need to id finish type

[Wild Turkey]

Redoing some high quality '60's oak furniture and need to id the finish.

So far I've found acetone will soften it and mineral spirts won't.  

What other tests can I make to get a good idea of what it is?

And will polyurethane stick to it? (I'll probably be sanding it first, but possibly not in some areas)+

{backstory: LOML decided the bunk beds of the suite needed to be stored in unheated barn.  Not one of her best ideas.  Sanding, etc to get them back into grandkid condition.}

[Gary G™]

If you purchased it, it’s more than likely a sprayed Catalytic lacquer.

[jteneyck]

Most likely some form of lacquer.  Whether or not it's catalyzed I would spray a light coat of dewaxed shellac (rattle can or Sealcoat) on it before applying any form of polyurethane.  And first be sure to wipe it well with mineral spirits before any finishing to remove any wax.  

John

[Wild Turkey]

That's what I suspected.  It's been so weathered I've been sanding much of it off and restaining the wood before spraying on some finish.  Now that I'm getting ready to work on the bigger pieces that were stored in heated basement I'll need to use some shellac where I refinish.

Thanks for the good info.