2017
Subject-Laminated necks
Topic -Glue Release-neck bow/warp
Hide Glue

Example:
1920's Slingerland Maybell tenor
Mahogany with Pear wood laminates
Conversion to 5 string for Mark Rubin


Since I will not be re-using this tenor neck I decided to make an example of it.
People that do heat pressing, and have heat presses done need to view it.
Animal hide glue was used because it was cheap and things could be taken back apart with heat or fluids to loosen the glue.
Over time, even in the best of conditions it can have release, and it is in areas that cannot be seen.
Also, the degradation of some woods used as laminates and fingerboards, overlays
(Pear wood in this example)
You can have the wood itself going bad, turning to powder , dried out and things just start letting go.
Heat is BAD, over 110F, and you will have "Creep" if glue softens for whatever reason.
Then you have 80 yrs or so of  HOT/COLD expansions and it all factors in to the end result.
And another big factor is finish that has worn away, sweat going into the laminates and releasing the glues from moisture and acids.
Many have seen sweat stains even on harder wood than Mahogany
This particular neck was a good choice, it was coming apart everywhere.

Note:
There are several views on why they used laminated necks.
Most views say "Well it added strength and a nice look"
Some say "Ply's are always stronger than solid wood"
I will allow those arguments, but I have my own as well.
My opinion was that you could use much smaller pieces of wood.
Solid necks took a complete billet, while laminated necks could be done with 1"x 3" boards and 2 -1" pieces of ear wood.
So the more lamination's, the smaller the main wood, hence, using up what could be considered scrap.
It was a "Waste not want not" world then.

The de-lamination will be shown on down the page, this is also an on-going project for Mark.


First, I slipped the overlay from it to mount onto this replacement neck.
Notice how far off center the inlay is.
That is because production banjos are were held to a much lower standard.
Now , you cannot get away with that as a custom builder :):)
The bottom holes match up OK, will plug two and drill two new ones.


Glued and shaped, will add extension.
Still off center, by default :)




Wiped up, will go on with Renaissance.



TENOR NECK EXAMPLE


Once overlay's are off, its visible how things are inside.


I will be using the inlay for the new neck
The Pear wood Fboard is not too degraded on this one
The center laminate, you can already see, is dry
The glue on the fingerboard surface area allows it to stay together for so many years.


Barely tapping it, its hardly stuck

Good...thick MOP.

Dry all the way up the course.



Then I took a razor knife and just slice right down one side of the laminate.



Dowel is still nice and tight, that is Maple to Maple joinery.
See the blade separating the center Pear wood laminate.
It is all soft and splintery down here.
The main point to notice is that it's falling apart with little effort by me.





You can see a little that is still real tight to the neck side in this pic.
That is where you see more long shavings.
The rest was loose


If you can see the crosshatching marks on the neck, you will see what Luthier's still practice to achieve a Glue bond with the wood.
Roughing up hardwoods is always a benefit.









Time to get the inlay in



3/8 Forstner is the exact tool, no filler will be needed.
These are plastic dots so easy to drill through.




It already has side markers.
All glued in, truss cover made, ready to install Slingerland dowel.

SCOOP
Sometimes I just do what I want to.
Mark has been a fine Amigo, and has helped me many times so I want to do  a little more than just convert this thing.


Pulled frets to the last marked fret, sawed it down, and pulling it off




Since Slingerland is known for using green laminates, I am using the absolute last pieces of the Dale Small estate veneer on this one.



It already had a crack but I hd zero room so it haspatina from the get go.
After sealing and shaping.


I need to reduce the back of peg head to get on the back strap
Sure Form makes quick work of it.


Roughed in with a seal coat.
Very Slingerlandish


Same for heel cap


Coat of sealer, ready to tint to match rim


Then it will just be clear coats



First thing, neck notch needs to be cut deeper, the Slingerland style hoop rides down, and that pushes the neck down, below the plane of the head.







Dowel tenon drilled, dowel fitted, ready for glue.




Now I have plenty clearance.
The neck is riding high with good neck angle.
 I will lower this now by dropping the bottom from the rim mortise.


All fitted, ready to tint for closest match possible to the original yellowed varnish on the rim

BUT FIRST...
Anyone that knows me knows that crack in the side of the green would wear me down so I made an alteration.
2 mahogany sectionals.




Now tyo drop the bottom down, this will bring my neck right where I need it.
I can have a high bridge, plenty of down force for the build and still a nice low action on the neck and over the scoop.


Put an ID on inside of truss cover.

FInal assembly


Color suits me now


I will steel wool it all to satin, then hand buff it, to make it look right for the rim.




5 star tuners and a friction fifth. Ivoroid buttons


Do not like the plastic pip, its outta there.


Last of my good bone pips, CNC'ed at 1/8"

SETUP


Sullivan Old Growth Bridge, 19/32.
No knot Tailpiece
11-21-15-13-11  La Bella Strings


I will wait a couple days to tune it to pitch, let the dowel setup nicely.
I feel good, the build went well and hace a nice Maybell appeal to it.



If a man wanted to run a high crown head now, I think you could get the tension hoop flat with the rim and with that smooth top hoop, negate the need for an armrest.
Maybe on the next head change if it Mark keeps it around.



















Thanks for watching,
Vinnie