Pickup gurus...a question

[Spence]

"Explain how the finish will alter the tone on a solid body? Not some vague ideas... tell all of us how it affects the tone. That's as silly as people who say nitro allows the wood to "breathe" ... or that it allows the wood to dry out. Of course wood doesn't breathe, and if a finish can let moisture out, it will also let it in."

My Father worked for DuPont in Wilmington developing paints and lacquers from '68 to '72. I asked him about these lacquers. He told me that nitrocellulose would draw moisture out of wood while the early poly coatings would draw moisture in.
This may be why some of those early Fender poly coats would fall off in chunks with moisture getting under them.
I do believe that the thickness of lacquer on guitars makes a difference because I have seen plenty of guitars have a thick poly coat removed and a thin celly coat put on and the difference is clear. But, as Jonson will tell you, a thin poly coat will do the same trick as a thin celly coat.

[Bill M]

My Father worked for DuPont in Wilmington developing paints and lacquers from '68 to '72. I asked him about these lacquers. He told me that nitrocellulose would draw moisture out of wood while the early poly coatings would draw moisture in.
This may be why some of those early Fender poly coats would fall off in chunks with moisture getting under them.
I do believe that the thickness of lacquer on guitars makes a difference because I have seen plenty of guitars have a thick poly coat removed and a thin celly coat put on and the difference is clear. But, as Jonson will tell you, a thin poly coat will do the same trick as a thin celly coat.

Here's a 68 Paisley Tele with some big chunks coming off. It was just in the shop for a bridge pup rewind.

[Possum]

Oh Redhouse you always get things backwards, I'm used to it by now. The first thing I did when those two test guitars showed up was gut them, and rewire with all new parts. I do that to all new guitars that show up, 'cause they all have crap harnesses, been doing that for years. At least you seem to agree with me that stripping off all the finish on that Squire vastly improved the tone. Well I think you do, I have a hard time understanding you sometimes, but I think the feeling is mutual, oh well, two old geezers with brain damage? The Squire is Chinese made, the neck is basically an unfinished type, or very little finish, can't tell, its not glossy, it has the big headstock which adds some sustain I think. Yeah its a piece of crap but what I did made it into a nice player. Vintage finishes that I've seen were always very thin. I think thats a key right there. I hate that some cheapie new guitars can be pretty decent but then they glop these heavy plastic finishes on top of the wood and what could have been a great guitar just sounds like its made of glass, I have an Epiphone ES395 guitar thats wonderful but it just lacks the warmth a real one has because of the finish...

[David Schwab]

My Father worked for DuPont in Wilmington developing paints and lacquers from '68 to '72. I asked him about these lacquers. He told me that nitrocellulose would draw moisture out of wood while the early poly coatings would draw moisture in.

I don't see how that is remotely possible. I can see where a poly coat might seal the wood off, but wood will find it's equilibrium. It's hygroscopic, so once it's fully dried, it will absorb and release moisture depending on the climate.

The DuPond lacquers that Fender used are acrylic automotive lacquers. We used the same paints at American Showster since they had the vintage Chevy colors like matador red and tropical turquoise.

If finish is coming off in chunks it's because there was poor bonding. You see this if you use a soft sanding sealer and spray a hard film finish over it. But it doesn't really have to do with moisture in the wood. We would hope the wood was sufficiently kiln dried before they made a guitar out of it! If it was wet, you also wouldn't be able to sand or glue it well.

[David Schwab]

Here's one of mine...

Nice looking Tele. I like the matt finish.

Mine has a back story. I wanted to make a regular blond Tele.. you know with the white see through finish. My buddy said I might as well just buy the parts then and put one together. So I decided I'd do a carved maple top, and a set neck. And then the swamp ash body blank was too wide for my planer and I didn't feel like cutting it in half, planning and gluing it together, so I made it thick like a Les Paul and then altered the body to include a little Jazzmaster and ES-335 vibe.

So it kind of helped designed itself.

The neck is curly maple and purplehart, so it's a pretty bright, but smooth sounding guitar.

[Spence]

I don't see how that is remotely possible. I can see where a poly coat might seal the wood off, but wood will find it's equilibrium. It's hygroscopic, so once it's fully dried, it will absorb and release moisture depending on the climate.

The DuPond lacquers that Fender used are acrylic automotive lacquers. We used the same paints at American Showster since they had the vintage Chevy colors like matador red and tropical turquoise.

If finish is coming off in chunks it's because there was poor bonding. You see this if you use a soft sanding sealer and spray a hard film finish over it. But it doesn't really have to do with moisture in the wood. We would hope the wood was sufficiently kiln dried before they made a guitar out of it! If it was wet, you also wouldn't be able to sand or glue it well.

My old Dad? What would he know? Well, when you get a chance, have a read of this http://article.pubs.nrc-cnrc.gc.ca/R...pf=v75-154.pdf
Research like this is why DuPont snapped him up.
My old Dad is a pretty high brow chemist, not some assembly guy in a guitar factory.

[Dave Kerr]

This has to be some kind of record for me, getting through so little of a piece of literature that makes such frequent reference to cleavage.

[RedHouse]

Oh Redhouse you always get things backwards...

Naa, just stroll through your posts on this forum, it's all here, I don't have it backwards. Are ya related to Jon Lovitz by chance?

...at least you seem to agree with me that stripping off all the finish on that Squire vastly improved the tone...

Again, naa.

Scroll back up a few posts and clearly read my post which doesn't agree with you on that. I found very little change w/o the finish and certainly not enough to warrant removing the finish on a $199 guitar.

A chinese Strat is not simply an American Strat stranded in a low-price-point body waiting to get out by replacing the wiring harness and removing the finish.

..two old geezers with brain damage?...

Well old yes, but...

...(sounds of crickets chirping)...

[David Schwab]

My old Dad? What would he know? Well, when you get a chance, have a read of this http://article.pubs.nrc-cnrc.gc.ca/R...pf=v75-154.pdf
Research like this is why DuPont snapped him up.
My old Dad is a pretty high brow chemist, not some assembly guy in a guitar factory.

That's fine, but that paper has nothing to do with a finish "drawing moisture" in or out of wood.

If you read up on acoustic guitar building, or any wood working, you will see that when you finish one side of a piece of wood, you should do the other. Otherwise the unfinished side will absorb more moisture and will expand and cup the board. It doesn't mater what kind of finish it is.

It would be easy enough to test for yourself with some thick veneer and various finishes.

This is standard wood working knowledge.

Ben Plewes says in “How does Wood Work?” from Good Woodworking Magazine:

There is a general misconception that once wood has been seasoned you don’t need to worry about its moisture content anymore. If only life were that straightforward! Wood continues to expand and contract after the initial drying process is complete. In fact wood, even with a synthetic finish applied, will continually adapt to the ambient moisture level that surrounds it. It’s a slow process so you’re not going to see your wood move the minute you open a window but it will move over a period of weeks to match the average conditions around it.

And that's why you have to readjust your truss rod when the seasons change.

Probably some useful info in here:

http://www.fpl.fs.fed.us/documnts/fplrp/fplrp462.pdf

[RedHouse]

...Otherwise the unfinished side will absorb more moisture and will expand and cup the board. It doesn't mater what kind of finish it is...

As that quote said, even completely finished wood will expand/contract with humidity and temperature.

My uncle was a cabinet/furnature maker he once showed me a set of endtables he made that had glass inlaid in the tops with about a 1" border as the table edge, pane glass recessed flush with the top of the wood.

The glass was shattered and I asked him what happened thinking it was damaged in shipping, he said it was an experiment to see just how snug a fit a tables glass top could be embeded without a problem, then explained to me how wood expanded/contracted. I was an instant believer.

[David Schwab]

As that quote said, even completely finished wood will expand/contract with humidity and temperature.

My uncle was a cabinet/furnature maker he once showed me a set of endtables he made that had glass inlaid in the tops with about a 1" border as the table edge, pane glass recessed flush with the top of the wood.

The glass was shattered and I asked him what happened thinking it was damaged in shipping, he said it was an experiment to see just how snug a fit a tables glass top could be embeded without a problem, then explained to me how wood expanded/contracted. I was an instant believer.

Yes, when you design furniture, you must allow panels to move and for wood expansion on large surfaces. So things like drawer bottoms and panels in cabinet doors shouldn't be glued in the frame.

It's a wonder guitars stay together!

[Amit]

So if the finish on solid body guitars has nothing to do with "deep" wood moisture content, and it's there just for looks, then if I don't care about looks, can I build my guitars with swamp ash/alder etc and leave them without finish at all?
What about necks? can they be left totally unfinished no matter the type of wood and still behave well?
Regarding maple necks, at least with Warmoth, I remember they say they will warrant only sealed finished maple necks... why?

[Mike Sulzer]

What about necks? can they be left totally unfinished no matter the type of wood and still behave well?
Regarding maple necks, at least with Warmoth, I remember they say they will warrant only sealed finished maple necks... why?

I would believe Warmoth. The finish slows down the penetration of moisture so that the content is set by the average environment, and so sudden changes from a wet hand to not happen. Some kinds of wood have enough natural oil to do this without a finish.

[RedHouse]

So if the finish on solid body guitars has nothing to do with "deep" wood moisture content, and it's there just for looks, then if I don't care about looks, can I build my guitars with swamp ash/alder etc and leave them without finish at all?
What about necks? can they be left totally unfinished no matter the type of wood and still behave well?
Regarding maple necks, at least with Warmoth, I remember they say they will warrant only sealed finished maple necks... why?

Yep, that's Warmoth's gaurantee, they are a good company as far as woodwork, but they kinda suck with some of their policy's.

Alternatively there's Carvin who backs-up their necks with only a thin coat of sealer or toung-oil and have been around way longer than Warmoth. They would know by now is a neck required a complete finish to gaurantee it.

[David Schwab]

I would believe Warmoth. The finish slows down the penetration of moisture so that the content is set by the average environment, and so sudden changes from a wet hand to not happen. Some kinds of wood have enough natural oil to do this without a finish.

Yes, and maple and similar woods will get very dirty, and softer woods like pumpkin (swamp) ash might start to deteriorate over time.