Electric Guitar Repair: 1968 Gibson Melody Maker



 

Luke Crowther from The Rifles dropped by the workshop a few days back. He was collecting his Gibson Melody Maker.

Melody Maker

On the Bench


This lovely old guitar was made in 1968 and has been cherished by Luke for many years until it was worked on by an over enthusiastic guitar tech and was never the same again. After that it didn’t play very well and the intonation was hopelessly wrong.

A possible reason was identified immediately

Wrap Around Tailpiece

The wraparound tail-piece was never a great idea in the first instance and this one was also tipping forward quite acutely. This type of bridge/tailpiece relies on a raised pattern to fix its intonation. Quite a crude idea which only allows for fine adjustment via two small grub screws hidden in the back end of the wraparound. This allows adjustment forwards or backwards ( or  ) and typically never gives enough movement to permit accurate intonation. 

 

Tailpiece Pull up

This has been modified at some point as it still shows the remnants  of the old tremolo system. And removing the scratchplate reveals some crude routing out for the humbuckers. Certainly not factory spec!

Open Cavity

It’s hard to say definitively but it appears that this guitar had a fixed bridge and fixed tremolo as well as single coil pickups. And at some point a previous owner has carried out all these mods.



 

Time to put it right

First thing is to remove the wraparound assembly and trem remnants.

Tailpiece removed

A modern wraparound is bought in to be fitted. This system has separate saddles similar to the Tune O Matic bridges. This will allow the intonation to be set accurately.

New Tailpiece/Adjustable Bridge Assembly

The threaded inserts that are buried into the guitar body are slightly smaller than the originals. Therefore the holes are plugged and re-drilled. To achieve this two Mahogany plugs a turn down on the lathe, inserted and drilled out.

Posthole MeasurementHole Plugs in Lathe12.85mm in Mahogany

With the scratchplate removed a few of the scratchplate screw holes are repaired.

Breakout in cavity

Scratchplate Off Plugs Drilled

With the new wraparound bridge installed and the scratchplate secured correctly the guitar is ready to be set-up.

There is some fret wear which is honed out and the frets re-profiled. The fingerboard is cleaned and oiled and the guitar is re-strung with 10-46 gauge strings.

 


 

Luke checks out the guitars new set-up

Yes he likes it, one very happy Rifleman.

 

Luke Playing a Few Licks

Luke Standing

 

Check out the band on Facebook  https://www.facebook.com/therifles

http://en.wikipedia.org/wiki/The_Rifles_%28band%29

 



 

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Acoustic guitar repair London: Gibson 1966 LG-0 (Hot Rod)





Here is an interesting project recently taken in by the workshop: a Gibson LG-O made in 1966

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This is an all Mahogany guitar: Mahogany soundboard, back, ribs and neck. This guitar was a budget instrument at the time of manufacture and sold at an affordable price as an entry-level model. The guitar has a slim neck which measures 1 9/16’’ at the nut and joins the body at the 14th fret.

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The Bridge

In 1962 with many thousands of the LG-O sold Gibson decided to exchange the standard rectangular Rosewood bridge for a plastic “belly above” type. This plastic moulded version was held in place by 4 screws that attached from under the soundboard up into the base of the bridge. This was done for ease of removal when dealing with replacements. This was upgraded in 1968 with a Rosewood replacement which included an adjustable saddle.

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 The Soundboard

The soundboard is ladder-braced with 5 lateral braces across its width. This type of bracing gives a distinctive tone that is indicative of the old acoustic Blues sounds of the 1930s. However, this system lacks structural strength and over time the soundboard can become bulged and distorted with string tension. The over large bridge-plate can exasperate the problem as these where generally made of softwood which also offered little structural strength. The LG-O was discontinued in 1974.



The Brief

Our Brief in this instance was to remove the internal ladder bracing, replace with a scalloped X brace system to give the guitar a more balanced tone and to accentuate the bass tone.

To upgrade the bridge-plate and to make and fit a Rosewood replacement bridge.



Removing the Back

In order to gain easy access to the internal bracing it will be necessary to remove the back.

This LG-O does not have an edge binding around its back outline. Therefore, a thin pallet knife is slipped between the back and the end block to start the separation. Once started a Japanese saw is used to precisely cut through the inner lining. Because of the saw’s thin blade and unique cutting motion very little material is lost during this process.

 

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Once the back is removed the simplistic ladder-brace system is revealed. You will notice that a brace and the bridge-plate are missing. I believe these became loose and subsequently lost years before. Their footprints are still visible.

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Rosewood Bridge-Plate

The remaining braces are easily removed and the internal face of the soundboard is prepped in readiness for its upgrade. An Indian Rosewood bridge-plate is made up and fitted. Rosewood is the workshop’s prefered material for bridge-plate replacement because of its strength to thickness ratio.

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Go-bars are a very handy and simple way to fit bridge-plates and braces. They are made from flexible timbers that allows pressure to be applied where needed whilst glue is drying.

The Bracing System

The bracing system is made up and glued into place piece by piece.

Each brace is made from 1/4 sawn straight-grained spruce individually scalloped.

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 Gluing the Back

Once the bracing system is completed the back is cleaned up and glued into place

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A replica of the plastic bridge is made up out of Brazilian Rosewood and fitted

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The Set-Up

The frets are showing some wear. They are honed and re-profiled and the truss-rod is adjusted.

The guitar is strung up and tested.

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 Conclusion

I’m happy to report that the finished upgrade turned out very well. The guitar has a sweet sound with a good balance. It has a warmth and depth to the bass with sweet mids and trebles. It likes to be picked as well as strummed and I suspect that it will record very nicely and with a small body guitar that’s all you can really ask for.

Full size photos available here on Flickr





Fender Bass Repair : 1969 Fender Precision Bass Truss-Rod Repair





On the workbench is a 1969 Fender Precision Bass with a problematic playing action. The action is high and the bass is very uncomfortable to play.

It was bought through a popular online auction and was brought into the workshop for an assessment after the new owner had tried various adjustments but failed to make the bass more playable.

It had spent most of its life in its case inside a closet. This is confirmed by its amazing condition. The finish is bright and clean with very little markings or lacquer cracks. The hardware is all original and unusually the bridge and pickup covers are still present. I suspect that it was put away and forgotten about because it is such an effort to play. This would account for its immaculate condition.

Click image to enlarge



Fender Truss-Rod

On all early Fender guitars the truss-rod adjuster is at the body end of the neck. Upon inspection it is apparent that the truss-rod is not working as well as it should. Any adjustment has little effect on the neck.

Upon testing the truss-rod, it appears that the adjusting screw reaches its limit before any changes to the neck are effective.

The prognosis is that the truss-rod is either broken internally or that the adjusting nut is ineffectual in some way.

The remedy is to replace the truss-rod.

This is a problematic job as this would require the rod to be removed without removing the fingerboard. It is not possible to remove a Fender style fingerboard without changing the nature of the neck beyond all recognition. This would detract for its originality and drastically devalue the guitar.

A Fender truss-rod is made from a piece of round section steel with a “T” soldered onto one end (the truss-rod fixed point )and a thread tapped onto the other end to accept the adjusting nut. Once fitted into place, and when the nut is tightened, the adjusting nut pushes against a fixed internal washer which is part of the inner channelling that the truss-rod sits into.

It is decided to create an opening in the fingerboard directly above the truss-rod fixed point and expose the “T”.  Once exposed, the “T” can be severed and the rod extracted via the body end on the neck.

A magnet stack is used to locate the end of the truss-rod

A section of fingerboard is scribed through and removed thus revealing the “T” fixed point

The “T” is drilled through and severed

The rod is extracted through the body end of the neck

Testing the truss-rod once it has been removed, it is apparent that the adjuster is ineffectual. As the adjuster is tightened it has the effect of ejecting the screwdriver (very frustrating).

Click image to enlarge


A new rod is made up using a piece of silver steel and a different style of adjuster. This is inserted into the headstock end of the neck and fixed. Silver steel is a tougher material and more likely to allow for extra torque that may be needed on final adjustment.

The fingerboard piece is replaced

The area smoothed over and cleaned up

Frets 1 & 2 are replaced and a new bone nut made and fitted.


The Conclusion

I am pleased to report that the truss-rod works well and has made a vast improvement to the basses playability. The initial cost of a repair such as this is easily justified due to the overall value now put on this fully functional  ’69 Fender Precision bass – all original and in excellent condition – in short a splendid bass.

The bass is now permanently out of the closet and enjoying its new lease of life by its new owner.

More on P. Basses here




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…




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.

 

 








Guitar setup: Acoustic Guitar Repair: Fret Dressing a Martin D 28

This Martin HD 28 is in the workshop for a full set up and fret dress. It dates back to 1987 and this is its first serious set up.

The frets are showing signs of wear and tear. Also the fingerboard has started to show signs of wear and has a few grooves worn into it around the lower end on the treble side.
The fingerboard wear is tackled first. It is skimmed between the frets and the worst of the grooves filled and smoothed.

Next comes the fret dress.

The truss rod is released to ensure that the fingerboard is flat and level. The neck is supported along its length. The body work is protected and masked off.

The fret tops are skimmed with a fine honing stone to remove all fret wear and grooves. Also to ensure all frets are a uniform height.

The fingerboard is masked off. Each fret is re-profiled.

Each fret is polished up to 2500 grade Silicon Carbide paper and then finely polished with burnishing cream.

The guitar is strung up and the truss-rod reset for Martin medium gauge strings.

And it plays like a dream.

Meet Colin the happy owner.