Epoxy Repair to bridge top

[Bill Ballard]

At 11:58 PM -0500 12/15/02, Erwinspiano@aol.com wrote:
>I was planning to ream the holes with the apropriate size bit and 
>drive in a new pin. The reason I've avoided this process in the past 
>has been because of the untidy out come of sticky epoxy ever where a 
>s I'm pushing bridge pins into it and having it come gushing out 
>everywhere and trying to clean it up.

For starters, I be careful not to put more epoxy in the pin hole than 
you were absolutely certain was going to make a gap-filling film 
between the (say) .075 pin and the .076 hole. Which is not much more 
than can be carried on a piece of music wire and applied to the walls 
of the hole with same. How much you'll want on the wire can be 
determined in the first few holes. If the pin climbs back out of the 
hole after you've finished driving it, there's too much resin in the 
hole. If a pin climbs back out while your driving its neighbor, 
you've definitely got too much.

We all have the mental picture of underground fissures in the bridge 
root, running from hole to hole, and an accompanying picture of a 
hungry-man sized dose of epoxy being pumped through the system of 
cracks as the pin is being driven into the hole. But in most 
instances, do we know just how extensive that maze of subterranean 
cracks is, and how much epoxy (above and beyond the amount necessary 
for the gap filling film) we'll need in the pin holes? No. 
Considering what a nuisance surplus epoxy in the holes is, I'd tend 
to be on the conservative side when applying the epoxy to the holes. 
Of course the first few bridge pins will tell you alot.

Bill Ballard RPT
NH Chapter, P.T.G.

"Filing the bridgepins sure puts a sparkle on the restringing, but is 
best done before the plate is re-installed"
     ...........recent shop journal entry
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