Blisters on finish

[harvey]

Bzzt! Close, JimRPT, real close, and applicable if it were red, yellow,
black, white, or anything other than [any] clear finish over certain
natural veneers.

What Carol describes sounds like a situation that also happens to rosewood.
If I'm right, it has to do with residual oils in the veneer that prevent a
good bond twixt the veneer and the finish (x-urethane/poly/whatever). Even
though the veneer is very thin, certain areas contain oils that continue to
leech toward the surface of the veneer. Consequently, over time, the finish
generates the ugly blister(s), and yes, since the finish is being held on
by oil, given the slightest provocation the clear coat will fall off.
Often, the piece that was once on the piano and now in your hand will feel
"slick" to the touch, almost like it has a spray coating of silicone,
Teflon... or 'Pam' cooking oil.

On the positive side, it seems to either happen or not. IOW, if the finish
survives xx months without the effect, given the same environment, etc.,
chances are slim of the condition ever occurring (cannot be considered a
"common" situation).

On the negative side, I've seen attempts at repair, some better than
others. What I've yet to see is a reliable (long-term) repair that looks
good and/or, to your point, lasts. The actual repair process involves
cleaning a perimeter area larger than the damage, using a solvent in an
attempt to remove residual oils (hoping they have all made their way to the
surface), then feathering in a new clear-coat finish with whatever is
available locally -- water-white lacquer, etc.

Think of this in the same terms as, say, placing a piece of wood under a
Harley-Davidson for a week or so; and then trying to apply a coat of paint
over the resulting oil slick. Chances are good the paint won't stick.

Jim Harvey, RPT
- Someone who had to deal with the phenomenon for a moment in time.

At 12:31 AM 9/22/99 -0400, you wrote:
>
>In a message dated 9/22/1999 12:11:12 AM, carolb@earthlink.net writes:
>
><<"Or is
>this just another one of those problems associated with "gray market"
>pianos.">>
>
>Carol;
> No this isn't "one of those problems" and most of the others aren't either 
>:-)
>When this piano was made Yamaha and everyone else was using standard cabinet 
>construction procedure for their polyester pianos...that didn't work due to 
>the expansion and contraction that we all love so!!  Newer models of Yamaha 
>and Kawai, Young Chang, etc. use a fiber board/synthetic dense underlayment 
>for their poly finishes now and doing so has solved this blistering/cracking 
>problem.  The problem can be repaired very simply, but it will happen again 
>in all probability.
>Jim Bryant (FL)
>