Will bubble wrap eat nitro finishes?

[GGJaguar]

the "schmutz" of life

You should submit this as an entry in the band name thread.

 

[walrus]

I recall but cannot find some LTG discussion on NCL vs. Poly as a finish and whether the thicker poly had a noticeable impact on tone. It didn't and the attempts at a science and physics based justification for that observation seem to me to apply to bare vs. finished as well.

Lots of discussion inside of this thread. Don't mistake me for Ralf, I only remember because I looked at it recently, since my Sadowsky has a nitro finish.

https://letstalkguild.com/ltg/index.php?threads/guild-finish-at-cordoba.181659/

walrus

 

[Christopher Cozad]

I'd still be interested in hearing from a Luthier who builds as well as repairs guitars for their thoughts on how finish affects sound quality, and if it lessens it, is the protection the finish offers worth that loss?

How finish affects sound quality is an interesting topic. Many postulate that any finish has a deleterious affect upon the overall tone, reasoning that all finishes add a damping aspect to the mix. There is ample measurable data to the contrary. In many cases the finish actually aids in telegraphing the kinetic energy moving across the soundboard. I do not agree that an aural loss must necessarily be experienced by adding a finish.

Of course, you don't HAVE to finish the wood but, as Tom explained, in addition to more-than-likely suffering a visual cost for not doing so there is the increased likelihood of damage.

Finish components (chemicals/compounds) vary, but the rule of thumb is "less is more." This is where a shellac or varnish (Stradivarius) shines (pun?) over a polyester, since they typically can be applied more thinly. Boiled Linseed oil (and variants) are used by several builders I know, very successfully. A new entrance to the market is Cyanoacrylate (super glue). Apart from having to wear a respirator while applying it (as I must with lacquer or polyester, though CA flashes off very quickly), it makes for an impressive finish. The advantage it has over any other finish is cure time. It cures NOW! No need for UV lights (poly), let alone months of curing (NCL). Additionally, CA has a wicking quality, whereby it penetrates the fibers of the wood (it doesn't just float on top). It is harder than the wood, and adds a vitreous (glass-like) quality to the sound. It goes on stupidly thin. It is perfectly clear (no yellow hue), and it polishes to a shine just like everything else.

I use NCL on guitars for customers who insist on lacquer. I French Polish Shellac showpieces or guitars for customers who request it (by the way, Tom, I have not experienced the fragility / lack of durability argument against Shellac. It is not NCL, but it is pretty tough. Of course, I would not suggest it for those in high aerosolized alcohol environments. ;~}). And I use CA on everything else.

 

[RBSinTo]

Shellac is a beautiful finish. One of the prettiest. And easy to work. But fragile and not terribly durable. Same with French Polished finishes (shellac based). But the whole point is to protect the wood from the elements and also from the "schmutz" of life. Even oil based finishes provide some protection but oil is heavy and going into the wood thus changing it's characteristics. Poly is a super durable finish and now that it's been formulated for musical instruments so that it isn't so thick and restrictive, provides a LOT of protection. Lacquer is fast, easy to work, dries relatively quickly and is repairable to spot refinish as it is it's own solvent. It melts into itself.

Life is dirty, and wood is porous and if it's not protected will stain, and degrade while it absorbs the filth of life. Someone drops a Screwdriver (drink, not tool) near your guitar on a stand. Alcohol will damage most finishes, especially shellac (alcohol is the base of shellac) and orange juice will stain. Sweat will stain. Everything will stain. I think for what's lost in sound reproduction (minimal) the protection it provides makes it mandatory. Plus people want their guitars to look beautiful and if they're stained, they don't want stain coming off on their skin and clothes.

Unless there is some magical new finish that floats above the wood like a force field (requiring energy) but allows the wood to breathe and such, I think current finishes are just fine. Plus, since wood is so porous and absorbs moisture and expands and contracts it's better for the glued and joined pieces to have their absorption limited at least a bit, otherwise the joints would fail.

This is what I've come up with to answer your question.

Tom,
I appreciate your long and thoughtful reply, and was especially impressed with your use of the scientific term "schmutz", which is not often heard outside of high-powered research facilities and university laboratories.
Obviously a Sci-guy.
RBSinTo

 

[tommym]

.....whenever or not the bubble wrap will eat at the finish or not.

Other things that can damage a finish are batteries that come loose during shipping, and also odd and end items stored in the guitar case storage nook (if you have one) that somehow work their way out of the storage nook during shipping. I remove all this stuff before shipping my guitars.

Tommy

 

[kostask]

in general, any vinyl will out gas, and will eat into nitro finishes. So will other types of plastic, but not all plastics will. Bubble pack is two sheets of plastic formed with semi-circles to contain the air, forming the bubbles. If you do use bubble pack, you are taking a risk. There is NO guarantee that the bubble pack you are using is one of the safe ones. To be completely sure of no finish damage on a nitro finished guitar, don't put bubble pack directly onto the finish, as simple as that.

If the guitar is finished in a poly finish of some sort, you should be safe.

 

[Guildedagain]

Nitrocellulose fiber finishes - wood - breathe to let the wood underneath age, and as the finish crystalizes over the decades, it has been thought to enhance the tonal qualities of these guitars, both acoustics and electrics alike.

As the finish hardens and cracks - crazing - the surface tension of the finish lessens, quite possibly letting the wood vibrate a little better.

 

[kostask]

i know its popular on the internet to say "Nitrocellulose fiber finishes - wood - breathe", but wood doesn't breathe, at least not after the tree has been cut down. Nitrocellulose lacquer doesn't breathe, either. Saying that nitrocellulose lacquer or wood used in guitars breathes is like saying a block of steel, or a brick, breathes. They don't; in all cases, these are inert materials. Wood will dry out, but that is a moisture loss, and the lignins in it may redistribute themselves over time, but that is not breathing, they are strictly chemical processes. Same goes with nitrocellulose lacquer crystalizing over time, it is a function of the outgassing of the solvents in the lacquer, again a straight chemical process.

 

[walrus]

Blame the Beatles:

"In early ’68, The Beatles headed to Rishikesh, India, to study transcendental meditation with The Maharishi and friends, including Donovan Leitch. There, Donovan convinced the trio to sand the finish off their instruments, telling them how a guitar sounds better without a heavy finish. After returning to London, during sessions for the self-titled “white album,” Lennon and Harrison sanded their Casinos. Lennon primarily played his newly stripped Casino for the sessions. Harrison said that once they’d removed the finish, they became much better guitars. “I think that works on a lot of guitars,” he explained. “If you take the paint and varnish off and get the bare wood, it seems to sort of breathe.” With the completion of the white album, promo clips were filmed for the single “Revolution”/“Hey Jude.” The clips showed Lennon using his natural Casino."

walrus

 

[Christopher Cozad]

I had never heard that story, walrus. How interesting.

For many (most?) custom builders anymore, the last step in adjusting / tweaking / tuning the soundboard is sanding. Of course, this serves to prepare the wood for any finish that would be applied. But there is another purpose. Using either frequency, a lightweight material such as tea leaves and Chladni patterns - and/or - measuring deflection in the bridge area - and/or - rapping the board like a drum (mostly in the lower bout, below the bridge) until the target tone is achieved, the board is sanded toward the rims to remove stiffness. Having invested the time, earlier, in wood selection and careful bracing, this last step is necessary to create a so-called responsive top.

My guess is that by sanding off the finish on their instruments these daring and adventurous souls took a little bit of wood with it, thereby lightening the soundboard. Go too far and bad things can happen. But go just far enough and an otherwise hum-drum sounding instrument suddenly improves. With or without finish.

 

[cutrofiano]

Stradivarius wasn't concerned about the effects of various man-made organic compounds on the finish...

How do you know?

 

[cutrofiano]

George Harrison: "If you take the paint and varnish off and get the bare wood, it seems to sort of breathe.”

Everything they declared in these times was 100 % true and scientifically approved though hallucinogenic substances might have helped for some truths to show

 

[RBSinTo]

How do you know?

Because virtually none of them existed at the time.
RBSinTo

 

[cutrofiano]

Because virtually none of them existed at the time.

Are we talking about "man-made organic compounds" such as (sweat +) perfume?
Is 1.500 years b.c. long enough?
Makes 3.000 years before Stradivari (1648 - 1737 a.c.) even had started making string instruments.

 

[RBSinTo]

Are we talking about "man-made organic compounds" such as (sweat +) perfume?
Is 1.500 years b.c. long enough?
Makes 3.000 years before Stradivari (1648 - 1737 a.c.) even had started making string instruments.

You are correct, but I was thinking more of all the modern-day commercially produced compounds such as the hydrocarbons that make up bubble-wrap, deodorants, and the like that can mar the finishes on today's instruments, and weren't a problem that Stradivari ever imagined.
RBSinTo