Nitrocellulose vs. Other Finishes

Re: Completed the set! Updated with a slight tale of woe!

capnjuan said:

Dave Gonzalez talking about the virtues of nitrocellulose at 3:35 " ... helps the guitar breathe ... helps it be more resonant ... "

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As a woodworker, I always get a good laugh at those kinds of statements. Pure marketing fluff. First, the wood does not need to breathe, it is already quite dead. Kind of along the lines of some wood care products that are marketed as "feeding" the wood. Absolute nonsense. If wood is dry and isolated from moisture and oxygen, it will last forever. No need for air or food to keep it around. Some pieces of ancient Chinese furniture with old "Chinese lacquer" are pristine after thousands of years because the finish totally isolated the wood from the atmosphere.

Second, the main reason a finish is put on wood is to seal the wood from moisture. We don't want the wood to "breathe" through the finish 'cause that would mean that moisture can get through the finish into the wood. On a guitar, that is a moot point because the inside surfaces are unfinished anyway. Mr. Gonzalez can rest easy that none of his precious guitars will suffocate since the wood can still breath from the inside. :mrgreen:

So, given the fact that the finish on a guitar is not really for isolation from moisture, it's function is to prevent damage from liquid contact (perspiration, spills, etc.) and to give some protection from physical damage.

Yes, the California limits on VOC emissions were a driving factor to move away from Nitro lacquer, but that does not negate or diminish that fact that the finishes that were developed as a result are superior to nitro lacquer in moisture insulation and are physically more durable. That would be like saying that a diesel train locomotive was only developed because steam locomotives were expensive to maintain. It's not the driving initiative that is important. The significance is in the superior product that is developed.
So saying that the new UV or catalyzed finished are only put on to speed production is not a complete argument. The new finish had to be at least as good as Nitro to be viable.

Nitro was used in past manufacturing because it was faster than the available varnishes. Nitro will dry to a sandable hardness in just a couple of days, and the next application melts into the previous layer. Neither of those facts were/are true with the older (non-catalyzed) varnishes. Old instruments were finished with various varnishes. It was probably Martin that moved to Nitro to speed things up in production of guitars. I doubt that they were worried about better tone.

Jim, I'm curious as to what makes you think that a Nitro finish is superior? You can find great sounding guitars with different finishes. It's not that Nitro finished guitars are the only ones that sound good.

Re: Completed the set! Updated with a slight tale of woe!

cjd-player said:

capnjuan said:

Dave Gonzalez talking about the virtues of nitrocellulose at 3:35 " ... helps the guitar breathe ... helps it be more resonant ... "

Click to expand...

As a woodworker, I always get a good laugh at those kinds of statements. Pure marketing fluff. First, the wood does not need to breathe, it is already quite dead. Kind of along the lines of some wood care products that are marketed as "feeding" the wood. Absolute nonsense. If wood is dry and isolated from moisture and oxygen, it will last forever. No need for air or food to keep it around. Some pieces of ancient Chinese furniture with old "Chinese lacquer" are pristine after thousands of years because the finish totally isolated the wood from the atmosphere.

Second, the main reason a finish is put on wood is to seal the wood from moisture. We don't want the wood to "breathe" through the finish 'cause that would mean that moisture can get through the finish into the wood. On a guitar, that is a moot point because the inside surfaces are unfinished anyway. Mr. Gonzalez can rest easy that none of his precious guitars will suffocate since the wood can still breath from the inside. :mrgreen:

So, given the fact that the finish on a guitar is not really for isolation from moisture, it's function is to prevent damage from liquid contact (perspiration, spills, etc.) and to give some protection from physical damage.

Yes, the California limits on VOC emissions were a driving factor to move away from Nitro lacquer, but that does not negate or diminish that fact that the finishes that were developed as a result are superior to nitro lacquer in moisture insulation and are physically more durable. That would be like saying that a diesel train locomotive was only developed because steam locomotives were expensive to maintain. It's not the driving initiative that is important. The significance is in the superior product that is developed.
So saying that the new UV or catalyzed finished are only put on to speed production is not a complete argument. The new finish had to be at least as good as Nitro to be viable.

Nitro was used in past manufacturing because it was faster than the available varnishes. Nitro will dry to a sandable hardness in just a couple of days, and the next application melts into the previous layer. Neither of those facts were/are true with the older (non-catalyzed) varnishes. Old instruments were finished with various varnishes. It was probably Martin that moved to Nitro to speed things up in production of guitars. I doubt that they were worried about better tone.

Jim, I'm curious as to what makes you think that a Nitro finish is superior? You can find great sounding guitars with different finishes. It's not that Nitro finished guitars are the only ones that sound good.

Click to expand...

I have no personal knowledge Carl as I don't own a poly finished guitar, nor have I been involved in woodworking since high school, but I could probably post a few articles here about the attributes of nitro finishes over poly. I will later if you like, but off to a birthday dinner for my father in law right now. Y'all have a good one.

But for starters...

http://www.cbguitars.com/finishes.htm

West

Re: Completed the set! Updated with a slight tale of woe!

West R Lee said:

...do poly finishes touch up like nitro?

West

Click to expand...

Nope. West, I'll repost my earlier comment from this thread...

hideglue said:

cjd-player said:

I won't buy the argument that a Nitro finish sounds better... It's an old, obsolete finish material.

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Sonic differences are subjective; much like Wooly Mammoth pins and fairy dust. And while credible manufacturers and
builders have successfully made the step to alternative finishes (Guild actually made a half-hearted attempt at UV finish in the '90s), I still think lacquer is a repairman's best friend. Obsolete? I hope not.

Click to expand...

Re: Completed the set! Updated with a slight tale of woe!

cjd-player said:

capnjuan said:

Dave Gonzalez talking about the virtues of nitrocellulose at 3:35 " ... helps the guitar breathe ... helps it be more resonant ... "

Click to expand...

As a woodworker, I always get a good laugh at those kinds of statements. Pure marketing fluff. First, the wood does not need to breathe, it is already quite dead. Kind of along the lines of some wood care products that are marketed as "feeding" the wood. Absolute nonsense. If wood is dry and isolated from moisture and oxygen, it will last forever. No need for air or food to keep it around. Some pieces of ancient Chinese furniture with old "Chinese lacquer" are pristine after thousands of years because the finish totally isolated the wood from the atmosphere.

Second, the main reason a finish is put on wood is to seal the wood from moisture. We don't want the wood to "breathe" through the finish 'cause that would mean that moisture can get through the finish into the wood. On a guitar, that is a moot point because the inside surfaces are unfinished anyway. Mr. Gonzalez can rest easy that none of his precious guitars will suffocate since the wood can still breath from the inside. :mrgreen:

So, given the fact that the finish on a guitar is not really for isolation from moisture, it's function is to prevent damage from liquid contact (perspiration, spills, etc.) and to give some protection from physical damage.

Yes, the California limits on VOC emissions were a driving factor to move away from Nitro lacquer, but that does not negate or diminish that fact that the finishes that were developed as a result are superior to nitro lacquer in moisture insulation and are physically more durable. That would be like saying that a diesel train locomotive was only developed because steam locomotives were expensive to maintain. It's not the driving initiative that is important. The significance is in the superior product that is developed.
So saying that the new UV or catalyzed finished are only put on to speed production is not a complete argument. The new finish had to be at least as good as Nitro to be viable.

Nitro was used in past manufacturing because it was faster than the available varnishes. Nitro will dry to a sandable hardness in just a couple of days, and the next application melts into the previous layer. Neither of those facts were/are true with the older (non-catalyzed) varnishes. Old instruments were finished with various varnishes. It was probably Martin that moved to Nitro to speed things up in production of guitars. I doubt that they were worried about better tone.

Jim, I'm curious as to what makes you think that a Nitro finish is superior? You can find great sounding guitars with different finishes. It's not that Nitro finished guitars are the only ones that sound good.

Click to expand...

Agree 100%. So does J. Suhr, who probably knows a bit about finishes: http://www.thegearpage.net/board/showpo ... stcount=48

I've got a longtime luthier friend who builds very high end customs. I asked about nitro, which he still offers as an expensive option on his customs. His reply was (paraphrasing): "I do for two reasons only--some customers want it & will pay for it. Easier to just do it than talk em out of it. Though I always tell them that does nothing to improve tone or longevity vs. a good poly finish."

Re: Completed the set! Updated with a slight tale of woe!

cjd-player said:

capnjuan said:

Dave Gonzalez talking about the virtues of nitrocellulose at 3:35 " ... helps the guitar breathe ... helps it be more resonant ... "

Click to expand...

Pure marketing fluff. Or puff.

First, the wood does not need to breathe ... Mr. Gonzalez can rest easy that none of his precious guitars will suffocate since the wood can still breath from the inside. Besides, if nitro were so important to the wood of a guitar being able to breathe, then why doesn't Guild put it on the inside of the guitar ... doubling the total square area of breathing surface? Arguably, aren't they just cutting cost corners by not finishing the interiors to enhance breathing? :wink:

Yes, the California limits on VOC emissions were a driving factor to move away from Nitro lacquer ... Speaking of marketing and since most states have limits on the use of VOCs through the requirement for Permits, I wonder if Mr. Taylor's remark isn't more marketing, that is: "We at Taylor are greener ( :mrgreen: ) than anyone (Guild) who still uses VOC-containing nitro"

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There's an irony here ... the finish that apparently protects better - poly - is harder to repair to cosmetic satisfaction than the finish that doesn't do as well at resisting casual damage - nitro.

I don't follow Taylor guitars on eBay but wonder if any / how many Taylors exhibit thermal stress fractures?

Re: Completed the set! Updated with a slight tale of woe!

Jim, the guy in your article just states that a thick polyurethane finish (read: "made in China") can dull the tone on a guitar. That’s probably true, but he does not state how thick is too thick. He does not really make a case for nitro being a superior finish.

We need to define “poly” here. Poly as in polyurethane varnish can be sprayed on too thick as is often seen on cheaper far-east imports. It can be used successfully on a guitar, but it is not a spray-and-forget finish.

The companies and independent luthiers I cited above are using “poly” as in polyester. The polyester finishes are cured in a few seconds by ultraviolet light. They were developed for use on metal in the auto industry. As such, they are very durable in resistance to atmospheric conditions. They had to be modified to work on wood, but now they do. They are also very thin.

Back to your article. The scientist/engineer in me laughs at his statement that an instrument finish must be “acoustically transparent”. Aside from this guy pulling a 25-cent term from his bottom to make himself sound impressive, who says so? Has he done rigorous testing to establish the resonance of a piece of tone wood, then added different types of finishes in thicknesses varying by just a few thousandths of an inch and retested? Of course not. Some would argue that a finish can improve the stiffness of the top and alter the way it vibrates in a positive way. Anyway, he certainly did not make a case for nitro being a superior finish to modern finishes

I just can’t buy the argument that the type of finish audibly effects the tone of a guitar.
I doubt that any of us would sit down and play a guitar and say, “Wow, this guitar would sound so much better in the finish was 0.002 inch thinner” (that’s 50 microns for our non-US friends. Must be politically correct with dimensions. :mrgreen, or if it was nitro versus XYZ.

I keep coming back to independent luthiers like James Olson who sell guitars with prices in the five figure range (that’s after the decimal point). Many of them subcontract the spray finishing and could select any finish they want. Yet, increasing numbers of them are going to the UV-cured polyester or catalyzed finishes simply because the finishes are better than nitro. They are more durable and protect the guitar better. And there are no worries about cold checking and contact with plastics. I doubt that these guys sit around and bemoan the fact that their guitars would sound so much better if they used nitro lacquer.

Repairs: Some Taylor repair techs can spot repair the UV-cured polyester finishes. Pat DiBurro is one http://www.diburro.com/. It takes special training and equipment, but it can be done.

Capt’n: Cold-checking: Not a scientific or all-encompassing sampling, but on the Acoustic Guitar Forum there has never been a report of cold checking of a UV-cured Polyester finish. There have been some issues of moisture getting under and lifting the finish at the exposed edge under a tuner post (people living in very humid Asian climates), but so far (about 10 years) these finishes have been impervious to cold checking (stress fractures).

I think the bottom line is to buy and play the guitar that sounds the best to you. And that is always the case. Just be aware that a nitro cellulous finish is more delicate and prone to more problems than a modern finish.

So Jim, what did you have for dinner, and did you save a piece of dessert for me? :mrgreen:

Re: Completed the set! Updated with a slight tale of woe!

I think cjd hit the nail on the head; finish is used for protection and aesthetics only. Any claims about guitars being "sealed" from moisture is bunk -- except if you interpret that to mean that a finished outside body prevents coffee spills and whatever from penetrating right into the wood, which is true of course. I don't know if any of you guys have wooden floors in your homes, but oak floors are very common up here in New England. Floor boards are finished on their outer surface. The finishes on these boards only protects them from spills and makes them look nice; it doesn't stop shrinkage in winter when RH drops (or conversely swelling in summer). For the record, I don't think nitrocellulose is used on floors; I think mine are polyurethane. Taylor uses UV-cured polyester.

The finishing process is one of the most highly experimental facets of guitar construction for some luthiers I talk to. The materials and the thickness are very important to these guys. Some even consider what their guitars will look like in 10 or 20 years down the road.

I should make a note here that the folks in New Hartford today are very concerned and interested in the importance of Guild finish to the buying process. You guys may not be aware how difficult and time-consuming it is to make a perfect Traditional Series guitar. You're talking about several weeks as multiple coats have to dry and then buff out.

Oh, final point, you guys are absolutely right that nitro is inferior to plastic finishes in terms of protecting the body. Nitro is subject to clouding from perspiration, melting from contact with rubber, and of course checking from thermal/impact exposure. But, again, that's only one dimension.

Re: Completed the set! Updated with a slight tale of woe!

Ribeye steak Carl, salad and a wonderful bacon, cheese and potato conglomeration....topped off with red velvet cake with cream cheese icing.......very dietetic.

So you guys are saying this Dave Gonzalez with Guild is dead wrong? :? And Guild should be finishing their guitars in polyester because it is superior to nitro?

West

Re: Completed the set! Updated with a slight tale of woe!

Hi Carl:

Science on the subject: if there were something definitive on nitro out there, the proponents would be using it to justify nitro.

Cold-checking of Taylor finishes: thank you ... you've saved me hours of searching the AGF and eBay.

Re: Completed the set! Updated with a slight tale of woe!

Here is a link to a thread of the venerable Kim Walker's (the name should be very familiar to this forum) beautiful work. And he ain't using lacquer. Obviously I think alternative finishes is an important talking point on guitar building, so when a builder like Kim bucks an "old guard" trend -- who am I to argue?

Re: Completed the set! Updated with a slight tale of woe!

West R Lee said:

[ ... ]So you guys are saying this Dave Gonzalez with Guild is dead wrong? :? And Guild should be finishing their guitars in polyester because it is superior to nitro?

West

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Well, the day that Taylor introduces a "Traditional" series we can all laugh.

Actually, I was going to pose this as a question... would you buy a D-55 finished in polyester? And then I remembered who I was talking to!

Guild is exploring any options that make sense, Jim. The Standard Series guitars are still nitro-finished, but a different base filler is used which significantly reduces the finishing time. Future series might change that in an effort to bump volume (and therefore factory throughput). But, in all seriousness, Guild equates Traditional with nitro -- at least for now.

Re: Completed the set! Updated with a slight tale of woe!

West R Lee said:

... So you guys are saying this Dave Gonzalez with Guild is dead wrong? :?

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Not so much wrong Jim ... he's mostly passing sales gas Saying things to generate a kind of 'zen' appreciation of intangible attributes. That somehow a guitar that breathes seems like a good idea ... who could be against a guitar being able to breathe?

I'd have been just as happy if he'd said they do it because it's a long-standing tradition that yields a lustrous (and repairable) finish; I mean he could have just said why they use it and let it go at that ... instead, he blows smoke ...

Re: Completed the set! Updated with a slight tale of woe!

hideglue said:

Here is a link to a thread of the venerable Kim Walker's (the name should be very familiar to this forum) beautiful work.

Click to expand...

Jeepers :shock: :shock: :shock: :shock: :shock:

Re: Completed the set! Updated with a slight tale of woe!

hideglue said:

Here is a link to a thread of the venerable Kim Walker's (the name should be very familiar to this forum) beautiful work. And he ain't using lacquer. Obviously I think alternative finishes is an important talking point on guitar building, so when a builder like Kim bucks an "old guard" trend -- who am I to argue?

Click to expand...

Kim's guitars are quite extraordinary. Has he published anything where he discusses finishes? All I found about flattops on his website was this:"Each one of my guitars come standard finished with a gloss varnish. This fabulous finish is very durable, has a warm glow and helps impart that dry vintage tone."

Another significant point from hideglue. Keep 'em rolling in, sir.

Is it harder for poly to get weather checking?

Re: Completed the set! Updated with a slight tale of woe!

cjd-player said:

We need to define “poly” here. Poly as in polyurethane varnish can be sprayed on too thick as is often seen on cheaper far-east imports. It can be used successfully on a guitar, but it is not a spray-and-forget finish.

The companies and independent luthiers I cited above are using “poly” as in polyester. The polyester finishes are cured in a few seconds by ultraviolet light. They were developed for use on metal in the auto industry. As such, they are very durable in resistance to atmospheric conditions. They had to be modified to work on wood, but now they do. They are also very thin.

Click to expand...

I find this fascinating if only because I thought a "poly finish" on a guitar meant the same thing to everyone. What are the differences between the two types of polys? I know the first type is easier to apply - can be sprayed on - but is also very easy to apply in greater quantities than required. The too thick finish detracts from aesthetics and probably tone and/or volume. The first type of poly is likely to be found on low end, low priced guitars and probably most Chinese imports. what else have I missed? Who is using the other type of poly? Which market niche does it show up in today?

Thanks.

Re: Completed the set! Updated with a slight tale of woe!

fronobulax said:

I find this fascinating if only because I thought a "poly finish" on a guitar meant the same thing to everyone. What are the differences between the two types of polys?
...The first type of poly is likely to be found on low end, low priced guitars and probably most Chinese import...

Click to expand...

Don't forget about the amount of polyurethane sprayed at Westerly.

Re: Completed the set! Updated with a slight tale of woe!

hideglue said:

fronobulax said:

I find this fascinating if only because I thought a "poly finish" on a guitar meant the same thing to everyone. What are the differences between the two types of polys?
...The first type of poly is likely to be found on low end, low priced guitars and probably most Chinese import...

Click to expand...

Don't forget about the amount of polyurethane sprayed at Westerly.

Click to expand...

I had. Thank you. All part of the educational process.

What the fro said.

Re: Completed the set! Updated with a slight tale of woe!

capnjuan said:

hideglue said:

Here is a link to a thread of the venerable Kim Walker's (the name should be very familiar to this forum) beautiful work.

Click to expand...

Jeepers :shock: :shock: :shock: :shock: :shock:

Click to expand...

I may be the odd man out, but finish checking doesn't bother me. I'm not much of a woodworker and I'm certainly not a chemist, but on a wonderful old vintage instrument an aged look to the finish is an enhancement to me. That's why any reputable antique dealer will discourage refinishing old wood. I think there may also be some value in doing things "by hand", the old, more time consuming way.

I checked that link and those guitars are stunning! There is at least one picture (bottom, 1st page) where you can see the 'print' of the wood. Applied that thinly, I doubt if there is any sound difference to a new instrument, although it would be interesting to see if it "breaks in" any differently. When poly is applied that thinly it may be fine, but as far as I know it doesn't 'age', and that may offset the advantages of a more resilient finish.

I don't normally see myself as a stodgy traditionalist, but if someone wanted to put a nice coat of modern poly on a Stradivarius, I'd urge them to reconsider.