Cloudy white in poly finish.

[rob.]

I bought a guitar on the week end, its got a poly finish over black. On the head stock there is a patch that has gone milky/cloudy white.
I don't know how long its been like this or what caused it, the guitar was made in 2002.
Is there a way to fix this without stripping it? Its right above a logo transfer so sanding isn't really an option.

 

[profchris]

What follows is all guessing, without seeing it.

I think this probably means the poly finish is losing adhesion there. Try finger pressure on the cloudy patch to see if you feel movement, or if the shape or degree of cloudiness changes.

The other possibility is contamination underneath at that spot, or from the logo itself.

Either way, I know of nothing you can do to poly to fix this, other than stripping and refinishing. Poly is impervious to pretty much everything other than edged weapons!

There's just a chance that a crack in the finish has let moisture in, in which case gentle heating with a hair dryer might improve it - worth a few minutes to try.

I only finish with shellac or Tru-Oil, so this is second hand info but I believe it's accurate.