From Gregor _ <karlkaputt@hotmail.com>
On a German piano forum is an ongoing discussion about that topic (in German, of course):
http://www.clavio.de/forum/klavier-keyboard-kaufen-reparieren/16878-schellack-ausbessern.html
In the first posting you can see some pictures and some links to more pictures. The colleage made it like this:
First he "sanded" with a sanding sponge: http://www.dreamline.at/gipsshop/images/product_images/info_images/49087.jpg
You can see that sponge in action here: http://www.youtube.com/watch?v=ZSSIKJNzKtM
Then he made the first pass with black shellac and oil, but with less alcohol, so that the polish is thick
After 3-4 days he made a second pass, but now with more alcohol and lesser shellac, so that the melange is thinner.
After further 3 days he made the third pass without oil, lesser shellac and more alcohol, but never too thin/liquid. This time he used not black, but transparent shellac.
After 10 days he polished with a high gloss polish.
Gregor
------------------------
piano technician - tuner - dealer
M?nster, Germany
www.weldert.de
From: karlkaputt@hotmail.com
To: pianotech@ptg.org
Date: Mon, 28 Jan 2013 14:49:28 +0100
Subject: Re: [pianotech] How to remove scratches
Doug, thank you for your detailed answer. I am familiar with French Polish. During my apprenticeship I completely polished some pianos, but that?s more than 20 years ago ;-) I was just wondering if that K?nig stuff is something special or just shellac. Usually I would prepare the surface by sanding and use oil for polishing and some kind of pore filler (Bimsmehl is the German word, could not find a translation for that) and after polishing I would use some benzoic acid to remove the oil. But using a very special stuff in a one step polishing procedure sounds quite charming :-)
Concerning removing scratches on poyester: no, French Polish does not work. The best method on polyester is just very fine sanding (if needed at all, depends on the depth of the scratches) and polishing with a machine.
Gregor
------------------------
piano technician - tuner - dealer
M?nster, Germany
www.weldert.de
> Date: Sun, 27 Jan 2013 21:37:48 -0500
> From: classicpianodoc@gmail.com
> To: pianotech@ptg.org
> Subject: Re: [pianotech] How to remove scratches
>
> Gregor,
> It is strange that the German Konig site does not advertise Special
> French Polish. I checked my bottle and it is imported. The phone
> number in Europe is +49 (0) 61 01 - 53 60 0.
>
> You should be able to get the Special French Polish in Europe. The
> method is much simpler than traditional French Polish as a lubricant
> is included in the shellac so that it is only one step. Make a pad
> with a ball of wool or gauze and wrap it very tightly with a 20 cm
> square of well washed old Tee shirt that is stretchy. I use a golf
> ball sized pad or smaller. There should be no creases or folds in the
> application surface. On a new pad, first open the cover cloth and wet
> the gauze well with Konig French polish but not so that it will drip
> when squeezed hard. Put the cover back on and put about 10 more drops
> on the stretched surface of the pad. The pad should be just damp
> enough so that when you tap it on the back of your hand, it is just
> damp. Keep it stretched by twisting the remaining cloth on the back
> of the pad and hold onto the twisted part. Practice on a scrap piece
> of a finished piece of wood like an upright piano top or key cover or
> other furniture piece. It should be at least 20 cm square. Start by
> coming down on the wood from a low angle without stopping- Like
> landing and airplane. The application should be in a circular motion
> that is fairly rapid. You can make overlapping circles and move around
> until the whole piece is finished. The pad will leave a slight trail
> on the finished area. This is drying shellac that should be drying
> almost instantly. You will have to replenish the pad with about 10
> drops of polish every few minutes. Watch for the trail of drying
> shellac. When it does not leave a trail, replenish. You can work a
> piece with several applications on the same area before it starts to
> get a bit sticky. This may take up to 30 minutes of polishing. You may
> be done before that happens. If it gets sticky, let it dry for about
> 30 minutes and resume polishing. When you have polished it
> sufficiently, take some long swipes with the grain to remove any swirl
> marks. These should be minimal. Let it dry and you are done. It can be
> waxed or not the next day. This is a very brief description. I have a
> video but have not put it on the web yet for lack of time and
> knowledge of the process to post it. It is on my to do list.
>
> I am sorry that there is not one on the web. I have looked and have
> not found a decent one. Konig does sell a rather good video on this
> and other techniques that is well worth buying. It also tells how to
> do scratch and dent repair with Konig hard wax and retouching with
> their markers and other techniques. I have been doing this kind of
> work for years and learned some good techniques from their video. Good
> luck. Be sure to practice on one or two pieces first. It does not take
> long to learn, even on your own.
>
> Doug Gregg
> Classic Piano Doc
> www.classicpianodoc.com
>
>
>
> Message: 3
> Date: Sat, 26 Jan 2013 11:15:26 +0100
> From: Gregor _ <karlkaputt@hotmail.com>
> To: "pianotech@ptg.org" <pianotech@ptg.org>
> Subject: Re: [pianotech] How to remove scratches
> Message-ID: <DUB104-W22898FC8B35B3E8EB74575D41A0@phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> Doug, that?s interesting. I found the USA website of K?nig and found
> French Polish. But on the German Site there is no Schellack or French
> Polish. I attented a class at K?nig about scratch repair with the
> focus on Polyester, but all other surfaces were tought as well. I
> don?t remember that they offer French Polish in Germany.
>
> How do you use the French Polish? As a quick and dirty method just
> applying with a bale or do you prepare the surface? What would you do
> with the fallboard example form Michael?
>
> Gregor
>
> ------------------------
> piano technician - tuner - dealer
> M?nster, Germany
> www.weldert.de
>
>
> > Date: Fri, 25 Jan 2013 11:36:20 -0500
> > From: classicpianodoc@gmail.com
> > To: pianotech@ptg.org
> > Subject: [pianotech] How to remove scratches
> >
> > Michael,
> > I repair such scratches all the time with French polishing. I gave a
> > seminar on it in Seattle. It is quite easy to do. It works so well for
> > this kind of thing because it only adds a thin layer of shellac and
> > there is no risk as there is with sanding and polishing. The beauty of
> > French polishing is it fills the scratches selectively without
> > building up finish on the non-scratched area. That is, it fills the
> > valleys up to the top of the hills leaving a glass-smooth surface. It
> > is also very safe and I often do it in the clients music room over an
> > Oriental carpet with no concern of odor or spills or overspray. I use
> > Konig Special French polish from www.konignorthamerica.com. Or google
> > Konig french polish. They also have videos.
> >
> > The alternate quick and dirty solution is to spray the fall board with
> > several coats of clear lacquer. Then fine sand and polish the new
> > lacquer without the danger of damaging the black underneath. I find
> > that polishing lacquer to a high polish is not that easy. I would sand
> > it with 400 and then 600 paper with water, dry, and then give a final
> > coat of spray that lays down flat. Do that outside if possible. The
> > fumes are strong. French polish still comes out better and is three
> > times as fast. There is no waiting for lacquer to dry and no sanding.
> >
> > See my web site to see French polishing before, during, and after.
> > www.classicpianodoc.com
> >
> > Doug Gregg
> > Classic piano Doc
> > Southold, NY
> >
> > Message: 1
> > Date: Thu, 24 Jan 2013 17:00:01 -0800 (PST)
> > From: MICHAEL MEZHINSKY <pghpianotuning@yahoo.com>
> > To: "pianotech@ptg.or" <pianotech@ptg.org>
> > Subject: [pianotech] How to remove scratches
> > Message-ID:
> > <1359075601.24779.YahooMailNeo@web160205.mail.bf1.yahoo.com>
> > Content-Type: text/plain; charset="iso-8859-1"
> >
> > Hello,
> > Can anyone suggest how?to remove scratches on the black lacquer finish
> > fall board on a 1932 piano or make it look better?
> > The picture is attached.
> > Thanks for your help.
> > Michael Mezhinsky RPT