Gibson Guitar Repair : 1969 Southern Jumbo

The owner of this lovely old Gibson SJ thinks it doesn’t have the sound projection that it should have.

My suggestion is to fit a GPL Saddle Insert to replace the existing adjustable bridge saddle.

Adjustable bridge saddles of this type were used by Gibson and Epiphone on their acoustic guitars during the 1960s. This adjustment gives the player the opportunity to set the action to the required height to suit the player’s style. However, when the saddle is set to a good playing action the saddle makes no contact with the soundboard; this is the down side to this system. This lack of contact is due to the saddle being suspended on two adjusting posts. These posts are screwed into two threaded inserts that are housed into the soundboard. Therefore the transmission of sound vibration from the strings to the soundboard is via two metal adjusting posts. This is not an ideal situation for producing good volume or tone. Simple logic would dictate that the more contact the saddle has with the bridge or soundboard the more transmission of sound, therefore producing more volume and more tone.

View Forum discussion here...

What is a GPL Saddle Insert ? A GPL Saddle Insert replaces the existing adjustable bridge saddle found on vintage Gibson and Epiphone guitars. It’s a non-invasive modification and can be removed if necessary. It’s an idea that I’ve used on several vintage guitars in the past which has enhanced the volume and tone and brought out the true voice of the guitar.

The Process

  1. The adjustable saddle is removed
  2. A GPL Saddle Insert is custom-made from matching woods to fit the slot
  3. The insert is glued into place
  4. The saddle position is marked out
  5. A saddle slot is routed into the insert
  6. A bone saddle is custom-made
  7. The string height is set for optimum playability

The GPL Saddle Insert is glued into place using high quality Hide glue. The remarkable thing about Hide glue is that it’s reversible. With most synthetic glues when it’s stuck it stays stuck. Not the case with Hide glue because it’s an organic material that softens with heat and moisture.  Therefore, by using a little heat and moisture the insert can be released and removed. Consequently, if the old saddle system needs to be put back into place it’s a simple job to reverse the above process and re-install the adjustable bridge saddle.

The Dilemma

Meanwhile the debate still rages on about the rights and wrongs of upgrading any aspects of a “vintage” guitar. Many owners of instruments that are of a certain age are reluctant to change any element of that instrument because it would no longer be origin. In a nutshell, if you have a guitar that’s 30 plus years old, making upgrades or changes to it could make it worth less than if it remained unchanged.

View a recent poll discussing the pros and cons of vintage guitar upgrades here…

The GPL Saddle Insert cuts across this issue because it is a non-invasive change that can be removed when required. If you have an old vintage acoustic that’s not living up to its potential contact this workshop and ask about the GPL Saddle Insert.

Update 23.01.11

An email from the SJ owner, shortly after collecting from the workshop

…………………………… it doesn’t show a lot of play wear and this might have been because it didn’t respond well and as a result, it never got the play for it to break-in and open-up since there was no vibration getting to the soundboard.   Now that the vibration is connected to the soundboard for the first time in its life, it might open up and get much better than it has ever been; wishful thinking or rational reasoning?  Even playing it last night warmed it up and as the evening wore on it seemed to sound better. I do have to say that it now does have a mystical kind of sound that is quite beguiling when one becomes familiar with it. As you can see, my enthusiasm has returned for the old SJ.

Vintage Acoustic Guitar Restoration:1977 Gibson Hummingbird

Here’s another golden oldie on the workbench, a Gibson Hummingbird made in 1977.

Introduced in 1960, the Hummingbird was Gibson’s second-most expensive acoustic guitar.

This guitar is interesting from a luthiery point of view as it has a Double X Brace system which was introduced on this model in 1971. In this system, two overlapping X shapes form a diamond which surrounds the bridge plate. Some manufacturers prefer this system where additional strength is required.

Here’s a mirror image of the Double X Brace system inside this Hummingbird

For reference purposes here’s a photo of a double X brace system that I built a few years ago.

This vintage beauty is in the workshop for a set up. It becomes clear during a workbench examination that this ol’ Hummer has some problems that will need to be addressed before it will set up to its optimum playability.

It has a very high action with a very low saddle height,  no room for adjustment there.

Its bridge is beginning to lift

On investigating the guitar’s action it becomes clear that the string height cannot be lowered at the bridge saddle and the only repair solution will be a neck reset. The bridge will need to be removed and re-fitted.

The Neck Removal and Reset

The 15th fret is removed

The fingerboard extension is heated and loosened

A hole is drilled through the vacant fret slot into the dove-tail cavity

The lacquer is scored around the heel

The neck is fitted into a Neck Removal Jig. Steam is pumped into the join to soften the glue

The neck becomes loose and is separated from the body

This date stamp authenticates the guitar’s age

The neck angle is adjusted using the neck reset formula and re-fitted

The Bridge Re-fit

The bridge is heated and removed

Herein lies a problem; this bridge (for some unknown reason) has been inlayed into the soundboard. This could be a reason as to why the bridge has begun to lift and will need to be remedied before the bridge can be refitted.

Take a closer look at the internal image; the bridge-pin holes (through the soundboard and into the bridge-plate) have become distorted. This could cause a problem when trying to re-stringing the guitar as the bridge-pins will not seat correctly.

The solution is to inlay a soundboard patch to restore the soundboard height and to repair the distorted pin holes

The Soundboard Repair

The area under the bridge is levelled and cleaned up

The pin holes are drilled out and fitted with new Spruce

The scratchplate is removed for ease of working

A soundboard patch is made up from Sitka Spruce,  glued into place and trimmed to thickness

The underneath of the bridge and soundboard patch are gently heated to extend the open time of the Hide Glue

The Hide glue is applied and the join is clamped and left overnight

The hole in the fret slot is plugged and re-sawn

The scratchplate is replaced

The 15th fret is replaced

A new bone nut is made and the guitar is re-strung and tested for correct intonation

Back to full health again

More enlarged photos here…

More info here…

More history here…

Vintage Guitar Repair: Gibson L 75 1932

Here’s a rare oldie in the workshop. A lovely old Gibson L 75 acoustic archtop made in 1932, one of Gibson’s rarest archtop models.

It has a body size at the lower bout of 16″ and a scale length of  24 3/4″ also a nut width of 1 3/4″. It has a hand carved book-matched solid spruce top, solid mahogany neck, back and sides and a Brazilian rosewood fingerboard. The hardware includes a compensated Brazilian rosewood bridge, trapeze tailpiece and Grover nickel-plated Sta-Tite open back tuners.

It’s in very good condition considering its age. All is as it should be apart from 1 missing and 3 loose back braces.

This is an ideal opportunity to use my new scissors jack

Inspecting the inside of any old instrument is an interesting prospect, you never know what you may find. In this case it was an old beer ring-pull and quite a lot of vintage fluff and dust.

Typically the furthest back-brace has become detached at one end

A magnet on the outside is used to manoeuvre the jack into place

The scissor jack makes an easy job of it

The other braces are much easier to access

A new matching brace is made and installed

A new set of strings, a bridge position/intonation check, a

truss rod tweak and its ready to go

Hey I sound just like Robert Johnson says Glenn of Glenn’s Guitar

Enlarged photos on Flickr

First of all, a big thank you to everyone who has used this workshop and website this year

May I use this opportunity to wish you all a very Merry Christmas and a Happy New Year.


Acoustic Guitar Setup: Gibson Hummingbird Custom Shop


This Beautiful brand new Gibson Hummingbird Custom Shop is in the workshop for a quick set-up.

Its new owner has only just taken delivery of it and wants to get it checked over.

It’s in fine fettle and is just given a truss-rod and action adjustment.

It’s given a clean bill of health

Enlarged photos here…



Soundboard          ~     Sitka Spruce
Back and Sides     ~     AAA” Figured Koa
Binding                   ~     Multi-ply Top w/ Abalone, Multi-ply back
Bracing                   ~     X-Bracing
Rosette                   ~     Double Ring w/Abalone
Bridge                      ~    Ebony Belly Up
Scratchplate         ~    Tortoise Hummingbird Inlay
Tuners                     ~    Gold Grovers Engraved Knobs


Acoustic Guitar Repairs: Guild JF55 12 String


This Guild 12 string has started to rattle badly across its bridge saddle.

On close inspection it appears that the bridge is raised. This fault is caused by the soundboard bulging or bellying in an area just behind the bridge. This is the rotational cause and effect of the bridge twisting under string tension and rising up at the back-end causing the string to lose its break point at the saddle. A classic example is the soundboard bellying behind the bridge and the soundboard sinking in front of the bridge. These problems can manifest themselves as poor intonation or string rattle across the bridge saddle. If left unchecked it could result in the bridge lifting and becoming unattached.

The cause of this problem can be due to several factors:

  • Soundboard too thin
  • Loose or weak internal bracing
  • Faulty bridge-plate*
  • Excessive string tension due to incorrect neck angle

On this fine old Guild the neck angle is as it should be. The soundboard seems to be fine with no loose struts. In reality, because this is a 12 string the soundboard thickness and struts are massively engineered. However, the bridge-plate could be at fault as it seems a little undersized to be of any great benefit. With some bridge-plates, over time and with excessive string tension and humidity changes, the glue can start to creep resulting in the plate splitting and going out of shape. In this case the bridge-plate is made of Curly Maple (odd choice) with the grain running along its length.

As all the other possible causes seem in order, the way forward is to remove and replace the bridge-plate with a slightly thicker and heavier plate made of a stiffer hard-wood.

* The bridge-plate is a wooden reinforcing patch that is glued to the soundboard directly under the bridge. It has the task of stiffening that part of the soundboard directly under the bridge and helps to counteract the twisting force from the bridge. Also it reinforces the soundboard area where the bridge-pins and string ball-ends lock into place.

The bridge is removed. The bridge-plate is dampened with a wet cloth to soften the glue. A little heat is used; the heat from a light bulb is enough to warm the plate through to soften the glue


The soundboard is clamped in a concave posture to help reinstate a flatter shape and left in a quite part of the workshop for several weeks


This short video clip takes you through the repair process

Soundtrack: Perfect World by Jeremy Sherman


Follow this link for enlarged photos on flickr…

1968 Gibson Dove: Logo Repair

This amazing old Gibson Dove dates back to 1968. It’s a clean guitar with few bumps and knocks; it’s amazing to see a guitar of this age without any splits or cracks.


However, there is one nagging issue and that’s with its logo, half of it is missing!

It was made in the days when Gibson, in their wisdom, inlayed a M.O.P. plate into the headstock, attached the logo stencils and spray-painted the negative space.  After many decades the paint has begun to flake off.  I wonder how many more of these from that era are out there with similar peeling logos.

The remedy is quite straightforward. A logo stencil will need to be created. Care must be taken in masking off the area around the stencil because of the fragile finish.

A positive logo is made up and attached. The remainder on the head is masked-off


Numerous coats of nitrocellulose lacquer must be applied to build a suitable thickness

This is the result after many layers

The new logo is carefully cleaned-up and cut-back
The logo and headstock is treated to several coats of shellac to seal,  protect and help with the aging effect.



Gibson Vintage Acoustic Restoration: Gibson l-00 1934

This Gibson l-00 dates back to 1934. It has seen a hard life so far.

When it came into the workshop for renovation work it had been set up and used as a slide guitar with a high nut and bridge and a trapeze style tailpiece .

It had also lost its finish (it could have been natural, sunburst or black) and an unknown varnish brushed on. Badly done this had collected layers of dirt over the years

The guitar top is gentle wiped over with spirit. This dissolves the immediate surface and removes most of the dirt build-up.

The Bridge

The guitar was fitted with an adjustable bridge from an arch-top guitar with the adjustable parts removed, the bottom flattened off, the two halves glued together and glued to the soundboard.  It’s doubtful, set up like this, whether the guitar ever played or stayed in-tune.

The easiest and less stressful way (for the soundboard) to remove this bridge is to plane it down to a thin strip. There would then be enough flexibility within the remaining slither to slip a wide-bladed knife under it to pop it off.

A piece of Rosewood is selected for the new bridge.

The new bridge is cut out, shaped, glued to the soundboard and bridge-pin holes drilled.

The back had been damaged years ago.

The repair look like it’s a DIY job. The crack was propped up from the inside and the crack filled with an unknown (possibly epoxy) and the whole of the back painted to match the sides. It had to go!

The Back

A repair had been badly made many years ago. The back was propped up from the inside and the crack filled with an unknown (possibly epoxy) and the whole of the back painted to match the sides. It had to go!

The old back repair propped up from the inside (viewed via a mirror through the soundhole)

Prior to work commencing and during the initial workbench examination it is decided that the old back should be removed and a new back made. Mainly to remove the inside prop bungle and also to remove the ugly repair.

Firstly a temporary cardboard mould is made to prevent the sides losing their shape. The back is removed making repairs to the internal part of the soundboard very simple.

The new back is joined, braced, shaped and stained on the inside to give an aged effect.

Once fitted, a distressed finish is created for the back as befits a guitar of this age

The guitar is set up and strung up with 12 – 54 strings.

It now plays and sound like a guitar that has regained its mojo.

Enlarged photos here…

More on l-00 history here…

Vintage Gibson Heritage Acoustic Bridge Repair

This Gibson Heritage acoustic dates back to the 1960s.

It’s in the workshop for a repair to its bridge, soundboard and bindings

•    The bridge has cracked wide open on its bass wing and lifting from the soundboard
•    The soundboard has a badly repaired split near to its scratchplate
•    The bindings are cracked and loose in places

The bridge is being held in place by two bolts through the bridge and soundboard with washers and nuts on the inside. The two bolts a hidden under two pearl dot inlays. These have to be removed to get to the screws. After attempting a few inlay removal techniques the dots would not yield and, unfortunately, have to be drilled out.

The bridge is easily removed with a wide-blade pallet knife

The bridge is repaired, cleaned and oiled

The area under the bridge is cleaned up

The bridge saddle is adjusted in height and shape

The bridge is re-glued

The Split in the soundboard is clearly visible here. This photo was taken through the soundhole using a mirror image to reveal the split.

The split is sealed on the outside and cleated on the underside of the soundboard

Another Vintage acoustic back in action

Click on the image for more pics

Vintage Acoustic Guitar Repair: Gibson Hummingbird 1968

Just off of the workbench is a 1968 Gibson Hummingbird.

It’s a lovely old acoustic guitar with a few problems. The bridge had several issues and some of the frets were badly pitted.

The Bridge

The bridge was split across the bridge pins holes

The Rosewood saddle was worn and ineffective

Also it had two ugly bolts through its treble wing(?)

And it was lifting away from the soundboard

The obvious remedy for this bridge problem would have been to make a new replacement. However, for the sake of authenticity, the owner was very keen to keep the original.

The bridge had to be removed to be re-fitted correctly.

Prior to the bridge re-fit the soundboard area beneath the bridge was repaired and cleaned up.  The bridge pin holes had become elongated over time. These were reamed out and the holes were plugged with spruce inserts.

1.    Bridge removed
2.    Initial clean-up to remove the remaining glue
3.    Re-establishing the lines
4.    Cutting back the a chisel
5.    Reaming out the elongated bridge pin holes
6.    Cutting back the spruce dowels

Initial split repair

Two holes had been drilled through the treble wing of the bridge. These holes took two bolts that attached a Barcus Berry pickup to the underside of the soundboard. When this pickup was installed, it was fitted badly and skewed between the cross-brace and the soundboard. It was decided that it should be removed. Not only was it badly fitted, it had a very low output and didn’t work too well.

  1. Measuring up for the dowels
  2. Roughing-out on the band saw
  3. Sanding into the “round”
  4. Checking diameter
  5. Dowels glued into place

Invisible repairs were made to the top of the bridge and a reinforcing strip inserted into the underneath.

1.    Routing out for the reinforcing insert
2.    Skimming level
3.    Drilling out the bridge pin holes

A new Rosewood adjustable saddle was made

1.    Drilling the adjuster holes for the new Rosewood saddle
2.    Cleaning-up and re-establishing the saddle slot

The Frets

Frets 1 – 4 had severe wear and fret # 2 was badly damaged

The 4 frets were removed and replaced. The remainder were lightly honed and re-profiled

Re-fitting the bridge

The guitar was set-up and strung up with 12 – 54 strings it’s now playing beautifully.

Repaired Bridge

Finished Hummingbird

Enlarged photos here…

Hand Made Acoustic Guitars London

Graham Parker Luthier is pleased to announce the latest guitar is the GPL Custom Edition Acoustic range.

For more pics click here…

Scroll down for process pictures

The L Edition acoustic is an attractive addition to the Graham Parker Luthier acoustic range.
It has a large 16 ¼” lower bout with a tight 9” waist and 4 ½” body depth along with the scalloped internal strutting. This gives this guitar a large bass response along with mid-range and treble clarity. The Indian Rosewood Back and Sides ensure a big projection of sound which lends itself perfectly to finger style or strumming techniques.
A curvaceous and handsome looking guitar

Features Include:
•    Select Engelmann spruce
•    East Indian Rosewood back and sides
•    White bindings
•    Circle or Mosaic Rosette (shown)
•    Herringbone wood purfling
•    Herringbone wood back strip
•    Scalloped bracing
•    Honduran Mahogany neck
•    Bound fingerboard and Headstock
•    Santos Rosewood Headstock veneer
•    Open-book Headstock shape
•    G Parker inlayed signature Headstock logo
•    Ebony fingerboard and bridge
•    Diamond fingerboard inlays
•    Fully adjustable truss rod
•    Bone nut and drop-in compensated saddle
•    Ebony bridge pins
•    Nickel Schaller tuners
•    Black or ITS Scratchplate (optional)
•    High gloss nitrocellulose lacquer finish

Process pictures

Soundtrack: Camp Rude Stumble by Ivan Rosenberg