Epoxy Repair to bridge top

[Mike and Jane Spalding]

Dale,

I just finished re-pinning a bridge, wet.  I followed the procedure in Bill Spurlock's Journal article of a decade or so ago.  Remove old pins, plane bridge top to bottom of string grooves, re-notch.  Coat inside of holes with epoxy using piano wire.  Dip new pins in epoxy and slip/drive into holes.  Brush excess epoxy to coat bridge top and notches.  Dip brush in lacquer thinner, brush top (not notches), wipe brush in rag, dip in lacquer thinner, repeat, to penetrate bridge top with thinned epoxy and remove excess.  (I don't like the resultant thick glossy epoxy coating on the notches, so will rub the gloss out with steel wool, and next time will do the solvent brush thing on notches as well as bridge top.)  Let cure, paint the bridge top with DAG thinned 2:1 with DN Alcohol.  But overall I'm very satisfied with how it looks - won't know for a couple months how it sounds.

Mike

----- Original Message ----- 
From: <Erwinspiano@aol.com>
To: <pianotech@ptg.org>
Sent: Monday, December 16, 2002 8:37 PM
Subject: Re: Epoxy Repair to bridge top


> In a message dated 12/16/2002 5:16:51 AM Pacific Standard Time, 
> RNossaman@cox.net writes:
> 
> > Subj: Re: Epoxy Repair to bridge top 
> >  Date: 12/16/2002 5:16:51 AM Pacific Standard Time
> >  From: <A HREF="mailto:RNossaman@cox.net">RNossaman@cox.net</A>
> >  Reply-to: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
> >  To: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
> >  Sent from the Internet 
> > 
> > 
> 
>               Ron And all who responded
>                Thanks for sharing your collective think tank type ideas
>            
>                Yes, I now realize I'll have to drill and drive which is more 
> trouble but I wanted to use the epoxy as a finish as well as structure 
> re-enforcer. So in this case I'm committed to this  technique. To all who 
> drive the pins in wet,do you brush the excess onto the top and redag or what? 
>   Is it just left glossy or what? 
>          At this point ,although I'm going to more work, the satin rubbed 
> epoxy top and notches allows for a quarter sawn visual extravaganza, it looks 
> stunning and functionally it's harder. The Stwy D bridge I just did in 
> shellac has the same appearance and dang shellac is very tough stuff too. 
> Just try sanding it.
>     Tuesday I'll drive in some pins and see how it goes. The original tenor  
> pin size were 7s top to bottom so I didn't like the idea of drilling for 8s. 
> With caps of older wood I have concerns of splitting with increased potential 
> for compression.
>            Thanks all
>         Dale Erwin
>     P.s. Hey What about re-plating the bridge pins at the platers to increase 
> the diameter a thou. or so. In some cases it would eliminate the epoxy. Same 
> idea as no 3 and 1/2 tuning pins now sold by piano tech.
> 
> > 
> > 
> > >  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.
> > >     Dale Erwin
> > 
> > 
> > Hi Dale,
> > I put the new pins in the original holes with epoxy in one shot. No 
> > pre-filling, cure, and ream to fit. The gap filling properties of the epoxy 
> > 
> > take care of the fit. I've already got the bridge top flattened and 
> > re-notched, and the pins more likely push in rather than having to be 
> > driven. What driving there is usually is to even the pins up at finish 
> > height. Dry brush cleanup takes care of what oozes out. Alternately, 
> > installing pins dry and CA from on top soaks in and solidifies the cap and 
> > the interface between cap and pin.
> > 
> > In this case, if you've already filled the holes with epoxy - now cured - 
> > there isn't any place left for more epoxy to soak into, so you're probably 
> > better off putting them in dry after reaming to fit.
> > 
> > Ron N
> > 
> > _______________________________________________
> 
>