Pearl Fingerboard Bruno Mandolin

[Chris Vallillo]

I recently purchased this turn of the century Bruno Bowlback mandolin with a pearl fingerboard.  As you can see, it's missing several sections of pearl which I intend to replace (including the abalone inlaid in pearl section which I'll have done by a pro) but the real issue will be a neck re-set.  To remove the neck, I'll have to either remove the fingerboard or loosen the fingerboard extension, both of which I have done many times, but not with a pearl fingerboard.  

What little I've found online about pearl fingerboards suggested that the pearl will pop off easily and could be damaged with out much effort and the 4 missing sections correspond with the area of the neck that has bowed the most supporting that idea.  In addition, the fingerboard under the pearl seems to be quite thin.  I'm concerned that normal techniques like heating and prying could do serious damage.  

If anyone out there has any experience with this, I'd appreciate their thoughts on how best to proceed or where I can look to find that info out. I've tried searching this forum and Mandolin Cafe with no luck.

Thanks very much.

[Paul Breen]

Chris, the bar you see in the picture that I am clamping is a short length of plastic, cut nice and straight. It only comes in contact with the carbon rod and it's Ebony cap.

Running the router directly on the neck will let the bit follow the curved contour of the neck warp. The smaller the router base, the better.

Here is a picture of the double stick tape I like, the one on the left with the tight weave. The other stuff is Scotch brand, not so good. I don't remember what brand the good stuff is and it's not marked on the roll...I'm almost out too.

[Chris Vallillo]

Ah, yes, that all makes sense.  I'll probably need to get a smaller router (unless a good Dremel with a router set up could do the job).  I'll look around and see what type of double stick tape is available.  

[Chris Vallillo]

The new fingerboard arrived from LMI today.  I ordered a custom slotted rosewood fingerboard based off of measurements of the original fingerboard.  I didn't match the fingerboards up perfectly while shooting this pic, but it's a perfect match.  Actually, it's very beautiful rosewood... kinda sorry to cover it up!  The second, ebony fingerboard is for a Pear shaped Mandello I'm also restoring.  

I'll pull off the old fingerboard tonight and post shots.  I fully expect it to disintegrate, but at least I'll be able to see what's beneath it.

[Chris Vallillo]

Here's the latest,  I pulled the disintegrating fingerboard, and as I feared, it just fell apart.  I was able to save the profile of the curved end to use as a template for the new one, but that was about all.

When I finally got it off (removal was complicated by a previous attempt to glue it together), I could see that it appears to be a butt joint.  

The actual neck itself doesn't appear to be too bowed... but clearly the neck set is off now.  It could be that the neck block or butt joint moved over time or when the instrument got hot.  I'll have to ponder just what needs to move before I go much farther.  

[Roger Häggström]

Looks much like a "Spanish heel" to me. The neck and neck block is the same wood. Either that or a flat surface between the neck and the neck block and the sides mounted into grooves in he neck. Never seen this before.

[Paul Breen]

Appears you're neck attachment is likely the same as the Neapolitan picture I posted with the top off, an integral neck block. You could verify this by removing a small patch of Spruce top over the joint area. It can be glued back on later and will eventually be covered by the finger board.  

If it is an integral neck block, I would suggest making a Mahogany shim, the entire length and width of the finger board footprint to correct the neck angle. This assumes that the neck to body joint is still rigid.

[Chris Vallillo]

That sounds like a solid way to go.  I had considered removing the split section, but was concerned about messing with the intact inlay around the sound hole.  I can simply cut across the grain at a point that will be covered by the fingerboard when it's completed.  I had planned on re-enforcing that area anyway.

I took a look at the earlier pics you posted (Thanks very much for that, it's a great help!).  Does the heel block have a "shelf" cut into it where the top attaches?

At any rate, I'll remove a small section later today and post pics tonight of the joint.

[Chris Vallillo]

Here's the latest:  I pulled a section of the top off to reveal the neck juncture and yes indeed, it is a single block as had been suggested by Paul and Roger

Armed with that information, I can surmise that this instrument probably got hot and the glue joint around the neck block slipped.  There is a very small separation on the bass side of the neck junction that might indicate this.

Here are a few more of the shots of the neck joint:

In addition, I can see evidence of someone having done a "dump and roll" glue job inside at the point where the ribs connect to the heel block complicating things a bit more.  

Time for more thought on how to deal with all this.  If the neck block glue joint is solid with the ribs and not likely to move again, I may be able to make adjustments to the neck and fingerboard to make things work.  If not, I may be looking at pulling the top (not my first choice, but a possibility). 

[Chris Vallillo]

More news:  I did indeed pull the top, saving the original binding for re-use (I do this whenever I can and usually have great success).  Glad I did.  As I suspected, the braces were loose on the ends and the cracks in the top and back are much more easily dealt with this way.

Though it was fairly stubborn and needed quite a bit of heat, the top came off clean with almost no tear out.  As you can see, there had been previous repairs to this.  I'm on the fence as to whether or not the top had been taken off before.  I didn't see any indications in the outer finish, but the previous repairs and the nature of the glue joint suggested maybe it had.  All three braces had one or both ends loose plus a major break near the fingerboard as well as 2 other splits in the top.   There are a couple minor splits in the bowel that will also be much easier to deal with now.

Here's the glue joint on the neck block... clearly a repair which supports the theory that the block slipped slightly allowing the neck to pull forward.  At this point, I'm not entirely sure that I can disassemble that section and re-do it without making things worse.  I'm going to consider other ways to straighten the neck first.  

Opinions of more experienced luthiers would be greatly appreciated at this point!

[Chris Vallillo]

A lot has happened since I posted last (including a full make over of my workshop). I have received the custom slotted fretboards from LMI, but am dealing with other issues first.   I did glue the loose braces and several cracks in the top.  

I also repaired several back splits as well as re-did several earlier repairs, re-alighning and re-glueing several of the back sections (the light blue cloth is my repair, the tan cloth, previous repairs). 

After working on the back, it was apparent that things had come loose at the butt end fairly significantly and to a smaller degree at the neck.  Once everything was stabilized, I heated the neck joint with a hair drier, then gently applied pressure to the neck and joint area to see if I could move things back.  

Things did shift a bit, but nowhere near what it will need for a proper neck set.  Rather than attempt to remove and re-set the neck (since the neck and neck block are one solid piece) I've decided to try to a combination of that bit of heat bend I did, with shaving the back section of the neck and thinning the head end of the fingerboard (already significantly thicker than the original)  to come up with the proper neck angle.  A bit at each point could add up to what I need need.    I'll re-attach the top before I start to work out the amounts of material to remove.

[Chris Vallillo]

I got the top glued on a couple days ago.  Tight bond since I needed the extra setting time to put everything put together.  Rubber band strips to clamp it up.  It came together surprisingly well.

After cleaning off the squeeze out, I re-used the original binding.  I know lots of folks don't bother with this, but I do if I can, and it adds an extra layer of authenticity to a restoration... if it works!

The final results proved good.  I needed a bit of scraping to level the binding in a few places, but the mandolin will get a light french polish re-finish so no problems finish wise.  

After I re-glued the top, I decided to add a couple "popsicle" braces around the sound hole to remove a bit of warp and add strength the neck joint area.  

I've tried fitting on the thicker fingerboard blank and think I'll be able compensate for any neck issues  with a bit of judicious sanding on the high end of the neck and fingerboard.  It will also add significant strength to the neck and should help avoid the problems this had before.  I've talked with the pearl inlay specialist I'm using and the missing pearl sections should be done and here soon.  More to come.