Help with splitting bass bridge

[Barrie Heaton]

Hi Bill,

This is how I do bass bridges,  can be done on site


First take a rubbing of all pins, then release the tension of the base
strings in the effected area, not necessary to release the tension on
unaffected area.  Pull out pins in the split section.  With a V shaped
cutting chisel the type you would use for your shims on a soundboard.
Cut a groove approximately 25mm deep and 5mm thick you can use a router
with the appropriate cutting tool.  You will find your chisel cuts it
easy

Make sure that you remove at least two good
pins which are not in the split area, take your groove from their to
the end of the bridge.  Cut a piece of Beech in to a V shape and saw to
the appropriate length.  Make sure that the V shape piece is deeper than
the 25mm  groove and that the angle of descent of the V is the same as
the groove.  Mix some epoxy resin.  Place the epoxy resin on your Beech
Shim and tap down in to place with the shaft of your hammer, take four
strings of equal spacing and reattach to the hitch pins and apply
equal tension.  This will ensure, that the shim stays in place and well
bedded down.  Remove any excess glue being careful not to get any on
the strings  let it dry.  Remove tension from base strings
and plain down the excess shim,( or cut with a knife or  chisel) smooth
off.  Re burnish the area reposition your template you made earlier with
the rubbings use a needle punch and punch the positions for the bridge
pins.  Measure old bridge pins and pilot holes to the appropriate size,
not forgetting to drill at a slight angle to introduce side angle.

  I find a hand drill much easier to control than using an electric
drill.  Knock the old pins back in to place or use 1" new ones file pins
off replace strings pull up to tension.    If you've
done it right no one will ever know you were their.  There should be too
faint glue lines and if you have chose your materials wisely it should
blend in nicely I gave beech just as an example hope that makes
sense.

If you do not have a V shaped
cutting chisel make one,  out of an old screwdriver


Barrie,

In article <970106162039_1491837729@emout17.mail.aol.com>,
WMaxim@aol.com writes
>List -
>
>Hoping to save the customer the expense of installing a new bass bridge, I
>tried removing the affected pins and working in epoxy before pushing the pins
>back in and cleaning up the surface.  It set up for a week before I put the
>strings back.
>
>The situation was different from any I have run across.  There was no
>buzzing.  The only symptom was that about an octave of the bichord strings
>had dropped about 50 cents.  Inspection of the bass bridge showed, not a
>crack in line with any of the pins, but about an octave of them had moved.
> The impression I first had was that the offset had been too great.
>
>On closer examination, it became plain that the wood grain was not parallel
>with the surface of the bridge but was angled from the shelf toward the
>surface.  Being somewhat swirly in that area, its direction matched more the
>angle of the pins; each affected pin was lifting up the grain as it
>approached the surface.
>
>I was uncertain just how well epoxying the pins back would work, and sure
>enough I have a call from the customer that those strings are settling out of
>tune.  I had warned her that that could happen just from the loosening and
>retightening in my work.  However, I paid special attention to settling them
>in and am sure it is the bridge pins lifting the grain again.
>
>Any advice at this point?  Just keep pulling back into tune until it settles
>down?
>
>Bill Maxim, RPT
>





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Barrie Heaton                                  |  Be Environmentally Friendly
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