[pianotech] varnish over lacquer

[Ron Nossaman]

On 8/26/2012 7:49 PM, David Love wrote:
> It seems that I've heard that there are no problems with varnish over
> lacquer but there are with lacquer over varnish.  True or untrue?

Maybe not no problems, but varnish over lacquer isn't chemically 
reactive. Lacquer over varnish, however, isn't a good idea. At worst, 
the varnish underneath will wrinkle up and slide off in sheets as the 
varnish underneath turns to goo. On average, it will separate as those 
mini tectonic varnish plates migrate on the underlying goo. At best, 
there is no at best. Even if you get away with it, it's really delicate 
and will probably attack you later anyway after you have even more time 
and money invested. At least that's the cellulose nitrate. Other 
formulations, particularly the waterborne, may be more benign. I don't 
know about them.

Ron N