that will stick to an epoxied surface. There are arguments all over the place about whether or not anything other than hide is suitable, better, worse or whatever. I won't wade into that, but one of the main reasons to use it is that the next guy will assume you did. Frank Ford's instructions to inject steam in the joint would have mixed and possibly disasterous results if there were something other than hide glue under that fingerboard.

 

[Mr. Lahey]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

Thanks! That website looks helpful.

 

[truckjohn]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

In this case a pic would be worthwhile...

From your description, it sounds like you are saying that the neck is separating from the body at the heel... but your description could also mean that the headstock or headstock veneer is coming loose....

Otherwise -- good luthiers can really do some amazing things... but it will cost some good money...

In the end, I am guessing that most of your decision will be made by the value of said instrument... If it's a Martin D28 -- It is probably worthwhile to pay someone to fix it right.... If it's a $99.00 Epiphone... probably not so much.

Thanks

John

 

[Mr. Lahey]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

Here is a pic

With alot of patience I managed to get the fretboard off. The surfaces were solidified with epoxy; I shaved it away with a chisel, then pitted and scored the surfaces for good measure.

However, due to the amount of wood I had to remove, there is a gap in the joint about the thickness of a credit card. Will the hide glue fill this gap or should I do something else?

 

[CarvedTones]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

Hide glue will not fill. Both surfaces need to be near perfect for hide.

The "right" answer is not a fun one. You may need a wood spacer. In other words get a perfect set of surfaces that would fit together and then glue in a very thin piece of hardwood to account for what you lost flattening. If you use a contrasting wood like ebony, it can look quite nice. Of course, it must be dead flat and of even thickness.

 

[CoolHandLuke]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

Man, your truss rod is showing

It's going to take some work and luck to get that one right.

 

[Mr. Lahey]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

I ended up using Gorilla Glue, which filled the gap and adhered just fine. Once I get some hide glue I will reattach the fret board.

 

[CarvedTones]

Re: Is there a way to make glue adhere to wood with closed pores? (Guitar repair ques

I ended up using Gorilla Glue, which filled the gap and adhered just fine. Once I get some hide glue I will reattach the fret board.

Yikes! I hope it mostly fit tight. Using PU to fill gaps is like using a marshmallow as a plug; the space is filled, but there is a lot of air. Slightly wet the surface of a piece of scrap and put a couple of drops of PU (Gorilla Glue) on it. After it puffs up and dries, cut into it.