Gibson a jr open seam on back.

[LongBlackVeil]

My A Jr has an open seam on the back about a couple of inches long wide enough that you can see light coming through. How urgent is it that I fix this? Is it a pretty easy fix? And finally, could I trust a good violin shop to fix it? No mandolin repair people close by but there are some well respected violin shops.

The open seam starts from the neck block and runs all the way down to the top of the label

[Rick Lindstrom]

Not an exactly "easy" fix, and also fairly crucial to get it repaired before it gets worse. Probably a good idea to let down the string tension now and wait for advice from others on this forum about who to take it to.

[LongBlackVeil]

Thank you. From what I understand it's one of the more common repairs for a violin, and the violin forums made it seem like no big deal to fix. Not sure if it's any different here or not.

I would think as long as the back doesn't have to be removed it wouldn't be too difficult, but what do I know

[sunburst]

From what I understand it's one of the more common repairs for a violin, and the violin forums made it seem like no big deal to fix. Not sure if it's any different here or not.

It's different.
Violins have very small head blocks and the backs are glued on with a relatively weak glue mix. Your A jr has a huge head block and the back is glued to it like they never intended for it to be taken apart (they didn't).
A violin repair person might release the back from the block to fix the center seam of a violin (depending on the situation, the person, the instrument, etc.), repair the seam and re-glue the back to the block. That is not as feasible with the mandolin.

Another reason that it is easier to release violin plates from the rim is the overhanging plate edges. Not only does that make it easier to get a tool to enter the joint, but it means realignment is easier when re-gluing the plate to the rim.

Hopefully, the open seam on your mandolin can be closed with proper humidity, and re-glued without the need to release the back from the block, because that can be very difficult on old Gibsons.

[LongBlackVeil]

It's different.
Violins have very small head blocks and the backs are glued on with a relatively weak glue mix. Your A jr has a huge head block and the back is glued to it like they never intended for it to be taken apart (they didn't).
A violin repair person might release the back from the block to fix the center seam of a violin (depending on the situation, the person, the instrument, etc.), repair the seam and re-glue the back to the block. That is not as feasible with the mandolin.

Another reason that it is easier to release violin plates from the rim is the overhanging plate edges. Not only does that make it easier to get a tool to enter the joint, but it means realignment is easier when re-gluing the plate to the rim.

Hopefully, the open seam on your mandolin can be closed with proper humidity, and re-glued without the need to release the back from the block, because that can be very difficult on old Gibsons.

I was hoping you would chime in here. Thanks, that makes it pretty clear.

So lets assume that it could not be fixed without removing the back. Would the best option be to just leave it be? It does sound good, as good as other A Jrs ive played, maybe a bit weaker in the trebles but not so much that its much difference from the natural differences between any other two isntruments

[LongBlackVeil]

Just to make clear what we're talking about here's a picture. It's been that way for awhile now

[sunburst]

That actually looks pretty sound where it is glued to the head block, some humidity and some manipulation might close that one up and a good repair may be relatively easy.

[Wes Brandt]

These days, though I don't do much repair now, I would take this instrument and put it in a box or bag or something so you can bring the humidity up to 80 percent or so (use an accurate gauge) and leave it for a few weeks… then crack open the container and slowly let it return to 40 or 50 % over a couple weeks. Then see what you've got.

If it was really dried out at one time and never exposed to higher humidity this might close it up… even at normal humidity. Wood that has been very dry will sometimes shrink and not return to it's former dimensions until it is exposed to the opposite extreme… just 50-60 % wont do it. This doesn't always work but if you have the time it's the best way to try…

Otherwise, myself I wouldn't take it apart for this separation… it's so minor… I would try to get in as much splinting as I could and fully cleat the inside or even add a thin spruce strip like the backs of guitars get. Fill what you can't splint with putty made from very fine wood dust and thick hide glue… then touchup or at least satain and seal it

The forces on this crack are not that great or dangerous so it's almost a cosmetic problem.

[pops1]

I would try to plane some thin shavings that fit snugly into the crack and glue with HHG. I have done this before and it works well. It can be colored dark easily, but it won't be invisible.

[LongBlackVeil]

So, no emergency here?

I don't need to be in a rush to have it fixed?

[UncleNorm]

It's an open separation, so the longer you wait to do a fix, the more likely dirt and oils from your hands etc. will get in and make gluing later more difficult.

[Jude Reinhardt]

You might cover it with blue painters tape to keep stuff out until you decide on a fix.

Jude

[LongBlackVeil]

You might cover it with blue painters tape to keep stuff out until you decide on a fix.

Jude

Hmm, maybe I should just duct tape it and call it a day :P

[sunburst]

Don't tape it. It will do no good.
Duct tape is quite the fashion statement, though.

[liestman]

Not sure what part of Texas you are in but I would suggest you get it to Dave Trexler at Fiddlers Green in Austin. He does excellent honest work.