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 Post subject: Help for this tater bug?
PostPosted: Sat Jul 26, 2008 9:50 am 
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Brazilian Rosewood
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Location: Newark, DE
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At a recent gathering of friends, one couple, who had been cleaning out the old family home, produced an old round back mandolin that had been there for who knows how long ( the couple are my age, mid 50's, and the woman, the family daughter, had never seen the mandolin prior to finding it). They gave it to another friend who is an accomplished and previously very active mandolinist. He, in turn, took one look at the sunken top and handed it to the resident proto-luthier -- "maybe Kirby can fix it?"

Some additional info before pictures. There are no identifying marks on this that I can find. I'm assuming that it has no particular value, and that there is no economic justification for pursuing a fix at the level which will probably be needed. There is no particular sentimental value to the instrument. Main question - do you think it is worth pursuing as a learning experience for me? and is the obvious path a retop, or can the amount of sinking that will be shown be fixed?

Here, first, are general shots. Note that the original binding appears to be intact along one side, but that something drastic has been done on the other side at some point. (Looks like body filler putty, so I'm assuming the mandolin partially came apart at some point and was put back together by someone with no knowledge of what they were doing.) There has also been at least a partial refret job, and it is horrendous - lots of fret tangs at wild angles, etc.

Attachment:
P1010123.JPG


Attachment:
p1010122.jpg


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p1010124.jpg


Attachment:
P1010125.JPG


Now for the bad part. The top is pretty caved in between the neck and the bend in the top. The first top picture shows a line across the top at the bend. There is about a 1.5mm sink here. The bridge, just in front of the bend, has been sitting on this depression so long that it has relaxed into the dip and retains that shape when it was removed. (The mandolin was still strung up).

Attachment:
P1010121.JPG


The next two shots show lines across the top at the bridge side of the soundhole, and along the top from the neck end to the bend. The dip at the soundhole is 6mm.

Attachment:
P1010120.JPG


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P1010127.JPG


Finally, a shot of a separation in the top that continues back under the inlay but not to the top bend.

Attachment:
P1010128.JPG


I don't know what the internal brace layout usually looks like for these. This one does not have a brace under the bridge, or anywhere in between the soundhole and the bend in the top.

So what would you do? Again, I assume the instrument is not worth the hours that would be involved, so the value is educational.
Thanks for looking.


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PostPosted: Sat Jul 26, 2008 10:13 am 
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Location: Spokane, Washington
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Seems it would need a new top as a minimum. These things commonly need neck resets too. This one probably does from how the top has sunk between the bridge and the neck. I seldom see one that doesn't need a neck reset.

There isn't a neck joint per se, just the block where the back joins, so that would require resetting the block. It's probably not worth more than a few hundred even in good condition since it appears to be a low-end one, so yes, this would be learning experience, if you think it's worth the effort.

But if the action is acceptable, I'd fix the top crack and do a refret. One thing I have seen done with these is a thicker fretboard to help with the action. But once the neck has started to move, there's no stopping it, so the thick fretboard trick might not be a good long-term solution.

Pat

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PostPosted: Sun Jul 27, 2008 12:58 pm 
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Brazilian Rosewood
Brazilian Rosewood

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Thanks, Pat.

So, you have to loosen the whole neck block? This sounds harder than than slipping the foot on a classical guitar!

I have the go ahead from all involved to go at it - so I'll ponder this and decide where to go.

I'd be curious about how to lift the inset (tortoise?) and inlay off the existing top. Is it likely that this was put together with hide glue?

Jim

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PostPosted: Sun Jul 27, 2008 1:00 pm 
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Brazilian Rosewood
Brazilian Rosewood

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Location: Newark, DE
First name: Jim
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ps: If anyone has a picture of the inside of a top from one of these, I'd be glad to see it. I have a suspicion that this thing shed a ladder brace below the sound hole sometime in the distant past.

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PostPosted: Mon Jul 28, 2008 10:16 am 
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Brazilian Rosewood
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Kirby, here is one I worked on in 04. It had a broken loose and broken top brace. They are ladder style if I remember right. Probably the hardest thing I ever worked on. Good luck.

If all else fails send it to Frank Ford..... he can fix anything. But I bet you can handle it!

http://dickeyguitars.com/dickeyguitars/JDTtaterbug.html

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PostPosted: Mon Jul 28, 2008 11:25 am 
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jtkirby wrote:
Thanks, Pat.

So, you have to loosen the whole neck block? This sounds harder than than slipping the foot on a classical guitar!

I have the go ahead from all involved to go at it - so I'll ponder this and decide where to go.

I'd be curious about how to lift the inset (tortoise?) and inlay off the existing top. Is it likely that this was put together with hide glue?

Jim


Yes, it would be a lot harder than slipping a foot. All the ribs of the back are glued to it, and at that joint is where the angle is set.

The ones I've seen of this era used hide glue. Judicious application of heat should do it. The pickguard inlay, being old cellulose, will be extremely brittle and very easy to break. But if the crack stops somewhere under the inlay, I'd put in a cross-grain overlay under the crack, sort of like a bridge plate, then splint the crack where it shows. This wouldn't be a "proper" repair, but I think it's appropriate given the value of the instrument.

Good luck!

Pat

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PostPosted: Fri Aug 01, 2008 11:35 am 
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Walnut
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Kinda late reply, but if all else fails that inlay would work great for making a SRV Lenny stratocaster copy.

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PostPosted: Fri Aug 01, 2008 12:05 pm 
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Old Growth Brazilian
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Ship it to Colin :D this would be right up his ally


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