Gibson Plastic Bridge Replacement.

Discussion in 'Acoustic Instruments' started by David Collins, Jan 25, 2015.

  1. David Collins

    David Collins Member

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    Just finished editing a video last night on our approach to replacing the old plastic bridges found on 60's Gibsons. Tried to make it short as possible, so it's far from comprehensive, but rather a lot of little glimpses in to many steps along the way.

    http://youtu.be/HgkcA9ikHFQ
     
  2. walterw

    walterw Gold Supporting Member

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    most awesome!

    especially the micro-rabbet trick; that's really all you need to keep the bridge fully locked in place while clamping?
     
  3. David Collins

    David Collins Member

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    Yup. This is actually a method I learned from Steve McCreary at Collings. Traditionally the options were to cut the finish to the full edge of the footprint, which even if can be done invisibly (quite a challenge) still leaves the finish at greater risk around the perimeter with stresses and humidity shifts down the road. That, or leave the finish inside the perimeter a bit (standard method for most makers), which leaves the bridge sitting on a shelf and a gap between the wood surfaces, which does not provide for the most enduring joint.

    The primary goals of this are providing solid wood to wood joint contact while leaving the outer edge resting just over the finish for a clean safe joint. The locating function is just a convenient peripheral feature.

    Not my idea though, but rather one borrowed from Collings.
     
  4. walterw

    walterw Gold Supporting Member

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    makes sense;

    and the trick for leaving just enough finish inset on the top to fit the shelf in the bridge edge? are you just chiseling it by eye?

    i've always done the first "traditional" method, with the idea that if you see a little something at the corner there, well the bridge was coming off the guitar what the hell do ya want?

    better that than having the two surfaces not properly mate and compromising the strength.
     
  5. zombywoof

    zombywoof Member

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    While those plastic ADJ bridges are possibly the worst idea Gbson ever came up with, you see the second biggest mistake at about 1:30 into the video - the laminate bridgeplate that is large enough to qualify as a piece of furnture. It does not matter what the bridge is made of if the vibration gets cut off at the bridge plate. You hear much the same from Martin guys about the switch from the maple to a large rosewood bridge plate at the end of the 1960s. If you do not swap the plate that is in there for a standard maple plate when you change the bridge you are only half way there. It continually amazes me how many people change bridges on Gibsons but do not give any thought to the bridge plate.
     
  6. gear007

    gear007 Member

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    Nice work Dave!
     

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