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.

[LARRY KLOSE]

Besides the staining factor, some cheap palette knives are chrome plated steel and applying significant flex or pressure will tend to crack the plating, making the knife pretty much useless.  I second the stainless recommendation.

Larry

[Chris Vallillo]

Here's the latest news:  I tried heating the fingerboard extension with a light bulb to ease it's removal but the fingerboard material is just crumbling.  I've seen this in dyed pear wood fingerboards before and there is no way to prevent it.  I've decided to stop before I destroy it to the point where I can't use it as a template for the new one and go ahead an re-create the underlying section before I remove the original.

The original wood is only .09" thick and routed back for binding on the edges so I don't think it adds much in the way of stability to the neck joint.  I've got scrap pieces of Indian rosewood, ebony and ziracote that I can use to re-create this.   I'm leaning towards the rosewood because it's almost a perfect match thickness wise already but I'd appreciate anyones thoughts on what might add the greatest strength.

[Roger Häggström]

That's the thing with restorations, you have a plan and when you start doing it for real you have to change it. That's one thing I love with this work, always new problems and a new smart solution to figure out!

You can never go wrong with rosewood in a fretboard. Keep track of what you take off (pictures are great!) and re-create later, it is always possible.

I have had a couple of ebonised fretboards in US made parlors and they could not be saved. I replaced them with ebony.

[Paul Breen]

If you're worried about strength, you could rout and epoxy in a carbon fiber rod into the neck. A thin finger board, once it's cut for fret slots won't contribute much strength. I wouldn't worry too much about the wood species since it will all be covered but I would use something hard that works well and won't splinter much when worked.

[Chris Vallillo]

Thanks for the additional  shots, Paul... the journery begins, indeed!  Rather than try to recreate the fingerboard myself,  I've ordered a replacement fretboard with pre-cut fret slots from LMI (a $9.00 fee, much cheaper than me trying to cut slots myself.) made to match the original scale and will post shots when it arrives.  Until then, since the original fretboard is in such deteriorated shape, I won't remove it from the mandolin (It will surely disintegrate).  I'll compare the new to the original while it is still in place to make certain they match.  Once I deal with that, then I'll tear into the neck issue.

[George Roberts]

Bruno was a musical instrument dealer rather than a maker, and there's probably no way to tell who made your mandolin.  I worked on a Bruno guitar of that approximate time period, and the neck joint was a simple mortise and tenon.  The tenon was a 1/4 inch extension of the heel, and the mortise was 1/4 inch cavity into the neck block.  I posted a picture of the joint on the "Neck Reset Gallery."

[Chris Vallillo]

I've heard that.  An excellent repair man in Wisconsin told me he thought many of their parlor guitars were European made.  I do recall some early Bruno's were Martin made but I believe that's well before this mando.  Regardless, they are generally well made instruments constructed of excellent woods with fine craftsmanship.

I'm nearly finished with a Bruno Parlor from the turn of the century.  Brazilian Rosewood back and sides, Spruce top, ladder braced, rosewood fingerboard.  It has a butt joint for the neck joint and a very tiny heel so I'm planning on trying high gram weight hide glue to put it back together.  Several folks suggested converting it to a bolt on, but the heel is so tiny, I don't believe it could take the strain.  I may have put that one in the Neck Reset Gallery as well. I'll check out yours!

I'll take pics and post them as I move forward.  I'm new to bowlbacks so this will be a learning experience for me. 

[Chris Vallillo]

Roger, Yes, I agree.  The thing I love about restoration is that it's essentially problem solving in 3D.  I made a fingerboard blank out of the rosewood, but I am considering the ziracote only because it's a bit thicker which could add a little more strength.  

I been thinking about your idea, Paul. I'm very concerned about fingerboard strength.  I think the unusually light fingerboard lead to the neck issue so I want to support the neck junction as much as I can.  The current fingerboard (without the pearl) is only .09" thick.  Clearly not much strength, particularly with the deteriorated pearwood.   I've never put in a carbon fibre or truss rod yet, but most of the vintage instruments I deal with have warped necks so I imagine it's a skill I need to learn.  

After I deal with the fretboard issue, I'll take a look at the inside construction.  The neck bend is so great and specifically at the neck/body junction that I suspect the neck block has either failed or slipped.  If it's just a matter of repositioning the neck block, I may be OK, but if I need to correct that much bow, I'll be researching carbon rod installation!

[Roger Häggström]

I put a carbon rod in almost all the the old parlor guitars I'm restoring. I can't see a good reason not to do that with the fretboard off, it's invisible and don't add weight. My experience is that it's good for the tone too, a neck is at it's best when it's stiff, but not too stiff. Makes the neck predictable and stiff enough in the long run for light steel strings.

I would consider a hollow square tube of the right size for the mandolin with a birch wood bar in the hole, made a post about that recently.

[Paul Breen]

If the neck is just bowed/ warped, a carbon fiber rod can go a long way to straightening it. If the neck angle is off on the other hand, there may be a big can of worms waiting for you. Here is a few pics of a teens, Gibson oval hole mando and the somewhat low tech method I use to rout a groove in the neck for carbon rod therapy.

This mandolin had a rather badly warped neck. Sanding the finger board flat could have flattened the playing surface but would have removed most of the finger board at either end, I didn't want to do that. The strategy would be to remove the frets and finger board, rout a groove for the carbon rod that follows the warp of the neck, epoxy the rod in place and clamp it all with a straight caul. This uses the strength of the rod to pull the neck back as flat as possible. My preference for this is a solid rectangular shaped rod with the tall dimension let in vertically to a narrow groove that is deeper than wide. Once the epoxy has set, I do some minimal sanding to further flatten the neck before the finger board goes back on. Once the finger board is back on it will get a final flattening before fretting which is then leveled, re-crowned and polished. This process lets you flatten things incrementally at each step, most of it being accomplished when installing the carbon rod. This worked very well with the old Gibson, I hardly needed to sand anything off of the finger board.

The router set up is rather casual but works if you don't push hard against the template and do several passes to achieve the target depth. I use a high quality double stick carpet tape along the entire length of the neck and a 1/4" thick template for the router's template guide to follow. The tape is a thin fabric with thin sticky on both sides that looks like a loose woven linen. They make stuff now that looks like double stick gauze that doesn't work as well, be picky with quality of tape.

You're going to need some way to hold you're bowl back mando, a pattern vise works very well for a way to secure a mandolin for routing. 

Obviously, a small router is desirable and you may need to grind the router's template guide shorter to run on 1/4" thick stock. The router bit is already the correct width for the rod, so the template board doesn't get moved once it's set.

Finished groove, carbon rod and wood cap ready to go. The wood cap can be any wood species, I used a scrap of Ebony.

Epoxy in the rod and cap at the same time. Use a clamping caul that is the same width or slightly narrower than the rod and clamp it tight. This is where most of the warp will be flattened.

Note the Maple stiffener used by Gibson in this Mahogany neck. I'm pretty sure this was just done in the teens years. It is a "V" shaped profile and it extends up into the headstock.

Do some sanding after the clamps come off but don't be too aggressive. The more you remove at this point the skinnier the neck will get! On this Gibson, where the neck extension glues to the body it would get wider. 

Before I removed the finger board, I drilled some small holes through a fret slot at either end to use as alignment pins when it goes back together.

[Chris Vallillo]

Thanks VERY much for this excellent post.  I'll definitely be giving this a try soon! 

In the 3rd picture it looks like you are clamping a solid metal bar on top of the rod and wood cap.  Do I correctly assume that this is the caul you spoke of that will do most of the flattening action?  Very ingenious.  My natural thought would have been to lay it flat across the width of the neck and clamp the whole thing.  

By the way, very nice old Gibson!

[Roger Häggström]

Nice work! The only thing I like to add is the possibility to use heat to bend the neck with the fretboard off straighter if it's really warped before gluing the carbon rod.