Nitrocellulose vs. Other Finishes

[curt]

For a more percussive sound, why not finish the guitar with nitroglycerine?

No need... Nitrocellulose is explosive enough. See: http://en.wikipedia.org/wiki/Nitrocellulose#Uses

We use nitrocellulose membranes in the lab... I can vouch that they are quite flammable.

Check out what celluloid binding does.

http://www.youtube.com/watch?v=rDIvVhIBbuk

 

[hideglue]

EDIT

**nevermind** I got it. S-L-O-W

 

[adorshki]

I can hear a difference between the dry winter and humid summer.

:lol: Reminds me of the Grateful Dead telling the Warner Brothers engineers they were trying to record the sound of "fuzzy air". Uh oh I just figured out you meant, "in the way my guitar sounds" :lol:

 

[West R Lee]

From Collings.....right here in Texas :wink: .

http://www.youtube.com/watch?v=valB38pbXYI

West

 

[hideglue]

HG,

As far as sound goes, poly vs nitro wouldn't matter nearly as much on a solidbody right?

dh

Walter answered this a lot better than I ever could. But if we're sticking to Guilds, the answer yes... right. Apparently so. And certain models of hollowbodies as well.

 

[capnjuan]

... Lacquer is the ONLY way to go on an acoustic, the thinner and more dried out the better.

Hi Curt: by lacquer ... do you mean nitro or conventional lacquer? If nitro, why is it the only way to go? This isn't a trick question; I'm interested in knowing why a pro would be so strong on the product.

Yes nitrocellulose lacquer. I like it because it's proven, dries hard, transmits sound and you can't match the feel or look.

Okay; thank you.

 

[chazmo]

Would you buy a polyester-finished Guild?

After our interesting discussion about finish options (viewtopic.php?t=24274), I thought I'd pose a hypothetical question to folks.... Would you buy a (US-built) Guild acoustic -- or let's say a future hollow-body too -- with a polyester finish? And, would your expectations be that it would *have* to be cheaper than an equivalent nitrocellulose-lacquered guitar? And, let's take this one step further, would you buy a D-55 or an F-50 (i.e., the "premium" Traditional series) with a polyester finish?

I think the answer is "yes" (at least for me it is). I hope this poll captures what I'm asking.

[edit: oh, and if you wouldn't buy a new Guild anyway -- you know who you are -- feel free to vote anyway; I'm interested in all opinions]

 

[chazmo]

Hey, place your vote, folks: viewtopic.php?t=24313

Just curious what folks would do...

 

[fronobulax]

I will say this, and it's just personal opinion. If I were a major guitar manufacturer, or a little guy for that matter, I doubt I would say....."Hey, we'd like to use nitrocellulose lacquer, but it takes too long, costs too much money and puts us at odds with the EPA, so we give you a UV polyeurathane finish. It just easier!" So they say it's harder (no doubt) and equal to or better than nitro.

Classic marketing. I want to do X but economics and other factors compel me to do Y so I will try and convince folks that the decision was made in order to improve the product rather than admit it was a decision driven by money and Government Regulation! :wink: "Easier for us" doesn't always work as well as "Better for you".

The whole discussion is fascinating. I find the lack of science (in the sense of repeatable measurements) dooms the discussion to the realm of opinion. I suspect if we wanted to bring research to bear we should probably start with the investigations that ask "what makes a Stradivarius (as opposed to a Stratocaster) sound the way it does? and can we replicate that sound in instruments and finishes from today?"

 

[fronobulax]

Re: Would you buy a polyester-finished Guild?

Note that the poll is about polyester finishes and not polyurethane finishes.

From the other thread...

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.

 

[chazmo]

Re: Would you buy a polyester-finished Guild?

I could be wrong about this, but I think polyester is the most likely, modern finish alternative that would be considered by the factory.

 

[chazmo]

While ventilation and environment concerns were mentioned earlier, I don't know if long-term exposure to nitrocellulose lacquer was discussed here yet. Let's just say it isn't good for you and it has probably shortened the lives of some of the people who've worked with the stuff on a daily basis.

 

[fronobulax]

Re: Would you buy a polyester-finished Guild?

I could be wrong about this, but I think polyester is the most likely, modern finish alternative that would be considered by the factory.

Everything I know on the subject I learned from cjd-player but when I hear polyurethane I think of a nautical themed restaurant that used hatch covers as tables. They were finished with a clear coating that was at least 1/4 inch thick and you could see that even in the dim lighting. I think some cheap and/or non-U.S. made guitars have that finish.

Polyester in the context of a guitar finish (as opposed to a fashion faux pas from the '70's) is different if only because it can be and is applied in thinner layers.

Personally I think much of the prejudice against "poly" finishes is from people who don't make the distinction. Even I don't want a finish that reminds me of a restaurant table.

 

[fronobulax]

HG,

As far as sound goes, poly vs nitro wouldn't matter nearly as much on a solidbody right?

dh

If we want another veer let's talk about the factors that contribute to the sound of a solid body. Once you get beyond the pickups and the density of the woods used people are pretty hard pressed to back up opinions with research or "science".

(As a wondergraduate, I built a one string bass, wound my own pickups, mounted them so I could get a picture of the string's vibration along two dimensions (with the string length being the unmeasured third dimension) and looked at the effects of "attack" on tone. Thus, at least for right handed bass players, I firmly believe right hand technique has a much greater effect on tone than, say, which finish was used).

 

[curt]

I'll qualify what I'm going to say by saying I am a wholesale distributor of automotive refinish products, paint and deal with VOC regulations daily.

VOC regulations are the result of reducing smog which on paper is a great thing. They don't care about the worker spraying the stuff. The current poly's are are much more toxic to the worker than nitrocellulose lacquer is. If you've heard of Imron you'll know that it's way toxic but the VOC people LOVE Imron because of it's high solid low solvent make up. Lacquer was to be banned in the USA because of the amount of low level ozone, smog, it produces because of it's low solid high solvent mix. Here's where it gets interesting, the government made an exemption for acetone which is a fast flashing solvent and allows products that couldn't comply, comply. Which is where lacquer got a new lease on life, the only problem is that the smog issue remains since nothing's really changed.

trust me on this, a painter would rather be using lacquer based products than ones that require isocyanate to cure.

 

[Ridgemont]

Re: Would you buy a polyester-finished Guild?

Interesting choices. But I am going to abstain from voting as I do not know. I agree that there is prejudice against poly from the more traditional crowd who are looking for traditional guitar. But as far as sound differences to my ear? I have not sampled a big enough pool to draw a conclusion.

 

[chazmo]

Curt,

That is very interesting information.

Your point about the intent of the regulations is no doubt correct, but where do you get the information that polyester is more dangerous to the workers than nitrocellulose? I hadn't heard that before, but I am a layman on the subject and freely admit my ignorance!

I should make note of the fact that the process that Taylor uses with polyester involves electrically charging the body of the guitar while spraying it in a booth with a robot. After that, the guitar is cured in UV light booth (I don't know if isocyanate is needed for that). Very little exposure to workers -- nice application of robotics.

 

[curt]

Re: Would you buy a polyester-finished Guild?

Keep in mind that polyester will remain water clear, no aging and that you can't repair a spot, you need to address the entire surface. Then there's the warm glow of lacquer that you just can't even come close with polyester.

 

[curt]

Curt,

That is very interesting information.

Your point about the intent of the regulations is no doubt correct, but where do you get the information that polyester is more dangerous to the workers than nitrocellulose? I hadn't heard that before, but I am a layman on the subject and freely admit my ignorance!

I should make note of the fact that the process that Taylor uses with polyester involves electrically charging the body of the guitar while spraying it in a booth with a robot. After that, the guitar is cured in UV light booth (I don't know if isocyanate is needed for that). Very little exposure to workers -- nice application of robotics.

I was talking more about polyurethane and not ester, but there is a catalyst involved to kick it.

The other issue with any lacquer is that it emits solvents for years, progressively less every day but that's what you smell when you open the case. What the government likes about catalyzed products is that most of the solvents are released in a short period of time. Keep in mind that a 16lb gallon of clear emits about 8lbs of VOC.

On the Taylor subject, I am not a fan of their finishes, bolt on neck or the two piece headstock but they seem to be doing quite well in the market.

 

[capnjuan]

... I find the lack of science (in the sense of repeatable measurements) dooms the discussion to the realm of opinion. I suspect if we wanted to bring research to bear we should probably start with the investigations that ask "what makes a Stradivarius (as opposed to a Stratocaster) sound the way it does? and can we replicate that sound in instruments and finishes from today?"

Hi Frono; Referring only to resonance and dismissing breathing (although all members should continue to do so), it would be possible to take laboratory measurements of guitars tops ... tops only; with nitro and with something/anything else. Comparative vibration properties could be measured and conclusions drawn; a top with finish X cycles less frequently while a top with finish Y cycles more quickly ... and then there's the rest of it; in response to bass notes ... in response to treble ... in response to chords.

It isn't clear given the rest of the variables;
the wood species,
age,
the stage of the moon at time of harvest (and whether a clergyman was present),
average thickness,
bracing materials and layout,
moisture content, and
the degree of top crown and the tension that it's under,

That the finish on the top as it's attached to the guitar is the only meaningful variable that could reasonably be expected to influence resonance and, by extension, tone. I'm not sure there's any way to know what role finish alone plays in resonance. If it (apparently) isn't possible to produce identical guitars - both with the same finish - with identical tone, I don't know how it's possible to compare two identical guitars with mis-matched finishes.