Question about Gibson L-OO top bracing

[John Cartwright]

Hi folks, I'm repairing an early 30's Gibson L-OO (someone installed a mile-high saddle that caused the bridge to crack, so I'm replacing that - no issues there though) but I found a small bracing or possible repair patch in the case.  The guy isn't sure what it went to, he's having this guitar repaired for his brother.  It has a beveled cut-out for the sound hole and fits pretty good, but does not fit exactly (see picture)  I can't find any pictures of original bracings for this guitar, so I thought I'd ask you guys since you have been enormously helpful to me in the past :-)   The last picture shows me holding the mystery piece against the top with my finger.  

 

Is this original? Its patina indicates some age, but how much age I don't know.  there is a hairline crack between the upper shoulder of the guitar top and the last bracing before the sound hole, but nothing after that that I can see.  

 

Glue it in or leave it out?  Thoughts?

 

Many, many thanks!

John

[John Cartwright]

Looking at the photos now that they're loaded up, I'm seeing dried glue squeeze-out where there would be none had this piece been installed in this guitar, and the glue looks a little different in color too.   Perhaps seeing the photos has revealed the answer to my question, but perhaps not.  Feel free to chime in with your thoughts on the matter.  Thanks!

[Mark McLean]

Hi John

I am currently building my second L-00 guitar so I have spent a bit of time looking at a number of plans from different sources.  None of them show this type of soundhole brace.  So, I don't think it was glued there in the Gibson factory.  It looks like a repair (a pretty rough one) added later.  The poor fit and the glue residue would be consistent with a repair done through the soundhole without direct vision.  I bet the bevelled edge of the curved side was done with a knife after the piece was glued in. 

Why was it done, and should you replace it?  Well, the most obvious reason would be thet it was put there to reinforce under a repaired soundboard crack.  Any sign of that?  Your first photo seems to suggest a crack which disrupts the continuity of the rosette rings, slightly to the treble side of the midline.  If that is the case it might be a good idea to replace it.  But, on the other hand, it presumably fell out some time ago and the guitar seems to be getting by fine without it.

cheers

Mark

[John Cartwright]

Mark (or anyone who knows), I've been informed that the bridge I just removed had been a replacement of the original.  Before using this broken one as a basis for the new bridge, I ran a straight edge down from the outer nut slots to the center of the corresponding pin holes and all looked good.  However, I thought I would check in to see what the actual string spacing should be on this guitar - I've got 2  7/16" from center to center of the two E strings.  The holes are a tad crooked lengthwise (end of guitar to fingerboard, direction) but look well spaced width wise, between each.  I suppose I could fill with spruce plugs, replace the otherwise healthy bridge plate and re-drill. Or would using the sawdust and CA glue method be fine for this?  When I say the holes are a tad crooked, I'm talking 1/64" to 3/64" difference at the most.  They would like to keep cost low, so I'm leaning toward the the saw dust and CA glue method, but wanted to get your all's thoughts first.  Thanks!

[Mark McLean]

You would be doing a lot of work to realign the pin holes, for a very minor cosmetic issue.  Does it really look off when the pins are in the holes?  If you are going to do this you need a firm surface to drill new holes into and I don't think glued sawdust will be strong enough.  You would be best to use a hardwood plug. Alternatively, you could get slightly bigger pins and ream the holes in a manner to better align them?  Or, live with it as it is.  My 2c worth is don't do anything unless there is an actual structural problem with the bridge or the plate - or it really looks bad.     

Cheers, Mark

[John Cartwright]

Thanks Mark,  If you spend some time with it, you would notice it.  I'll go with the hardwood plugs and re-drill.  I hate the thought of making a brand new bridge only to put crooked holes in it.  Did the 2  7/16" string spread from E-E look to be factory correct to you?  That's the reading I got with the old bridge.

 

Again, thank you! 

[Paul Hostetter]

Hardwood plugs are not quite the answer. String balls pull on the bridgeplate, which does the work. That surface needs to be right. Usually you replace the plate or resurface it—without holes—and then fill the remaining holes in the spruce with spruce, not hardwood. In other words you restore each layer, then glue the bridge on and then redrill the holes.

 

Stew-Mac makes a nifty device for salvaging bridgeplates, but it's sufficiently expensive that you need to do this operation many times before you get payoff on that tool. But hardwood plugs are not called for. A good bridgeplate, however you arrive at it, is the ticket.

[John Cartwright]

Thanks Paul, The Bridge Saver looks nice indeed, but unless you're buying....  I'm still not officially up and running in a full fledged operation, and I mostly do work for friends right now.  I just don't have that kind of cash.  I'm fairly well equipped with the main stuff for the job, but a lot of these types of items are just out of reach right now. 

Do you suspect a major problem will develop with the use of hardwood dowel plugs here?  I intend to overlay a very thin maple veneer to the bridge plate as mentioned as an acceptable fix in one of Dan Erlewine's books.

 

[fred marcuson]

first pic shows a crack at the end of the fingerboard .

that patch was put there to keep the sound board level ....??

[Paul Hostetter]

Not original, and not even called for. The squeeze-out is aliphatic, but Gibson used heated hide glue—you can see what they each look like in your 3rd picture.

It's hard to tell from the second photo, but I'm wondering if it had ever really been in that guitar, or had been in some other guitar and was simply just lurking in the case. It looks awfully clean inside there now. It also evidences the kind of fit you get when you're doing everything through the soundhole, out of sight. If it was ever in that guitar, it would have probably been closer to the soundhole, as the beveling looks as though it was done after the patch was glued in, and that wouldn't have been possible if it was ever set that far back.

 

The tiny crack at the end of the fingerboard is collateral with the shrinking celluloid soundhole ring, not structurally threatening, not meriting a repair.

 

My two ¢.

[John Cartwright]

Thanks everyone!  A closer look at the suspected crack mentioned in pic 1 shows that Paul is correct, it is just lacquer checking.  Also what I thought was a hairline crack preceding the the bracing (not visible in any of these photos but mentioned above) is actually a slight discoloration to the wood that fades away before reaching the bracing.  So it's looking more and more like the patch had been just floating around in the case.  The case is much newer than the guitar, and he might have purchased the case used too - it's way too big for this guitar though, would fit a easily, but I digress.  Many thanks guys!