Question on thick Fender finishes and nitro

Since my belief is that the notion of finishes effecting tone is an absurdity unworthy of discussion to my mind the sole benefit of a nitro finish is that because of nitros ability to melt in minor dings are more easily repaired than they are with poly. On the other hand poly being a harder substance is less likely to get dinged in the first place and if the finish is thick that's even better since it allows for the possibility of being able to sand and buff out minor dings without going through the finish. I have two Gibson nitro finished guitars in my collection but given the choice I'll take a nice thick poly job every time.

 

A lot of Fender USA nitros are thicker than most, if you count the poly-undercoat. But even then, they're much thinner than a Fender USA poly.

 

A finish is intended to protect the wood from the elements and enhance its appearance. Without a finish the wood would be relatively unstable and will try to maintain equilibrium with whatever the surrounding humidity conditions are. In humid climates, the wood will swell. In dry climates, it will shrink. In extreme conditions, the wood will split.

The idea that the wood needs to breath actually means that some amount of humidity entering and exiting the wood should keep the wood within its elastic limits and maintain equilibrium and dimensional integrity. A finish accomplishes this in one of two ways... sealing off the wood from humidity altogether (polyurethane and polyester finishes) maintains the wood's current moisture content and prevents it from changing. Oils, Shellacs, French Polish, Varnishes or Nitrocellulose Lacquer allow a controlled amount of humidity to enter and exit.