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Gibson B-25: New Bone Saddle

1.0 gibson b 25 bone saddle 1.2 gibson b 25 bone saddle
1. Gibson B-25 Adj. The “adj” designates a ceramic saddle which may be “adjusted” via. 2 machine screws located at both ends of the saddle. Unfortunately, the bridge on this guitar needs to be replaced. After I do that I’ll fabricate a new drop in bone saddle. 2. Preparing the Saddle Blank begins by flattening one side of the bone blank. I’m using 180 grit sandpaper on a dead flat granite slab to achieve this.
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3. Flattening the Bottom of the Saddle is also achieved on the granite slab. I’m holding the flat side of the blank against a square block of steel. This insures that the bottom and one side are square. I’ll mark the square surfaces with a pencil before I thickness the blank. 4. Thickness Sanding the Saddle with the luthier’s friend precision sanding station is quick and accurate. I’ll run the blank through the thickness sander until it is a few thousandths of an inch too thick. Then I’ll complete the process of thicknessing by hand on the granite slab.
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5. Crowning the End of the Saddle on the belt sander is quick and accurate with the assistance of the squared steel block stabalizing the bone as I round the end with the shop’s disc- sander. 6. A Properly Shaped Saddle End.
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7. Cutting the Saddle to Length starts by laying out a square cut line. A few seconds on the disc sander and I have the saddle’s length established and both ends rounded. 8. Marking the Saddle for Height. After I’ve test fitted the saddle in the bridge’s saddle slot, I traced a line accross one face of the saddle marking the point on the saddle where it protrudes from the bridge. Now I’m marking the height of the saddle at both e strings. In general, when I’m making a new saddle for a guitar with a correct neck angle, I want my rough saddle protrusion above the bridge to be 3/16″ on the 6th string and 1/8″ on the 1st string. I’ve marked the saddle accordingly above my pro- trusion line.
1.9 gibson b 25 bone saddle.jpg 2.0 gibson b 25 bone saddle.jpg
9. Marking the Saddle for Height Cont. The fretboard of this guitar has a 12″ radius. Therefore, I’ll use a radius guage to trace a 12″ radius accross the saddle. The radius must cross my height marks at both e strings. 10. Shaping the Top of the Saddle with the disc sander is quick and easy. The bed of the shop’s disc sander came from the factory with a corrugated surface. In order to sand small parts, I filled in the corrugations with epoxy. The disc removes material more aggressively as I move away from the center of the sanding disc. This allows me to achieve both rough and fine cuts with the same disc by simply changing what portion of the disc I’m sanding with.
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11. Laying Out the Saddle for Compensation. I’ve marked the locations on the saddle where each string will make contact. Now I’m marking the top of the saddle with lead to use as a visual aid while compensating the saddle. 12. Compensating the Saddle begins with a Swiss needle file. In preparaion of this step, it is helpful to note the sate of a guitar’s inton- ation with a strobe tuner before removing the saddle which is being replaced.
2.3 gibson b 25 bone saddle.jpg 2.4 gibson b 25 bone saddle.jpg
13. Sanding the Saddle by hand with 600 grit sandpaper gets rid of the file marks. 14. Polishing the Saddle will give it a nice shine. I’m using micro-mesh abbrassive pads to achieve this. These little polishing pads achieve a 12,000 grit mirror finish in seven steps.
2.5 gibson b 25 bone saddle.jpg 2.6 gibson b 25 bone saddle.jpg
15. A Compensated Bone Saddle. After a test fit, I found the action was a bit taller than I would like. This just about always happens as I try to make the saddle too tall with the intention of making my final adjustments by removing material from the bottom of the saddle after a test run. 16. A New Bone Saddle paired with the new traditional wooden bridge have significantly increased this guitar’s volume and tone.