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SHOW YOUR DISTRESSED FINISHES!
- Thread starter JIO
- Start date
- Jun 30, 2010
- 49,612
- 222,126
- Disclosures
- musician/artist/owner - Gildaxe
This might be a bit much but I thought since it's so relevant to the thread I'd post it. I found it while doing "research". Ha and lifted it from a les Paul forum. If I poached this from our own geo, I appologize. I also appologize for the edits leaving out most of the comments save for a few of the more relevant ones.
- Invalid Link Removed
Invalid Link RemovedV.I.P. Member
How does nitrocellulose lacquer and common dyes used in guitars fade?
This question has recently been asked of me by a member here and there seems to be interest on how and why this happens, so I put together a basic write up to help explain what goes on.
Almost everyone here knows that 'light' does the fading. But how and why does that happen? Maybe I can shed some 'light' on the issue.
First we have to understand some things about light and the electromagnetic spectrum, and polymers.
Light:
The electromagnetic spectrum is a continuous range of frequencies and energies, with visible light occupying a small portion of the whole.
The sun puts out electromagnetic energy throughout the whole spectrum. What interests us is the visible spectrum and the ultraviolet range.
In 1887, the photoelectric effect was discovered by Heinrich Hertz, as he was experimenting with radio waves. He was not particularly interested in the phenomenon, but he did notice that the effect was produced strongly by ultraviolet light and more weakly by lower frequencies. Light whose frequency was lower than a certain critical value did not eject any electrons at all. Why is this important?
A light wave consists of electric and magnetic fields. The stronger the fields, i.e., the greater the wave's amplitude, the greater the forces that would be exerted on electrons that found themselves bathed in the light. Light excites electrons with enough energy to break atomic bonds, but light also enables us to see colors.
We see those colors because they reflect light back to our eye from very specific parts of the visible-light portion of the electromagnetic spectrum. Unfortunately, what's not reflected is absorbed, and that's where the trouble starts.
Light is energy, and when that absorbed energy equals or exceeds the so-called 'activation energy' of a molecule in a dye or pigment, the molecule becomes "excited," meaning, rendered available for chemical reactions. If your dye is chemically active, it means it's interacting with the environment and becoming chemically altered. A number of things, many of them destructive, can happen once a molecule gets excited. The extra energy may be converted to heat (infrared energy) or emitted as light (phosphorescence or fluorescence). It can break chemical bonds within the molecule, breaking the dye down.
Generally speaking, organic materialsthose derived from plants or animalsare more susceptible than inorganic materials. For instance, natural dyes, which are organic, generally fade faster than pigments, which are usually comprised of inorganic minerals.
The older red organic dyes are more susceptible to fading because of the organic chemical makeup and becuase they look red and thus absorb blue, which is the higher-energy light.
The energy from light can also jump to another molecule. In one of the most damaging of such leaps, the energy transfers to an oxygen molecule, which can then react with other molecules to jumpstart chemical reactions. Oxidation takes place, bleaching out the color.
But that's not all. There can be synergistic effects: with higher temperature and humidity, for example, reactions catalyzed by electromagnetic radiation can occur more rapidly. And there can be chain reactions: new substances formed as a result of photochemical reactions will have enough energy to also react with the original substance, launching a chain reaction of degradation. Something to keep in mind is chemical reactions initiated by light can continue even after the object is placed in the dark.
The ultraviolet wavelengths of interest are:
UVA: 320 - 400nm SKIN TANNING
UVB: 280 - 320nm SKIN BURNING
UVC: 100 - 280nm INDUSTRIAL GERMICIDAL USE.
All types of UV can cause a photochemical effect within the polymer structure. It is the high energy UVC wavelengths that are produced by the Sun, and not by artificial lights except in industrial use that cause the most degradation to polymers.
Polymers:
Lacquer refers to polymers dissolved in volatile organic compounds (VOCs), such as nitrocellulose, and later acrylic compounds dissolved in lacquer thinner, a mixture of several solvents typically containing butyl acetate and xylene or toluene. A polymer is a long chain of molecules that repeats a pattern of atoms. These molecular groups are tied together through bonding of electrons.
Like with dyes, one of the main problems of considering the effect of UV rays on polymers is the intensity related to: stratospheric ozone, clouds, altitude, the position of the sun height (time of day and time of year), and reflection.
The main visible effects in polymer degradation are a chalky appearance and a color shift on the surface of the material, and the component surface becomes brittle. Often a fluorescent whitening agent (FWA) is added to the polymer. In natural light many polymer products can appear to have a yellow appearance. But by adding a FWA the UV light absorbed is then emitted in the blue region of visible light (400-500nm wavelength), instead of the yellow region. When we shine an UV flourescent light on a finish to check its consistancy, this is the blue light that we see from this additive.
As the polymer breaksdown over time and exposure, the color returns to the yellow that we associate with 'old' nitro finishes.
UV energy absorbed by polymers can excite photons, which then create free radicals. While many pure polymers cannot absorb UV radiation, the presence of catalyst residues and other impurities will often act as receptors, causing degradation.
Only a very small amount of impurity may be needed for the degradation to occur, e.g. trace parts per billion values of sodium in polycarbonate will initiate color instability. In the presence of oxygen the free radicals form oxygen hydroperoxides that can break the double bonds of the backbone chain leading to a brittle structure. This process is often called photo-oxidation. However, in the absence of oxygen there will still be degradation due to the cross-linking process.
As there is an interest in artificially aging guitars, a few things have to be considered. Many of the lacquers used in the 1950's are not of the same formulae as todays. Many new UV blockers, plasticizers, and stabilizers have been added. UV bulbs do not produce the same spectrum as the Sun, so the results will not be the same. As with the lacquers, todays dyes have more inorganic components to stabilize them than in the past.
I hope that this has been helpful.
Invalid Link Removed, Invalid Link Removed
I've had my guitar in the sun almost daily for a couple weeks now, and the only change I've been able to discern is with the clear/amber area on the belly of the guitar top. I didn't notice that change until I pulled the pickup rings off, might not be from the past couple weeks even. It's getting lighter.
From what I've read in your post, I'm thinking that the amber dye is fading faster than the nitrocellulose lacquer is yellowing, and the red dye is so well protected by additives that it's not fading at all, or so slightly that I can't tell. But it also seems like at some point, the UV blockers and plasticizers themselves will start to break down, and eventually, the nitro will yellow, and the red will break down to something else, whatever that something else may be.
- Thanks very informative.... i wish we could gather info on the various types of formulas used to finish the guitars then we could simply spray a few test strips and expose them to different types of light to determine which would be the best frequency to fade specific types of finishes
- Invalid Link Removed
Thanks very informative.... i wish we could gather info on the various types of formulas used to finish the guitars then we could simply spray a few test strips and expose them to - I guess some people are content with reading the various extant threads, which is cool, but I'm very interested in the science behind fading, which hasn't been explained until this thread...
I know Mike has faded some guitars using natural sunlight, and the results look fantastic. These are newer guitars, presumably with at least some UV blockers in the lacquer. I've read a couple of threads recently in which people were considering using artifical UV light, which seemed a bit dodgy to me at first glance, and which actually does produce a different result than fading by sunlight, because all the artificial UV sources create UV at very specific frequencies, wheras sunlight is broadband, so to speak.
Not sure if it was on MLP or not, but one guy somewhere said he "blasted" his LP with so much UV that the plastic partially disintegrated. True? I dunno, but I'd like to know what he used to "blast" UV, mebbe a tanning bed?
Right now I'm wondering about how UV blockers work, if they somehow absorb UV for a time and then break down, or perhaps raise the activity threshold of the polymers around them.
- Invalid Link Removed
Thanks very informative.... i wish we could gather info on the various types of formulas used to finish the guitars then we could simply spray a few test strips and expose them to different types of light to determine which would be the best frequency to fade specific types of finishes
Click to expand...
The best place to gather that sort of info would be in the Luthier's sub forum. My guess is that you probably won't get too far in determining what is actually in the formula. The Luthier's buy a stock polymer base, which would be designated by a manufacturers number, and then thin it down with the proper solvent for spraying.
Finding out the formula of the stock polymer base in detail would be near impossible as that is proprietary info. The stabilizers and additives that are added to make one finish better than another is valuable info, and separates you from the competition.
Invalid Link Removed
.....Right now I'm wondering about how UV blockers work, if they somehow absorb UV for a time and then break down, or perhaps raise the activity threshold of the polymers around them, but remain effective permanently.
I think it's damned interesting, myself. :dude:
Click to expand...
UV blockers work in various ways, the most common being as UV absorbers. What happens with most UV absorbers is that the absorbed energy has to go somewhere. Most of them emit the absorbed energy as infrared, which means the get hot. As shown in my post, heat plays a part in degrading dyes and polymers. The blockers do not prevent degradation, they just slow it down, and they eventually breakdown themselves.
The red colors, that were mostly organic in makeup, as shown by the 50's bursts (and other models) degraded rapidly, creating 'lemonbursts'. The inorganic pigments that were used on bursts starting in 1960 were made up using a higher percentage of inorganic iron oxides. Depending on the oxidative state of the iron (+2 or +3), the color can vary from a dark red to orange. This change in formula produced a color that lasted much longer, but photo-oxidation processes (as described in the post) would change the +2 (deeper red) pigment to the +3 orange pigment and result in the 'tomato soup' color of the 60 burst that collectors don't like.
I would guess that todays formulations of the red color would produce the same effect.
Invalid Link Removed
A one of one, made for me bass, gifted by my mother for Christmas. Built by gifted luthier Doug Roomian, 1987.
- Jun 30, 2010
- 49,612
- 222,126
- Disclosures
- musician/artist/owner - Gildaxe
Our guitarist for Bond Girl/The Sean Conneries 70's (big hs) Strat. Possibly originally CAR (as seen in the tremolo cavity) - a very played guitar.
- Jun 30, 2010
- 49,612
- 222,126
- Disclosures
- musician/artist/owner - Gildaxe
This might be a bit much but I thought since it's so relevant to the thread I'd post it. I found it while doing "research". Ha and lifted it from a les Paul forum. If I poached this from our own geo, I appologize. I also appologize for the edits leaving out most of the comments save for a few of the more relevant ones.
- Invalid Link Removed
Invalid Link RemovedV.I.P. Member
How does nitrocellulose lacquer and common dyes used in guitars fade?
This question has recently been asked of me by a member here and there seems to be interest on how and why this happens, so I put together a basic write up to help explain what goes on.
Almost everyone here knows that 'light' does the fading. But how and why does that happen? Maybe I can shed some 'light' on the issue.
First we have to understand some things about light and the electromagnetic spectrum, and polymers.
Light:
The electromagnetic spectrum is a continuous range of frequencies and energies, with visible light occupying a small portion of the whole.
View attachment 2830659
The sun puts out electromagnetic energy throughout the whole spectrum. What interests us is the visible spectrum and the ultraviolet range.
In 1887, the photoelectric effect was discovered by Heinrich Hertz, as he was experimenting with radio waves. He was not particularly interested in the phenomenon, but he did notice that the effect was produced strongly by ultraviolet light and more weakly by lower frequencies. Light whose frequency was lower than a certain critical value did not eject any electrons at all. Why is this important?
A light wave consists of electric and magnetic fields. The stronger the fields, i.e., the greater the wave's amplitude, the greater the forces that would be exerted on electrons that found themselves bathed in the light. Light excites electrons with enough energy to break atomic bonds, but light also enables us to see colors.
We see those colors because they reflect light back to our eye from very specific parts of the visible-light portion of the electromagnetic spectrum. Unfortunately, what's not reflected is absorbed, and that's where the trouble starts.
Light is energy, and when that absorbed energy equals or exceeds the so-called 'activation energy' of a molecule in a dye or pigment, the molecule becomes "excited," meaning, rendered available for chemical reactions. If your dye is chemically active, it means it's interacting with the environment and becoming chemically altered. A number of things, many of them destructive, can happen once a molecule gets excited. The extra energy may be converted to heat (infrared energy) or emitted as light (phosphorescence or fluorescence). It can break chemical bonds within the molecule, breaking the dye down.
Generally speaking, organic materialsthose derived from plants or animalsare more susceptible than inorganic materials. For instance, natural dyes, which are organic, generally fade faster than pigments, which are usually comprised of inorganic minerals.
The older red organic dyes are more susceptible to fading because of the organic chemical makeup and becuase they look red and thus absorb blue, which is the higher-energy light.
The energy from light can also jump to another molecule. In one of the most damaging of such leaps, the energy transfers to an oxygen molecule, which can then react with other molecules to jumpstart chemical reactions. Oxidation takes place, bleaching out the color.
But that's not all. There can be synergistic effects: with higher temperature and humidity, for example, reactions catalyzed by electromagnetic radiation can occur more rapidly. And there can be chain reactions: new substances formed as a result of photochemical reactions will have enough energy to also react with the original substance, launching a chain reaction of degradation. Something to keep in mind is chemical reactions initiated by light can continue even after the object is placed in the dark.
The ultraviolet wavelengths of interest are:
UVA: 320 - 400nm SKIN TANNING
UVB: 280 - 320nm SKIN BURNING
UVC: 100 - 280nm INDUSTRIAL GERMICIDAL USE.
All types of UV can cause a photochemical effect within the polymer structure. It is the high energy UVC wavelengths that are produced by the Sun, and not by artificial lights except in industrial use that cause the most degradation to polymers.
Polymers:
Lacquer refers to polymers dissolved in volatile organic compounds (VOCs), such as nitrocellulose, and later acrylic compounds dissolved in lacquer thinner, a mixture of several solvents typically containing butyl acetate and xylene or toluene. A polymer is a long chain of molecules that repeats a pattern of atoms. These molecular groups are tied together through bonding of electrons.
Like with dyes, one of the main problems of considering the effect of UV rays on polymers is the intensity related to: stratospheric ozone, clouds, altitude, the position of the sun height (time of day and time of year), and reflection.
The main visible effects in polymer degradation are a chalky appearance and a color shift on the surface of the material, and the component surface becomes brittle. Often a fluorescent whitening agent (FWA) is added to the polymer. In natural light many polymer products can appear to have a yellow appearance. But by adding a FWA the UV light absorbed is then emitted in the blue region of visible light (400-500nm wavelength), instead of the yellow region. When we shine an UV flourescent light on a finish to check its consistancy, this is the blue light that we see from this additive.
As the polymer breaksdown over time and exposure, the color returns to the yellow that we associate with 'old' nitro finishes.
UV energy absorbed by polymers can excite photons, which then create free radicals. While many pure polymers cannot absorb UV radiation, the presence of catalyst residues and other impurities will often act as receptors, causing degradation.
Only a very small amount of impurity may be needed for the degradation to occur, e.g. trace parts per billion values of sodium in polycarbonate will initiate color instability. In the presence of oxygen the free radicals form oxygen hydroperoxides that can break the double bonds of the backbone chain leading to a brittle structure. This process is often called photo-oxidation. However, in the absence of oxygen there will still be degradation due to the cross-linking process.
As there is an interest in artificially aging guitars, a few things have to be considered. Many of the lacquers used in the 1950's are not of the same formulae as todays. Many new UV blockers, plasticizers, and stabilizers have been added. UV bulbs do not produce the same spectrum as the Sun, so the results will not be the same. As with the lacquers, todays dyes have more inorganic components to stabilize them than in the past.
I hope that this has been helpful.
Invalid Link Removed, Invalid Link Removed
I've had my guitar in the sun almost daily for a couple weeks now, and the only change I've been able to discern is with the clear/amber area on the belly of the guitar top. I didn't notice that change until I pulled the pickup rings off, might not be from the past couple weeks even. It's getting lighter.
From what I've read in your post, I'm thinking that the amber dye is fading faster than the nitrocellulose lacquer is yellowing, and the red dye is so well protected by additives that it's not fading at all, or so slightly that I can't tell. But it also seems like at some point, the UV blockers and plasticizers themselves will start to break down, and eventually, the nitro will yellow, and the red will break down to something else, whatever that something else may be.
- Thanks
- Invalid Link Removed
Thanks- I guess some people are content with reading the various extant threads, which is cool, but I'm very interested in the science behind fading, which hasn't been explained until this thread...
I know Mike has faded some guitars using natural sunlight, and the results look fantastic. These are newer guitars, presumably with at least some UV blockers in the lacquer. I've read a couple of threads recently in which people were considering using artifical UV light, which seemed a bit dodgy to me at first glance, and which actually does produce a different result than fading by sunlight, because all the artificial UV sources create UV at very specific frequencies, wheras sunlight is broadband, so to speak.
Not sure if it was on MLP or not, but one guy somewhere said he "blasted" his LP with so much UV that the plastic partially disintegrated. True? I dunno, but I'd like to know what he used to "blast" UV, mebbe a tanning bed?
Right now I'm wondering about how UV blockers work, if they somehow absorb UV for a time and then break down, or perhaps raise the activity threshold of the polymers around them.
- Invalid Link Removed
Thanks
Click to expand...
The best place to gather that sort of info would be in the Luthier's sub forum. My guess is that you probably won't get too far in determining what is actually in the formula. The Luthier's buy a stock polymer base, which would be designated by a manufacturers number, and then thin it down with the proper solvent for spraying.
Finding out the formula of the stock polymer base in detail would be near impossible as that is proprietary info. The stabilizers and additives that are added to make one finish better than another is valuable info, and separates you from the competition.
Invalid Link Removed
.....Right now I'm wondering about how UV blockers work, if they somehow absorb UV for a time and then break down, or perhaps raise the activity threshold of the polymers around them, but remain effective permanently.
I think it's damned interesting, myself. :dude:
Click to expand...
UV blockers work in various ways, the most common being as UV absorbers. What happens with most UV absorbers is that the absorbed energy has to go somewhere. Most of them emit the absorbed energy as infrared, which means the get hot. As shown in my post, heat plays a part in degrading dyes and polymers. The blockers do not prevent degradation, they just slow it down, and they eventually breakdown themselves.
The red colors, that were mostly organic in makeup, as shown by the 50's bursts (and other models) degraded rapidly, creating 'lemonbursts'. The inorganic pigments that were used on bursts starting in 1960 were made up using a higher percentage of inorganic iron oxides. Depending on the oxidative state of the iron (+2 or +3), the color can vary from a dark red to orange. This change in formula produced a color that lasted much longer, but photo-oxidation processes (as described in the post) would change the +2 (deeper red) pigment to the +3 orange pigment and result in the 'tomato soup' color of the 60 burst that collectors don't like.
I would guess that todays formulations of the red color would produce the same effect.
Invalid Link Removed
Not me - interesting, but it's all a bit much for me...
Last edited:
Agreed but I enjoy trying to learn science above my lowly pay grade and education level. I'm often astounded how unimpressed I am with some young college grads I meet. But that's another "what's up with our education system" thread. Ok back OT.
Last Sun night I put some serious road wear on my Tune bass. Just when I was ending a solo I had the strap screw rip right out of the upper horn of my bass. Tearing a chunk of wood in the process. Some dents on it as it unceremoniously skidded off of the stage with a huge clang and bang. I went ok......hum, interesting!
Grabbed it sat down on the stage and finished the tune! I know no pics etc. But I took it by my tech buddies house and he grabbed it and started cutting out a piece of wood to repair it. He had a piece cut, fit, glued and filled in less than an hour I didn't even think to take a pic. He thinks it will be a pretty clean repair. We'll see.
Last Sun night I put some serious road wear on my Tune bass. Just when I was ending a solo I had the strap screw rip right out of the upper horn of my bass. Tearing a chunk of wood in the process. Some dents on it as it unceremoniously skidded off of the stage with a huge clang and bang. I went ok......hum, interesting!
Grabbed it sat down on the stage and finished the tune! I know no pics etc. But I took it by my tech buddies house and he grabbed it and started cutting out a piece of wood to repair it. He had a piece cut, fit, glued and filled in less than an hour I didn't even think to take a pic. He thinks it will be a pretty clean repair. We'll see.
- Jun 30, 2010
- 49,612
- 222,126
- Disclosures
- musician/artist/owner - Gildaxe
I guess you are one of those guys that should duct-tape your strap to your upper horn!
Funny story, the one other time something like this happened, my strap broke and the bass flew straight down out of my hands. It hit the very bouncy plywood stage and bounced straight up, right back into my hands and I put a foot on the monitor to hold it up and finished the song. It was the last tune of the set. And two guys immediately came up to compliment me on the show. They'd said it looked rehearsed! I laughed and said no, just good reflexes. Boy do I wish I had a vid of that. Bet you I couldn't do it again in a hundred try's. The club burned to the ground, thank god. Sometimes I feel like the Farmers guy. Yup, been there done that, covered it.
- Jun 30, 2010
- 49,612
- 222,126
- Disclosures
- musician/artist/owner - Gildaxe
(and luckily still has his hand!)
Last edited:
I've got a great Peavey Palaedium but I was never a fan of the transparent purple finish. So last weekend I decided to strip it and refinish it.
I wasn't necessarily going for a beaten-up relic look, but just kind of winged it with the stains. I did a medium brown, then put a little black over that here and there, and when it was dry, did a couple coats of tung oil.
It may not be something I'd play at a wedding, but I really like how it came out. It's definitely got a broken-in look and feel, but doesn't look abused.
I wasn't necessarily going for a beaten-up relic look, but just kind of winged it with the stains. I did a medium brown, then put a little black over that here and there, and when it was dry, did a couple coats of tung oil.
It may not be something I'd play at a wedding, but I really like how it came out. It's definitely got a broken-in look and feel, but doesn't look abused.
Last edited:
- Mar 8, 2011
- 12,232
- 51,187
- Disclosures
- Authorized greenboy designs builder/Owner of BNA Audio
- Jun 30, 2010
- 49,612
- 222,126
- Disclosures
- musician/artist/owner - Gildaxe
It does look good, like a (deliberate) light relic. Part of why is because in stripping it you left the (clear) seal-coat mostly in tact. The darker area's are where you broke through and your stains absorbed into the bare porous wood. On factory finishes the seal coat can be pretty tenacious/difficult to fully remove. I ran into this stripping a CIJ Fender '51 P RI ('96) - it was some kind of epoxy that was impervious to stripper. (at least the neutered CA version) I ended up running the front & back through a planer to get down to bare wood.
I like the angled neck plate - I don't think I've ever seen that done before.
- Mar 8, 2011
- 12,232
- 51,187
- Disclosures
- Authorized greenboy designs builder/Owner of BNA Audio
I had a brief obsession with 80’s Peavey basses awhile back. At one time I had a T-40, T-45, Foundation and Palaedium. It was a super well made, great sounding bass. The neck was just too narrow and small for what I like. I still say the T-40 neck profile is perfection. When I had my Drake made, Andrew used that profile.
Or perhaps this just a signature by Douglas Stupidawfullest. In the Custom Shop! I guess we'll never know, one can only stare in amazement and wonder.
Attachments
I've had all my friends carve their initials into the back of one of my Hofners. Glad to see someone else is being fearless!
- Jun 30, 2010
- 49,612
- 222,126
- Disclosures
- musician/artist/owner - Gildaxe
Nels Cline's '59 Jazzmaster previously owned by Mike Watt - from the book "Instrument" - photos by Pat Graham 2011 ... just a little distressed/road-worn.
