# Will Poly Finish Yellow?



## JimiGuy7 (Jan 10, 2008)

I have heard mixed thoughts on this question so i thought I would bring it here. The reason I ask if a poly finish will yellow, is that my chum has an Orville (not Orville by Gibson) Les Paul Custom in white and he thinks it is a nitro finish, as it has yellowed. He stated, as have many other people, that poly won't yellow but nitro does. I read that Orville by Gibson was nitro and Orville, was poly. Was there maybe a time when they were using nitro on Orvilles?


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## Taylor (Oct 31, 2014)

The issue--I think-- is the vagueness of the term "Poly". POLYESTER finishes will almost never yellow to an appreciable extent, and modern water-based POLYURETHANE will almost never yellow (at least not by much), _however,_ oil-based Polyurethane (which is still hugely popular, and which was the sole polyurethane option for many years) _will_ age to an amber/yellow, though generally at a slower rate than nitrocellulose. Checking is a better gauge to determine finish than discoloration is.


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## Geetarz (Jan 19, 2016)

Very well put Taylor. I would perhaps add that "clear" Oil based PolyU tends to have a yellow/amber hue in its initial application when compared to "clear" Water based PolyU...and as Taylor has noted, will increase in darkness of tone over the years...








water-based top half, oil-based lower half


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## nnieman (Jun 19, 2013)

My 2008 fender mim baja tele has yellowed quite a bit.
If you take the pickguard off there is a noticeable difference in the colour.

It's polyester.

I used to have a squire strat mik that started out white and had yellowed as well.
Except where your forearm rested on it, that was white.

Polyester will yellow, just not as fast as other finishes.

The orville is almost definitely polyester, most Japanese guitars are/were.

http://www.mylespaul.com/forums/other-single-cuts/2299-orville-orville-gibson.html

Nathan


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## blue_dog (Feb 7, 2013)

Taylor said:


> The issue--I think-- is the vagueness of the term "Poly". POLYESTER finishes will almost never yellow to an appreciable extent, and modern water-based POLYURETHANE will almost never yellow (at least not by much), _however,_ oil-based Polyurethane (which is still hugely popular, and which was the sole polyurethane option for many years) _will_ age to an amber/yellow, though generally at a slower rate than nitrocellulose. Checking is a better gauge to determine finish than discoloration is.


Exactly like how Taylor put it.


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## Taylor (Oct 31, 2014)

Another consideration is that the clear topcoat (be it polyester, polyurethane, nitro, or what have you) only provides limited UV protection. In many cases (I've found this to be particularly true with Olympic White Fenders), there's more yellowing/ambering of the actual (pigmented) basecoat than there is of the clear topcoat.


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