Guitar companies are making models for the masses while the instruments artists play are typically modified to get special tones in the instrument rather from amps or software (see the 'Schematics' page). All companies have custom shop brands or options where you can get this done for $5 - $10 thousand +. Since 2008 a lot of info has been available on the internet revealing schematics and modifications to get the artist tones. This opens the window to have special instrument tones in your guitar or have a mod guitar that has the features of a $$ custom shop model. This blog will pick a few projects to get classic tones and increased flexibility on board. Not for everyone but it is a matter of style, understanding what goes into a custom shop $10 thousand guitar and why great players use a hand full of onboard modifications to trademark their sound.

Second Hand -"It's probably a well-known story . . . I went into a shop in Nashville called Sho Bud which was owned by Buddy Emmons – the famous pedal steel player – and they had things like Rickenbackers in the front of the shop going for quite high prices. In the back they had this second-hand department, and there was a row of Stratocasters, and I bought them all. Blackie was made out of three of these guitars – the body of one, the neck of another and the pickups of another." Eric Clapton



Martin Cracked Bridge Repair - Cracks Between Peg Holes




Replace or Repair

Bridge repairs on Martins are not unusual and typically involve removing the bridge and replacing the piece.  In this case there is a crack in an ebony bridge between the peg holes.  



Many luthiers would replace this piece since it is likely at some time a replacement will be needed. There are a few things to check to see if replacement is needed.  Here is what Dan Erlewine has to say about this repair- seems to say you can fix or replace:

























The bridge cracks occurred from: 

  1. Pressing the pins in to hard - see the Martin 'care instructions which reference this as a cause
  2. Using the wrong bridge pin size
  3. Top warping from dryness which will make the top convex - the center sinks more than 1mm.  This will cause the bridge to separate from the top usually along the back of the bridge (opposite the sound hole).  Another symptom of convex warping is string buzz since the bridge is now lower to the neck.
  4. Top belly forming in the area of the bridge that is extreme enough to cause the bridge to stress and separate. 
Other considerations:


  • If the bridge is lifting then it should be removed and reglued or replaced.  
  • If the bridge has lifted then the bridgeplate support under the bridge inside the guitar may have separated from the top also.  The condition of the bridgeplate should also be checked.
  • If the top is warped also check the back
  • Do not correct the belly deflection.  Most spruce tops and other woods form a bridge bulge which contributes to the aged tone. 


 OK so what needs to be checked:

 Has the bridge lifted?  Check this by using wax paper or the flap of a paper string envelope and see if you can slide it under the bridge along the back, sides, corners and front.  If you get the paper to go in more than a millimeter or two then consider removing the bridge and regluing. In this case the bridge is firm with only small area under the corners that has separated.

 Condition of the bridgeplate- In this case firm and in good condition with the bottom holes the proper size.

 Top warping- The top is warped as shown below and it was corrected with several days at 50% humidity.
Here the low points are about 2mm and less at the center bulge

After several days wrapped in plastic with internal humidifiers
the maximum drop is 0.8mm and the center is slightly higher than
the sides






















Fixing the Cracks

The steps are the same as repairing other small wood cracks:

  1. Fill with sawdust
  2. Fill with thin cyanoacetate glue
  3. Sand
  4. Oil finish to match 
Sawdust from a piece of ebony.  CA is thin and applied
with a thin wick top from Stewmac




















Tape off crack area and place paper towels inside
guitar under peg holes to catch glue and saw dust






Fill in cracks with sawdust



Multiple applications of CA and sawdust building a
small bump over the cracks. Apply several layers 
waiting 10-15 minutes in between
After sanding with 600 and 800 wet dry paper and a few drops of mineral oil


Posted by No comments:
Labels:
Subscribe to: Posts (Atom)