How would you fix this?

[samcatluth]

I had a similar situation with an old Yamaha L-10 (solid top). Here is what I did.
1) I bought it from a vendor in New Mexico so I assumed it needed humidification so I let it sit in my guitar room at 50% humidity for 2 weeks. The crack improved visually after that. Note I use my guitars and keep them at 50% humidity year round.
2. I used wet 2000 grit sandpaper to take off the ridges of the separation. If you have not done this before don't do it on your prized guitar. It is something you get the feel for as far as how much and how much pressure to use. You take a swipe, feel the crack, look at it under magnification, take a swipe, feel the crack and over and over until it is smooth. Remember you can always take more off..not so easy putting back on.
3. I used Meguiar's X to smooth out the finish followed by Turtle wax swirl remover. Again, this will take a couple of hours if done right. You have to go SLOW.
4. Now the crack is much less visible. More importantly it is smooth to the touch. Reducing the ridge of the crack reduces the angle reflexion of light as it hits the top reducing the shadow.

good luck with it..Jeff B.

[charles Tauber]

Originally Posted by samcatluth

I had a similar situation with an old Yamaha L-10 (solid top). Here is what I did.
1) I bought it from a vendor in New Mexico so I assumed it needed humidification so I let it sit in my guitar room at 50% humidity for 2 weeks. The crack improved visually after that. Note I use my guitars and keep them at 50% humidity year round.
2. I used wet 2000 grit sandpaper to take off the ridges of the separation. If you have not done this before don't do it on your prized guitar. It is something you get the feel for as far as how much and how much pressure to use. You take a swipe, feel the crack, look at it under magnification, take a swipe, feel the crack and over and over until it is smooth. Remember you can always take more off..not so easy putting back on.
3. I used Meguiar's X to smooth out the finish followed by Turtle wax swirl remover. Again, this will take a couple of hours if done right. You have to go SLOW.
4. Now the crack is much less visible. More importantly it is smooth to the touch. Reducing the ridge of the crack reduces the angle reflexion of light as it hits the top reducing the shadow.

good luck with it..Jeff B.

Touching-up the finish - to level it with the surrounding surface - so that the crack in the finish disappears is a separate operation from repairing the crack in the wood.

If you choose to do any sort of finish work, repair the crack first, so as not to contaminate the gluing surfaces of the wood with finish, waxes, etc.

[samcatluth]

I know that. I suggested a course of action that is not likely to get screwed up. Gluing is a different story. Often cracks if they are stable can be lived with. Jeff B

[charles Tauber]

Originally Posted by samcatluth

I know that.

You do, but will novices reading what you wrote know?

[murrayatuptown]

What about fish glue is 'forgiving'? Does that mean longer working time, or maybe not as brittle as some adhesives?

Thanks

Murray

[redir]

Originally Posted by murrayatuptown

What about fish glue is 'forgiving'? Does that mean longer working time, or maybe not as brittle as some adhesives?

Thanks

Murray

Longer work time and ease of clean up.

===

Without getting into personal arguments it's suffice to say that there is many ways to skin a cat and in the 20 plus years that I have been doing this I have never had a dissatisfied customer, nor have I ever had a guitar that I repaired come back to be re-repaired, long list of reasons not withstanding.

None the less as you can see these sorts of things are complicated and really almost pointless to argue or offer advice without actually seeing it, it's best left to some one with experience to deal with.