Tell me about nitro finishes

HAL9000

From what I understand, most guitars come with either a nitro or poly finish. 

From what I hear nitro is thinner, ages and wears in a way that looks better than chips or dings in a poly finish, but has an unfortunate habit of reacting with lots of stuff like guitar straps, cases, stands, etc. 

On the other hand poly is thicker, tougher, doesn't react to too much, but dings look horrible (see the I've chipped my Strat thread). 

 Is that about right? Also, are there other alternatives? Or is that pretty much it?

monquixote

That's pretty much it. 

One thing to note is that some people think that all poly finishes are the half inch of glop that you get on a 70's Fender, but the reason that PRS and Suhr etc use poly is you can actually get a super thin poly finish if you know what you are doing. 

jd0272

That's pretty much IT. Lots of variations these days to both 'formulas' eg; much thinner applications available for 'poly' (generic term) finishes, but that about sums it up for me. 

But then there's stains and wudtone and oils and allsorts. Buy what suits you.

ThePrettyDamned

There are also oil type finishes, and Wudtone (not sure what this is, but I guess it's closer to an oil finish than a poly).  

strtdv

Poly- what?

Polyester is the cheaper finish, and is often associated with really thick finishes on cheaper guitars.

Polyurethane if done well is a nice thin finish and gives a good hard finish and a nice shine.

Nitro doesn't chemically change as it dries, it just loses solvent. Add the solvent again and the nitro will soften.

Polyurethane and polyester undergo a chemical reaction as they harden, and it's essentially irreversible.

Old style nitro took ages to cure fully, so now most companies using it use catalysed nitro to speed up the process. This often has the disadvantage that the nitro never really gets as hard as uncatalysed nitro and can sometimes feel sticky.

Nitro can have the issue where the chemistry of some people's sweat reacts with it and can discolour or even strip it.

No such issues with polyester or polyurethane.

ICBM

strtdv said:

Poly- what?

Polyester is the cheaper finish, and is often associated with really thick finishes on cheaper guitars.

Polyurethane if done well is a nice thin finish and gives a good hard finish and a nice shine.

This is one of my pet peeves… "poly". There is no such thing, it just seems to be used as a broad-brush ( ) put-down of anything that isn't "nitro".

Even polyester can be used well and produce a thin, hard finish as well as a nice shine.

Nitrocellulose (even there there's no such thing as "nitro" although you're unlikely to find nitrous oxide or nitroglycerine used on a guitar ) does look and feel more "natural", and it does age in a gentle, progressive way - but it has the major disadvantage of reacting to many guitar stands, straps and even clothing and some case linings, which can permanently mar it.

Given the choice I prefer non-"nitro" finishes for the last reason, although some polyurethanes can suffer from it too.

FelineGuitars

Nitro finishes on necks can fee a bit gummy and sticky and are the reason that some players claim to hate painted necks . 

Polyester on the other hand doesn't feel sticky in my experience as it's gone off too hard to feel tacky

But nitro vs Poly - I'm with ICBM on this

It is one of those many subjects bandied about the web with some people spouting hard opinion without ever really trying out all the options - just repeating what they have read