Hairline Crack

[Delwin D Fandrich]

----- Original Message -----
From: Ron Nossaman <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: February 18, 2000 9:42 PM
Subject: Re: Hairline Crack


> >Hello All,
> >
> >I'm in the middle of this, my first restringing job, and the soundboard
> >has a
> >very thin crack. Actually, it's more like a very slight separation
> >between two of the
> >panels. They're not pulling away from the ribs at all. Is there a simple
> >way to
> >handle this?
> >
> >Thanks, guys.
> >
> >Martin

> The second method is epoxy. I don't do them this way, but I don't see a
> problem with it. I think the procedure is to scrape the crack as if you
> were installing a spruce shim, but you don't need to be as careful to make
> the width and depth as uniform. Tape underneath to keep the epoxy in the
> crack, mix up the epoxy and trowel it in. Some say they mix wood dust into
> the epoxy, some don't mention it. Either way, you trim it flush when it's
> hard, just like a spruce shim.
>
> Either way, it's strictly a cosmetic repair and isn't doing a thing to
> improve the function of the board, so either method is OK.
>
> Hope this helps,
> Ron N

---------------------------

Most of our work involves replacing the soundboard, but...

I haven't repaired a crack in a soundboard with a wood shim for, probably,
20 years.  They have all been epoxy repairs.

Do fill the epoxy with a bit of wood dust.  Ours comes from a sander that we
use to sand spruce soundboard panels with.  You can make it easily enough
using a reasonably fine sandpaper and spruce wood.  Color it to match the
soundboard panel and squeegee it in.  Sometimes you have to open up the
crack a bit, other times not.  If the crack is really small, just color the
epoxy, leaving it very viscous, and run a bead along the crack and let it
flow in.  Since epoxy is transparent, if you don't color the stuff it will
make the crack stand out as a black line.  Use a reasonably thin and very
slow setting epoxy so it will penetrate deeply. Don't bother taping off the
bottom of very thin cracks, just get underneath and clean off any that runs
through an hour or so after applying it.

After you've done a couple, you'll get the hang of it.

As Ron said, it's strictly cosmetic.

Del