Simple question, and i'm sure its been covered before. But what do you use for the final clear coat and why?

is one better than the other?
better protection?
better looking?
does it make a difference?

Lacquer is the better choice in my book. Poly is nearly indestructible, so it offers the best protection, but you are entombing the wood in plastic, so it will barely age, if at all, simply because it cannot release moisture.

Lacquer is easy to work with, though it is highly flammable and volatile, plus it looks best, is repairable and easier to clean out of your spray gun. Just make sure you use a quality lacquer like McFadden or Sherwin-Williams.

Sorry if this is totally off base but I'm selling a guitar that "should" have a nitrocellulose finish. I keep getting questions about this. Why would this be a good thing? Is there a way to tell for sure if it is?

Thanks

Lacquer is the better choice in my book. Poly is nearly indestructible, so it offers the best protection, but you are entombing the wood in plastic, so it will barely age, if at all, simply because it cannot release moisture.


Why do you want the wood to age? Also, why wouldn't the builder have ensured that the wood had a suitable moisture content prior to building the instrument?

Sorry if this is totally off base but I'm selling a guitar that "should" have a nitrocellulose finish. I keep getting questions about this. Why would this be a good thing? Is there a way to tell for sure if it is?

Thanks

I've met people who think that a nitro finish sounds better than other finishes. How old is the guitar that you're selling? You could look for checking/crazing and yellowing of the finish which can indicate that it is a nitrocellulose lacquer finish, but it isn't definitive either way.

Personally, my body chemistry is such that I stick to Nitro, and it gets gummy. I hate it. For that reason, I like Poly better. Some claim that Nitro sounds better. I can't hear it. YMMV.

Personally, my body chemistry is such that I stick to Nitro, and it gets gummy. I hate it. For that reason, I like Poly better. Some claim that Nitro sounds better. I can't hear it. YMMV.

Yeah, me too! I keep several coats of a really good wax on the body and neck of the bass to keep that from happening. I'll probably reach the point where I have too much wax on it, but until then - ya gotta do what ya gotta do!

Dan K.

Yeah, me too! I keep several coats of a really good wax on the body and neck of the bass to keep that from happening. I'll probably reach the point where I have too much wax on it, but until then - ya gotta do what ya gotta do!

Dan K.

Lacquer is easier to repair usually. A new coat will melt and bond well to old layers Poly is tough to repair and often needs to be sanded down to bare wood and refinished.

However, poly is much more moisture resistant and chemical resistant an d stands up to wear better. Nitro lacquer will be damaged easily by alcohol and other chemicals.

In a solid body instrument you won't hear any difference in sound between the finishes. An acoustic guitar or violin-yes.

Personally, I prefer the look of nitro lacquer over poly.

Why do you want the wood to age? Also, why wouldn't the builder have ensured that the wood had a suitable moisture content prior to building the instrument?

So are you saying that once you have a suitable moisture content, it's OK to seal the wood in plastic?

Instruments finished in lacquer age well for a reason. Moisture can escape, letting the wood dry out more, creating more air space in the wood cells which equals more resonance.

As far as sticking to lacquer finishes, that is usually only a problem when too much retarder was added when the lacquer was shot, rendering the finish softer than normal. Unfortunately, there is no way to know this.

FYI- Fender "lacquer" finishes du jour are nitro over a poly base.

Instruments finished in lacquer age well for a reason. Moisture can escape, letting the wood dry out more, creating more air space in the wood cells which equals more resonance.

I'd love to see the scientific documents where you found that one. Should be an interesting read... if it can be found.

I shoot poly because of the trouble involved in shooting Lacquer in the high humidity of central Florida...t

I love the look of worn spots where and instrument is played. I admire relicing but don't really want to invest in doing that myself if I can wear one out myself or buy one that's been played hard. Laquer for me please.

so what im gettin out of this is laquer will age and wear and poly will stay fresh and new

so what im gettin out of this is laquer will age and wear and poly will stay fresh and new

Sort of. Lacquer will wear faster than poly. If you're trying to decide on a finish you can apply yourself and you have no experience, then Poly is probably your best choice. There's still lots to learn to apply poly and even simple Minwax Wipe On Poly has certain do's and don'ts to get an acceptable result.

The original post asked about what was better for a FINAL coat and that hasn't been covered.

Bear in mind that not all finishes are compatible with each other. So you can't just go and spray lacquer over a thick poly finish and expect good results. It's usually best to stick within one group of products from the first coat to the last.

So are you saying that once you have a suitable moisture content, it's OK to seal the wood in plastic?

Yes, why wouldn't it be?

Instruments finished in lacquer age well for a reason. Moisture can escape, letting the wood dry out more, creating more air space in the wood cells which equals more resonance.


Why would the wood necessarily dry out more? If the wood can breathe through the finish then it is going to gain/lose moisture depending on the humidity.

There's a lot of inacurate information in this thread.

fyi, as far as sealing the wood goes, lacquer and poly will do exactly the same thing. lacquer will not let more moisture out of the wood than poly.

lacquer will age just as poly will age. poly does not stay 'fresher' than lacquer, it just wears less because it is more solid.

adding more retarder does not render the finish 'softer', it'll just take longer to cure and more solvents will evaporate leaving a THINNER finish that should require more coats than if no retarder was used.

of course, I am not an expert on finishing, but a quick browse through any decent wood finishes book will clear this stuff up. I consulted 'Understanding wood finishes' by bob flexner.

There's a lot of inacurate information in this thread.

fyi, as far as sealing the wood goes, lacquer and poly will do exactly the same thing. lacquer will not let more moisture out of the wood than poly.

lacquer will age just as poly will age. poly does not stay 'fresher' than lacquer, it just wears less because it is more solid.

adding more retarder does not render the finish 'softer', it'll just take longer to cure and more solvents will evaporate leaving a THINNER finish that should require more coats than if no retarder was used.

of course, I am not an expert on finishing, but a quick browse through any decent wood finishes book will clear this stuff up. I consulted 'Understanding wood finishes' by bob flexner.


+1 on every single point in this post. Including consulting the Flexner book, that's one of the great books in my ever growing builder's bookshelf, soon to be two book shelves at the rate I'm buying them.

+1 on every single point in this post. Including consulting the Flexner book, that's one of the great books in my ever growing builder's bookshelf, soon to be two book shelves at the rate I'm buying them.

I agree. Flexner's book is a good one. I also like the books by Jeff Jewitt. His "Hand Applied Finishes" is great for some basic finishes that can be done without spray equipment.

There's a lot of inaccurate statements made about finishing all the time, same as there is about amps and speakers. Most of it gets started by someone who doesn't know and then gets repeated and altered each time it's repeated and people start accepting it as truth.

It's best to start with one of the good books mentioned and try a simple finish out for yourself. With practice your skills develop and you can then go on to tougher methods.

I've seldom heard as much misinformation passed along as gospel as I have when the topic is finishing; it's one of the subjects our students have the greatest difficulty understanding, much less mastering.

Flexner & Jewitt are both excellent resources. Jewitt's website is very informative as well:

www.homesteadfinishing.com

Also +1 to Geoff's statements: a piece of wood eventually reaches an equilibrium moisture content (EMC). That is, it loses or gains moisture to or from the atmosphere, until the "forces" (actually partial vapor pressures) causing it to lose moisture to the air equal the "forces" causing it to gain moisture from the air.

At this point, if the atmospheric humidity remained the same, the wood would also remain at a constant moisture content. In reality, of course, atmospheric humidity goes up and down, and so the wood's moisture content tracks this change, up or down, until it reaches a new equilibrium.

The thickness and type of the finish will change the rate at which the wood tracks the atmosphere, but it doesn't change the final value of moisture content.

Also +1 to Geoff's statements: a piece of wood eventually reaches an equilibrium moisture content (EMC). That is, it loses or gains moisture to or from the atmosphere, until the "forces" (actually partial vapor pressures) causing it to lose moisture to the air equal the "forces" causing it to gain moisture from the air.

At this point, if the atmospheric humidity remained the same, the wood would also remain at a constant moisture content. In reality, of course, atmospheric humidity goes up and down, and so the wood's moisture content tracks this change, up or down, until it reaches a new equilibrium.

The thickness and type of the finish will change the rate at which the wood tracks the atmosphere, but it doesn't change the final value of moisture content.

+10! Very well said, sir! I'll bet you got an A+ in wood technology, didn't you :D

I'm not being smug people, but my 30+ years of experience tells me that I am correct on this. And I am far from being alone, having spoken with MANY other small builders AND large companies over the years.

Poly, in the long run, is easier and cheaper to work with, yet most fine instrument makers continue to use nitro. REAL nitro, not the catalyzed crap. There are reasons for that.

Look, I won't argue this all day, but consider this: it is not possible for wood to be continually losing moisure over its life, because to do so it would have to start out with an infinite supply.

The equilibrium-seeking description I put forth previously also applies to many things beyond wood. Liquid diffusion, vapor balances, even distribution of dissolved doping agents in multiphase metal alloys.



And all this is beyond the idea that if someone is looking to get that amazing sound that e.g. James Jamerson got, you don't want a fantastic 50-year-old-aged-wood Fender, because he was playing a new Fender made from trees cut only a year or two before.

I'm not being smug people, but my 30+ years of experience tells me that I am correct on this. And I am far from being alone, having spoken with MANY other small builders AND large companies over the years.

Poly, in the long run, is easier and cheaper to work with, yet most fine instrument makers continue to use nitro. REAL nitro, not the catalyzed crap. There are reasons for that.


It would be very helpful if you could offer a few citations from credible sources to support your statements.

One of the key reasons nictrocellulose lacquer has been such a popular commercial finish for so many years is its economic advantages (it dries quickly), not because it is a superior finish.

Many of the new students who enroll in our wood technology and finishing classes hold some of the same kinds of "beliefs" when they start - fervently held opinions usually based upon misunderstanding, incomplete information, hearsay, misinformation, and marketing hyperbole. After a few years, most of them are able to extrapolate what they've learned to willingly deconstruct their previously held beliefs.

The fact that something has been believed and/or repeated for a number of years, or by a large number of people, doesn't make it true. Opinions unsupported by facts and reasoning are seldom compelling - no matter how fervently believed or forcefully expressed.

Also +1 to Geoff's statements: a piece of wood eventually reaches an equilibrium moisture content (EMC). That is, it loses or gains moisture to or from the atmosphere, until the "forces" (actually partial vapor pressures) causing it to lose moisture to the air equal the "forces" causing it to gain moisture from the air.

At this point, if the atmospheric humidity remained the same, the wood would also remain at a constant moisture content. In reality, of course, atmospheric humidity goes up and down, and so the wood's moisture content tracks this change, up or down, until it reaches a new equilibrium.

The thickness and type of the finish will change the rate at which the wood tracks the atmosphere, but it doesn't change the final value of moisture content.

OK, fine. Go ahead and ruin a good argument with pure logic and physics!

I always thought a white bass sounded brighter than a black bass, and a brown one sounded muddy.

Which then, would be the finish that least inhibits resonance of the wood? :confused:

Which then, would be the finish that least inhibits resonance of the wood? :confused:

there is no such thing as a finish that inhibits resonance of a solid body instrument.

Laughing at this thread.:hiding:

there is no such thing as a finish that inhibits resonance of a solid body instrument.

How is it that people say that there is a difference in how certain finishes " sound" .
If the finish would not do anything, those dicussions woudn't arise, would they? ;)

How is it that people say that there is a difference in how certain finishes " sound" .
If the finish would not do anything, those dicussions woudn't arise, would they? ;)

because their talking out of their butts.

Today 12:27 PM
wilser
Quote:
Originally Posted by cnltb View Post
How is it that people say that there is a difference in how certain finishes " sound" .
If the finish would not do anything, those dicussions woudn't arise, would they?

because their talking out of their butts.

I love this thread :hyper:

Personally, I like lacquer. It's easy and fast to apply and relatively easy to repair. This may be due to the fact that I've never tried to spray poly, only brush applied, and w/o a very clean environment the dust will settle into poly before it dries - then what do ya do?

I have used both poly and lacquer, both with decent results. My opinion - lacquer is an easier finish to get right, because the coats flow together, and you won't get witness lines from sanding through one layer into the next.

That being said, it also takes a lot longer to cure than poly, is *much* more dangerous to work with (super flammable and very hard on the lungs).

I don't know about the chemical properties of poly or nitro, or whether wood needs to breathe or not, but i do know this -

Fender was well known for building guitars using the most efficient processes possible (read:cheapest). All this talk about nitro being a very hard finish to use, and how it makes vintage guitars sound so good, sounds like nonsense to me. I'm not saying nitro is easy to apply, but I bet if there was a easier finish to apply then, Fender would have used it.

why then oil finish does not sound like poly finish? =/
(or it sounds same? :D)

As a matter of fact oil finishes should "breathe" the most as the instrument is not encased in anything. So according to the above mentionned logic, oil finishes should sound the best.

If that was the case the majority of finishes out there would be oil finishes, wouldn't they since everyone wants their instruments to sound the best. Which is not the case at all.

As a matter of fact oil finishes should "breathe" the most as the instrument is not encased in anything. So according to the above mentionned logic, oil finishes should sound the best.

If that was the case the majority of finishes out there would be oil finishes, wouldn't they since everyone wants their instruments to sound the best. Which is not the case at all.

But wait a minute ...advocates of oil often say the mantra "oil penetrates the fibers hardening within the wood and protecting it from the inside out" ...WTF?!?!?

It can't harden it that much since you'll still dent the bass a lot easier with an oil finish than lacquer or poly finish. :D

Apples and oranges guys. I have a 24 year old shotgun with a oil finish that looks brand new and I'm not easy on my equipment. (rain and snow)

It can't harden it that much since you'll still dent the bass a lot easier with an oil finish than lacquer or poly finish. :D

hey, I'm with you buddy ...I'm just saying what 'they' say ;)

Apples and oranges guys. I have a 24 year old shotgun with a oil finish that looks brand new and I'm not easy on my equipment. (rain and snow)

Apples and apples if it's the same 'tru-oil' type of finish they use on guitars a lot.

Apples and apples if it's the same 'tru-oil' type of finish they use on guitars a lot.

Although I am a true believer in tru-oil I was referring to a raw linseed oil soak and a double boiled hand rubbed top coat.:)

As a matter of fact oil finishes should "breathe" the most as the instrument is not encased in anything. So according to the above mentionned logic, oil finishes should sound the best.

If that was the case the majority of finishes out there would be oil finishes, wouldn't they since everyone wants their instruments to sound the best. Which is not the case at all.

A good quality hand rubbed oil finish takes about 60 days plus/minus. I don't think mass production blends well with this equation. usually good quality oil finishes come from custom builders.
Not lookin to argue just saying what I feel. :)

because their talking out of their butts.

Not saying anyone's right or wrong because I know just about zilch on this topic, but isn't the finish suspected of being the big reason why Stradivarius violins and cellos sound so great? Everything else can be duplicated (and has been duplicated), but no one's sure about the formula for the varnish he used.

Edit: and just to add to the conversation, my shipment of reranch nitro cans came yesterday. :)

Mofo, Violins are hollowbody instruments, that makes a big diference :)

Does it? How?

Does it? How?

The tops on hollow-bodies are actually thin enough to vibrate, changing the sound character.

Stradivarius used some sort of bianca (egg white, gum arabic, honey) to finish his instruments. Not sure how it holds up in a gigging environment.

And by the way, somone has found something about strad violins. Apparently the wood he used was soaked in... something... that this guy believes is sea water. If you do a google, you will find that he has already built a violin that has trumped a strad in a double blind test.

Got a link?

Got a link?
Interview with the Professor of Biophysics and Biochemistry (http://charmian.sonoma.edu/~bryant/Fall2006/Phys300%20F06/Phys300%20info%20by%20chapter/violins/Scientific%20American%20Secrets%20of%20the%20Strad ivarius%20An%20Interview%20with%20Joseph%20Nagyvar y.htm)
A paper he wrote (http://www.rsc.org/Education/EiC/issues/2005July/violins.asp)

I cant find the site where i read that his violins won (by a bit), but im sure a 50% error rate in a double blind is enough to say that he's got something going.

Well, after 10 years of all poly or oiled basses, I just got an alleva-coppolo finished in nitro. The super thin finish looks amazing because all you see is the color and it's not like you are looking through a centimeter of plastic wrap, then the color, then the wood.
I really love the nitro look, although I find nitro necks to be a little "grabbier" than oil/waxed ones.

check out the club ac thread if you want to see pics.

Well, after 10 years of all poly or oiled basses, I just got an alleva-coppolo finished in nitro. The super thin finish looks amazing because all you see is the color and it's not like you are looking through a centimeter of plastic wrap, then the color, then the wood.
I really love the nitro look, although I find nitro necks to be a little "grabbier" than oil/waxed ones.

check out the club ac thread if you want to see pics.

Happy for you! Good think you didn't start speculating on how it "sounds better" because the thinner finish "let's the wood breathe" :bawl:

re: strad...

Another factor is that the build years for those instruments had been preceded in the previous on or two hundred years by a "little ice age," resulting in trees with tighter ring spacing than could ever be reproduced (according to other "experts").

re: strad...

Another factor is that the build years for those instruments had been preceded in the previous on or two hundred years by a "little ice age," resulting in trees with tighter ring spacing than could ever be reproduced (according to other "experts").

Yeah i heard that too... One thing in favour of this guy is that he has built violins too.

Well, After spending the last hour searching the forum for "witness lines" I decided that I would seek out help on this thread (instead of starting a new one).

I've read a lot of posts about witness lines but no one ever says that you can diminish them by... or if you coat over the whole surface they will not be as visible...

If I were to be blunt and my assessments are correct, is the statement below true or not true?

"WITNESS LINES! You are Screwed! There is no way to get rid of them short of removing the whole finish and starting over!"

Would love to hear from some Poly Expert!

(My apologies if I am taking over the thread but I do think it's part of the topic. )

Nomad, do you have a pic and details about what product you're using?

I'm at work so no picts right now but:

It's my second bass build and I decided to layer on Minwax Semi Gloss over my lacquer (I ran out and it was getting to cold to spray Nitro).

I was brushing on multiple coats and not being super concerned about sanding between coats. Figured I would do one great poly sand after I knew there would be enough poly so I wouldn't break through. I know I haven't broken through the poly to the lacquer but there are faint lines now where I have sanded the poly, that follow the high and low spots that I sanded flat. Like contour lines one a map that show elevation!

That's my description, I hope it makes sense.

I ran into the term "witness lines" after I had committed to this process so I am prepared for the "tough love" lecture, so to speak...

hmmm, strange. Usually witness lines come from coats that didn't burn into each other (be it because it cured too long between coats or contamination). I am not familiar with the characteristics of minwax burn in window, but is it possible you waited too long between coats? I have only used minwax' wipe on poly product and those films don't get thick enough for witness lines.

I'm at work so no picts right now but:

It's my second bass build and I decided to layer on Minwax Semi Gloss over my lacquer (I ran out and it was getting to cold to spray Nitro).

I was brushing on multiple coats and not being super concerned about sanding between coats. Figured I would do one great poly sand after I knew there would be enough poly so I wouldn't break through. I know I haven't broken through the poly to the lacquer but there are faint lines now where I have sanded the poly, that follow the high and low spots that I sanded flat. Like contour lines one a map that show elevation!

That's my description, I hope it makes sense.

I ran into the term "witness lines" after I had committed to this process so I am prepared for the "tough love" lecture, so to speak...

Well I think that some coats cured between application of the next. When I sanded it was like there were fine dark lines that follow the contours of the raised sanded areas that are now flat. They do buff out a little but I will have to post a picture.

Thanks for responding Wilser!

I'm at work so no picts right now but:

It's my second bass build and I decided to layer on Minwax Semi Gloss over my lacquer (I ran out and it was getting to cold to spray Nitro).

I was brushing on multiple coats and not being super concerned about sanding between coats. Figured I would do one great poly sand after I knew there would be enough poly so I wouldn't break through. I know I haven't broken through the poly to the lacquer but there are faint lines now where I have sanded the poly, that follow the high and low spots that I sanded flat. Like contour lines one a map that show elevation!

That's my description, I hope it makes sense.

I ran into the term "witness lines" after I had committed to this process so I am prepared for the "tough love" lecture, so to speak...

Yes, that sounds like "witness lines" to me and are caused when you sand through one layer of varnish and into the previous one. It happens with finishes which don't partially dissolve the previous coat, such as varnish which polyurethane is. You don't get this problem with lacquer or shellac and some other catalyzed finishes which partially dissolve the previous coat, but it's common with varnishes. The only thing to do to avoid it is to be very careful to not sand through the final coat to the previous one. The final coat should be sufficiently thick to allow sanding and level enough to not require a lot of sanding to level out application marks, drips, runs, etc. You should do all the leveling before applying the final coat, and make your final coat as flawless as possible.

This is easier said than done, I know. It's very tough also with wipe on finishes such as Minwax Wipe On Poly which are applied quite thin by nature. And you can't flow these on very thick without them running or dripping. It takes about 3 wiped on coats of one of these products to equal the thickness of one brushed on coat of regular polyurethane or alkyd varnish.

Brushing on the last coat of varnish using full strength varnish (not the thinned out wipe on varnishes) is one way to get a thick enough final coat. But you need a very good brush and practice with one to get it right. That's why those wipe on finishes are so popular. They're easy for an amateur to apply without a lot of experience or expensive brushes and still get an acceptable result. Of course, that "acceptable" result isn't really acceptable if you want a flawless, mirror piano shine on your instrument or furniture.

What you can do is sand what you have to a very level surface free of any application marks and defects using 600 grit wet or dry paper using water as a lubricant. You'll have witness lines for sure. Clean up all the slurry from the sanding. Then buy a small can of regular full strength varnish from the same maker as the wipe on you used and apply as perfect coat as possible using a very good quality brush. Give it plenty of time to cure. I wait 3 weeks usually. Then start rubbing out with 600 git wet and dry with water or mineral oil as a lubricant and working up to 1000 and then 1500 grit. You really have to be careful not to sand through that final coat to avoid witness lines. If you do, you'll have to apply another coat and do it again. And wipe of all the slurry from one grit before going to a finer grit or you could have little bits of the previous grit scratch the surface. Then polish out with an automotive polishing product. It's tough to do it right. It's much easier on flat furniture surfaces such as tabletops.

Your other alternative would be to level out the final coat with very fine wet and dry paper and then go over the whole body with 0000 steel wool using thinned paste wax as a lubricant. The buff it up with a soft cotton polishing cloth. This will be more of a satin finish but will still look very good and you shouldn't see any witness lines.

One other alternative is to perfectly level what you have and then apply one perfect wipe on coat and not polish it out. You might luck out and get a very good finish that'll pass inspection from a foot away. But you'll have to make sure you apply it in a dust free environment, or at least dust free until that coat dries.

I've spent years working with varnish on furniture and a few instruments. It's a beautiful finish but it does have its drawbacks. That's one reason why sprayed on nitro cellulose finishes are so favoured on nice instruments.

But using regular consumer grade products does put you at a disadvantage. I prefer to not use polyurethane if I want a high gloss rubbed out shine. Instead I use a regular alkyd varnish with a lower amount of oil in its makeup, such as Waterlox Original Finish in gloss. Behlens Rockhard Tabletop Varnish is another good one. They'll dry very hard and will polish out to a mirror shine. But you won't find them at Home Depot, at least not around here. It's just hard to get it right and requires practice, a very good brush and a dust free and warm enough environment to apply it. The old masters managed to do it, so it can be done. I don't consider myself an old master by any means, but I'm getting better at it. But it still can be frustrating work.

Anyhow, there are entire books devoted to the subject if you really want to get into it. Bob Flexnor's and Jeff Jewitt's books are particularly good.

62bass, Thanks so much for taking the time to share that info! I believe I do have witness lines and your reply gives me some direction of attack.

Sincerely,
Nomad98

62bass, Thanks so much for taking the time to share that info! I believe I do have witness lines and your reply gives me some direction of attack.

Sincerely,
Nomad98

Great. I hope you can come up with a fix. I've managed to salvage a few pieces that I thought would never make it.

AS FAR AS I KNOW, WHEN TIMBER LOSES MOISTURE (TO EQUAL THE SURROUNDING ATMOSPHERIC MOISTURE CONTENT), IT SHRINKS. IT DOESN'T SUCK IN AIR OTHERWISE IT WOULDN'T GET SMALLER.
ANYWAY, MY QUESTION IS- WHAT'S THE BEST DURABLE NON-STICK CLEAR FINISH?

So are you saying that once you have a suitable moisture content, it's OK to seal the wood in plastic?

Instruments finished in lacquer age well for a reason. Moisture can escape, letting the wood dry out more, creating more air space in the wood cells which equals more resonance.

If lacquer can let moisture out, don't you think it will also let moisture in?

First, no one builds with wet wood. It's all been kiln dried, and it's as dry as it's going to get. Once wood is at it's equilibrium it wont get any dryer. Not all wood has air spaces.. and some are filled with oils and resins. The wood with more airspace is lighter in weight to begin with, such as light weight "swamp" ash. Wood will not get lighter as it ages, which is what you are implying.

Also I'm not convinced that nitro "breathes" any more than poly. Nitro is a plastic after all. I have 15 year old basses finished in catalyzed nito. That finish does not let moisture through, and the wood has "aged" just fine. The basses sound better now than when they were new, and it has nothing to do with moisture... the more you play them, the better they sound.

If lacquer can let moisture out, don't you think it will also let moisture in?

First, no one builds with wet wood. It's all been kiln dried, and it's as dry as it's going to get. Once wood is at it's equilibrium it wont get any dryer. Not all wood has air spaces.. and some are filled with oils and resins. The wood with more airspace is lighter in weight to begin with, such as light weight "swamp" ash. Wood will not get lighter as it ages, which is what you are implying.

Also I'm not convinced that nitro "breathes" any more than poly. Nitro is a plastic after all. I have 15 year old basses finished in catalyzed nito. That finish does not let moisture through, and the wood has "aged" just fine. The basses sound better now than when they were new, and it has nothing to do with moisture... the more you play them, the better they sound.

You have to use the special ionization process that aligns the molecules to only allow moisture to escape but not return. It creates a one-way path that prohibits all oxygen, including those bound with hydrogen from re-entering wood.



In light of some of the previous responses, I must state that I am just kidding. :cool:

If lacquer can let moisture out, don't you think it will also let moisture in?

First, no one builds with wet wood. It's all been kiln dried, and it's as dry as it's going to get. Once wood is at it's equilibrium it wont get any dryer. Not all wood has air spaces.. and some are filled with oils and resins. The wood with more airspace is lighter in weight to begin with, such as light weight "swamp" ash. Wood will not get lighter as it ages, which is what you are implying.

Also I'm not convinced that nitro "breathes" any more than poly. Nitro is a plastic after all. I have 15 year old basses finished in catalyzed nito. That finish does not let moisture through, and the wood has "aged" just fine. The basses sound better now than when they were new, and it has nothing to do with moisture... the more you play them, the better they sound.

Not to pick nits, but EMC isn't absolute or static; EMC is relative to environmental temperature and humidity, which change continually over time.

When I kiln dry a 4,000bf load of hardwood to 6%, it will reach EMC relative to the interior of the kiln during the conditioning cycle, and will reach EMC with the wood barn after it has been unstickered and stored. Here in San Diego, EMC is typically between 6% and 12%, but is typically far higher in places with higher ambient humidity levels.

When a piece of finished wood is taken from one environment to another, it will continue to respond to changes in both temperature and humidity; several coats of finish will retard the process, but will not stop it entirely.

A bass built in a relatively humid environment may stabilize at an EMC of 15%. If, after finishing, it is shipped to a relatively dry environment where EMC is closer to 6%, its EMC will decrease given sufficient time.

Not to pick nits, but EMC isn't absolute or static; EMC is relative to environmental temperature and humidity, which change continually over time.

When I kiln dry a 4,000bf load of hardwood to 6%, it will reach EMC relative to the interior of the kiln during the conditioning cycle, and will reach EMC with the wood barn after it has been unstickered and stored. Here in San Diego, EMC is typically between 6% and 12%, but is typically far higher in places with higher ambient humidity levels.

When a piece of finished wood is taken from one environment to another, it will continue to respond to changes in both temperature and humidity; several coats of finish will retard the process, but will not stop it entirely.

A bass built in a relatively humid environment may stabilize at an EMC of 15%. If, after finishing, it is shipped to a relatively dry environment where EMC is closer to 6%, its EMC will decrease given sufficient time.

You're right, of course. He wasn't talking that the wood could not change moisture content once it was dry though, but that the wood would not be able to continuously lose moisture because there is something called the EMC and basses are built with wood near the EMC. Even if the EMC point moves, the wood's not going to lose moisture (permanently, anyhow)

I've got a great idea. Why don't someone put this to rest by finishing a block of sodium (or other water reactive metal) with nitro and then pouring water on it? My hypothesis is that the sodium will NOT react, cos the nitro will not let the water through.

Oh and btw, in light of the arguments made in this thread, the best finish, is, NO FINISH. Why do we finish instruments again?

because a finish protects the wood from the elements. One of my recent customers specifically requested a thick poly finish because his previous custom (oil finished bass) was turning green (maple) from his sweat on the fingerboard pickup covers and ramp areas.

You're right, of course. He wasn't talking that the wood could not change moisture content once it was dry though, but that the wood would not be able to continuously lose moisture because there is something called the EMC and basses are built with wood near the EMC.

I've got a great idea. Why don't someone put this to rest by finishing a block of sodium (or other water reactive metal) with nitro and then pouring water on it? My hypothesis is that the sodium will NOT react, cos the nitro will not let the water through.

Oh and btw, in light of the arguments made in this thread, the best finish, is, NO FINISH. Why do we finish instruments again?

because a finish protects the wood from the elements. One of my recent customers specifically requested a thick poly finish because his previous custom (oil finished bass) was turning green (maple) from his sweat on the fingerboard pickup covers and ramp areas.

hrmmm. but there are woods that don't need finishing, right? like wenge and stuff like that...? we could build basses out of only oily woods!

I've got a great idea. Why don't someone put this to rest by finishing a block of sodium (or other water reactive metal) with nitro and then pouring water on it? My hypothesis is that the sodium will NOT react, cos the nitro will not let the water through.


How about putting a bass in a hypobaric chamber and seeing if it explodes! Now we're talking fun!

Also, the finish slows down the response to ambient conditions, so the instrument can be more constant over time. E.g., consider: if it were manufactured at 9% MC; if a permanent summer humidity level would result in a 12% EMC; and if a permanent winter humidity level would result in a 6% EMC. But it the finish slows down the MC change, and if you receive the instrument in the mid-summer, the MC is being driven towards 12%, but maybe it only reaches 10% by the end of the summer; and then winter kicks in, the MC is being driven towards 12%, and again the finish slows things down, so it only reaches 8% MC by the end of winter; etc. So with a moisture-insulating finish, you can potentially have a more dimensionally stable instrument.

hrmmm. but there are woods that don't need finishing, right? like wenge and stuff like that...? we could build basses out of only oily woods!

they don't "need" finishes in the sense that they won't react the same as other types of wood, but they will just the same get grimey and ugly.

Not to pick nits, but EMC isn't absolute or static; EMC is relative to environmental temperature and humidity, which change continually over time.

When I kiln dry a 4,000bf load of hardwood to 6%, it will reach EMC relative to the interior of the kiln during the conditioning cycle, and will reach EMC with the wood barn after it has been unstickered and stored. Here in San Diego, EMC is typically between 6% and 12%, but is typically far higher in places with higher ambient humidity levels.

When a piece of finished wood is taken from one environment to another, it will continue to respond to changes in both temperature and humidity; several coats of finish will retard the process, but will not stop it entirely.

A bass built in a relatively humid environment may stabilize at an EMC of 15%. If, after finishing, it is shipped to a relatively dry environment where EMC is closer to 6%, its EMC will decrease given sufficient time.

Yes, of course. But that wasn't what I meant. The post I was replying to made the assumption that wood would continue to dry out until it was bone dry.

I do realize that wood will continue to gain and loose moisture content, even if it stays in one location (assuming it's temperate).

We have all seen fretboards shrinking and exposing the fret ends, and necks that need tweaking.

So I was over simplifying a bit.

I've got a great idea. Why don't someone put this to rest by finishing a block of sodium (or other water reactive metal) with nitro and then pouring water on it? My hypothesis is that the sodium will NOT react, cos the nitro will not let the water through.

OK, but you go first! :eek:

has anybody mentioned Young's Modulus yet? check it out and you'll see why the the best necks are 1/4 sawn maple. the finish is irrelevant to the sound (solid bodies), it just protects from stains. timber is a good, strong, build material, natural fibre reinforced technology. it has limitations, it's hygroscopic so it moves but it looks nice, it's warm and it does the job. the skill is to select the right cut from the right timber. the finish is how it feels for playability

has anybody mentioned Young's Modulus yet?

Nope, and thanks for bringing it up!

check it out and you'll see why the the best necks are 1/4 sawn maple. the finish is irrelevant to the sound (solid bodies), it just protects from stains. timber is a good, strong, build material, natural fibre reinforced technology. it has limitations, it's hygroscopic so it moves but it looks nice, it's warm and it does the job. the skill is to select the right cut from the right timber. the finish is how it feels for playability

I hear people all the time trying to say that a thick poly finish on a solid body damps the sound. Of course that's nonsense, but it seems to be the prevailing wisdom, or lack there of.

It might effect an acoustic, but in now way has any effect on a solid body. A flexible neck kills more tone than any other factor, in my opinion. This is why carbon/graphite reinforced necks are so even sounding and have no dead spots.

THANKS. HERE'S SOMETHING ELSE I'LL BRING UP.
ALSO, SINCE NO SUGGESTIONS ABOUT NON STICK FINISHES, I CONTACTED BEHLEN. THEY WERE VERY INFORMED WITH EXCELLENT ADVICE. CONTACT THEM AT http://www.behlen.co.uk.