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

Image  Image

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.

Exif_JPEG_PICTURE

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.

Image  Image

 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.

 

Image Exif_JPEG_PICTURE Image

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.

Image



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.

Exif_JPEG_PICTURE  Exif_JPEG_PICTURE

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.

Image  Image  Image

Image  Image

 Gluing the Back

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

Image

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

Image

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.

Image  Image

Image

 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





Advertisements

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