Shoe pegs or epoxy to fill bridge holes

[Phillip Ford]

>    List
>     For years we have used shoe pegs... I can usually drill a set of 
> bridges painlessly in about an hour or so.
>
>     The problem is that no one in the shop enjoys pounding square pegs in 
> round hole except my wife Trix & she's often to busy stringing 
> etc.......  Also the pegs are getting hard to find in quantity. Any way I 
> recently tried the West systems epoxy treatment squeezing it into the 
> holes. Relatively quick & painless except for the guk/sticky 
> factor.  Ater this I immediately glue on the caps also with epoxy.
>   After it cured for about 5 days I drilled for the new pin holes but the 
> residual epoxy seems to powder up or alternately stick to the bit. I find 
> this characteristic unacceptable.  Then every other hole or so I must run 
> the bit thru some thin scrap spruce to clean the bit the drill again & 
> over & over etc. Tedious useless activity.
>   I'd be interested in someone else's technique who has more experience 
> with epoxy in this application. I like the idea of epoxies hardness and 
> all that but I do a fair amount of bridge work & can't handle the 
> aggravation. What am I missing?
>
>   Dale Erwin

Dale,

      Here's my two cents worth.  I use epoxy for filling old holes and 
bonding on the new cap.  I have used West System epoxy, but I have some 
other thinner stuff that I ordered from another supplier that I have used 
of late.  I used to try to squeegee the stuff down into the holes with a 
flexible putty knife or some such.  I now use syringes that I get from a 
lab supply to shoot the epoxy down in the holes.  These syringes have 
removable tips.  I get various sizes and use the largest one that will go 
down in the holes in question.  They're cheap, so I throw them away when 
I'm done.  I don't use fillers to make the epoxy denser.  To me this just 
makes it harder to get down into the holes and as far as I can tell from my 
own experience and from reading epoxy data sheets, the fillers don't make 
the final product any harder.  I find that I get better fill with the 
syringes and the work goes a lot faster.
      I also used to fill the holes, let the stuff set, and then level it 
off with a router before bonding on the cap.  Now I just fill the holes and 
then bond on the cap at the same time.  If I were using the West System, 
then I would use a slow hardener.  The other thin stuff that I use is very 
slow setting anyway.  I also drill the next day (shop schedule permitting).
I don't see any reason to wait 5 days.
      As far as drilling - I use the bits from Pianotek, which seem to have 
more open fluting than a regular twist drill (not sure what you call those 
types of bits).  This seems to help a bit on the bit clogging.  I use a die 
grinder for doing the drilling, rather than a drill.  The one I use is this 
Dewalt:

http://www.dewalt.com/us/products/tool_detail.asp?productID=155

I had to do some fiddling with collets in order to get it to accept drill 
bits.  It has lots of torque, so it spins up very rapidly (also seems to 
spin down very rapidly - which is a good thing for this job).  Also, very 
high speed.  I find that because it starts up quickly, it seems to be less 
prone to slip when starting the hole.  Also, because it's so powerful, it 
doesn't seem to matter if the bit clogs or not (or for that matter whether 
the bit is even sharp or not), it just punches in the hole.  With a little 
practice you just blip the handle for a second or two, it spins up the bit, 
punches in the hole, and you can pull it back out of the hole about the 
time it's spinning down to a stop.  You can go rapidly from hole to 
hole.  I haven't timed myself, but I'd say I could drill a set of bridges in 
far less than an hour.  The only thing to watch is that the bit can get 
very hot (as you might imagine).  So, I  keep a cup of water handy, and dip 
the bit from time to time to cool it down.  By the way, to give credit 
where it's due, I got this idea from Alan Vincent.  I saw him using a 
similar setup at a PTG convention.  Some time later, I tried to duplicate 
it and came up with this, which may not be exactly the setup that he had.

Phil Ford





Phillip Ford
Piano Service and Restoration
San Francisco, CA