Remove first then glue or just glue and clamp???

[Ky Slim]

I know this isn't the best pic but the issue is visible: The back is coming unglued for about 3 to 4 inches back from where the neck joins the body.
Does the entire back need to come off first and then be reset and glued or can this just be glued and clamped?
I have little repair experience so any tips/ resources would be greatly appreciated. Also, this is a 1921 A2 that has already been repaired in several other spots. I don't think it has much collector value at this point so my goal is to get it playing well. I am considering some new bigger frets but this back situation has to be addressed first.

Thanks!

[HoGo]

I know this isn't the best pic but the issue is visible: The back is coming unglued for about 3 to 4 inches back from where the neck joins the body.
Does the entire back need to come off first and then be reset and glued or can this just be glued and clamped?
Thanks!

These old mandolins were glued with HHG so if there is NO previoys repair with other type of glue I'd just wash it with deionized water and glue back with fresh HHG. If it cannot be clamped tight together and in alignment, perhaps more thorough cleaning may be needed (but no wood removal) or slight further opening of the joint for better access ant it will allow slightly better alignment.
If other type of glue was used before you NEED to clean the old glue as thoroughly as possible. I'd glue it back again with HHG as it tends to hold best in these joints under constant stress.

[StuartGold]

Just curious..... What is that notch just under the heel plate?

[resophonic]

That back looks like it's been off before. The neck block is an unlikely place for the back on an old Gibson to slip away from the neck heel like that, there should be a small metal nail or spike from the neck block into the back. I suspect that the spike is gone from previous back removal. You should be able to look in the sound hole and see evidence of a re-glue if the back has been off in the past. Determining which glue was used will play a part in deciding how to proceed.

[Ky Slim]

Just curious..... What is that notch just under the heel plate?

It is missing a small piece of the inlay wood stripe that runs up the middle of the neck V . I'm not sure what kind of wood it is but it is a different color and texture than the neck.

[Ky Slim]

Determining which glue was used will play a part in deciding how to proceed.

Thanks! I will look in there this evening and try to get a pic. I seem to remember seeing what looked like some orange/brownish glue up in there near the block

I know that there has been several repair around where the tailpiece attaches and the binding is not lined up well on one side of the back do to a likely removal.

[Ky Slim]

A few more pics. This thing is in pretty rough shape but I'm still thinking it could be worth some frets. And tuners. and glue...
Anyway, I'd prefer the option that does not involve removing the back but I don't want to have to glue now and then again, and again if that spot might continue to open up. So if it needs to come off it maybe I'll take it to someone with greater skills than mine. It sounds pretty good and actually holds tune.


I think that it looks pretty clean in the opening where it is coming unglued. Perhaps I can just glue and clamp.



The back was definitely removed and replaced before. See these circular clamp marks.



The binding must not have lined back up during the previous repairs or one of the previous repairs and they filled the space with something. The binding is smooth in places and rough in places.



There is some glue next to the block. I'm not sure what kind it is. It looks like elmers to me...?

[Frank Ford]

Removing and regluing the back would be the best way to go, but realigning it in the process isn't for the faint of heart. I drag out all manner of clamps and use just about every trick I can muster when I go at these sometimes:



Here's more on that subject:http://www.frets.com/FretsPages/Luth...nchclamps.html

Also, if you're a Facebooker, you might dig through the stuff recently posted by Gryphon Stringed Instruments, which features some shots of me doing this same job on a similar vintage A-1.

[Ky Slim]

Wow Frank! You certainly pull out all the stops on those projects. Very impressive Sir!

This A2 that I have could certainly use that kind of magic but I'm afraid that kind of repair may be a little costly (maybe even cost more than I paid for this A2). So I'm leaning toward some hide glue, clamps and crossed fingers.

I think it would be helpful to know how much of the arched back sits directly on the neck block. In other words, can I shoot some glue on the block and then clap a couple times back from the heel? How far back -away from the heel - is there glue-able contact?

[Bill Snyder]

The inside is not carved over the block.

[Ky Slim]

The inside is not carved over the block.

Ok. So is it normally flush with the block and glued to it?? Or is glue normally just placed around the outside.

[Michael Lewis]

Poke about in the separation to see if you can determine what kind of glue was used on the surfaces of the back and neck block where they make contact. That bit of glue blob on the inside is sort of indication that other than hide glue was put there, and must be cleaned off. Hopefully it is all hide glue. (hide glue becomes slick and sticky when water is put on it, Titebond or Elmer's not so much, and they become milky).

You can try just adding glue and clamping but you already know it not likely to be a good repair, but it MIGHT work.