Kawai Satin Finish

[harvey]

Brian, I can't speak to the Cory products, or whether you or your client is
right. For the rest of the story...

Most flat panel stock on current Kawai pianos is color(ed) polyester, from
the outside to the inside of the finish material.

Earlier production, such as the 550 you mentioned, used a color
polyurethane cover coat -over- a polyester base coat.

Whether early or current production, both high polish and satin finishes
start out the same. At a point in production, the various panels and
components are separated, depending on whether they are to ultimately make
polished or satin pianos. At a point, one group goes on to progressively
finer polishing (high gloss); the other gets its finish "destroyed"
(satin), by additional sanding and steel wooling to generate the high/low
pattern that characterizes a satin finish.

On polyester-only black finish, whether polished or satin, if you were to
sand the finish, the sandpaper would immediately turn black, and continue
that way all the way to the core wood (the backing material between panel
stock and finish is also black in this case).

Conversely, if you were to try the same experiment on the 550, your
sandpaper would turn black initially (black polyurethane), then would yield
grey dust (polyester) the rest of the way.

That's the "hard" way of determining which is which, but provides some
background information for you. Polyester is harder than urethane,
therefore resists scratches better. That's another test... not that you'd
want to try it.

I have seen instances where you could drag a moist white rag across a newly
uncrated satin piano, and have the rag pick up black residue. The black is
trace elements of (either polyester or polyurethane, depending on vintage)
that didn't get blown away, wiped away, or otherwise removed at the
factory. It's rare to get rid of it all in a production environment.

Why you would still get this effect on a piano of this age, I don't know.
Perhaps we're back to the Cory products and my lack of knowledge about
them. Maybe the product amalgamated the polyurethane again. In any event,
the 550 (high polish and satin) is a "sandwich" -- a core layer of
polyester, and a top finish of BLACK polyurethane.

Hope this helps rather than adding to the confusion!

Jim Harvey, RPT


At 04:23 AM 9/23/99 -0700, you wrote:
>Dear List -
>
>I had something come up yesterday during a tuning on a Kawai 550 grand
>that freaked me out a bit. The piano had a black satin finish - it was a
>1970's vintage [SN# 404185]. The customer was not interested in taking
>the things off the lid of the piano because he did not want to move them.
>He had a computer with a midi hooked to it and some other things and I
>pressed him because I wanted to inspect the sound board, bridges and
>tighten the plate bolts. He moved the stuff and understood why it was
>important. When he began to move these things, there was a good deal of
>dust on the piano lid, and trying to be helpful, I broke out my Cory
>Satin Sheen cleaner and polishing cloth and proceeded to do hime a
>service - I thought - in cleaning the piano lid for him. I was a bit
>shocked at what happened to the finish on this basically flawless piano.
>I sprayed some of the Cory on it, and wiped - and my polishing cloth came
>up black! I wiped again and as the surface of the piano was drying - the
>finish was now cloudy! Yeikes!!! The guy was not all that upset at me
>about this - to my surpirse. He worked as a piano dealer near LA for some
>time, and he being about 20 years my elder, quickly chocked it up to my
>zeal to be of assistance. He broke out a bottle of this stuff called
>"Freeman's Furniture Cream" that reversed what I had done. What happened
>there? When I suggested that perhaps he had been using a polish on the
>piano that was not the right stuff for satin and that was the possible
>reason for the advers effect of the right stuff - he quickly corrected me
>and informed me that I had the wrong stuff - I ate some crow and told him
>that was probabley right. I told him, however, that I had never had this
>kind of result with a Cory product before and I have used the Satin Sheen
>on other [new or newer] pianos and it has worked quite nicely.
>
>Any thoughts?
>
>Thanks -
>Brian, PTG Assoc.
>San Diego County Chapter