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Sop it seems the past few weeks I keep having the same conversation with different people about nitro finishes.... So I wrote a piece for my blog about it to help others understand why nitro is less and less of a quality option for guitars. Hope you enjoy the read.https://howardguitars.blogspot.com/2018 ... r-era.html

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I enjoyed reading that Brian. Thank you.

I've always been limited to brushing-on finishes and the fact I could never use NL, as a beginner made me think my guitars wouldn't be as good because of it. If this info was around when I started I could have saved myself from fretting over it.

Cheers,
Glenn.

Thanks Brian, what a great article.

I'm super new to the world of wood finishing, but have settled into experimenting and learning with water borne finishes because it seemed that while NL finishes are still available where I am, that would likely not be the case forever. So I might as well learn with something that would be around for a while.

I was wondering if you could give any advice about getting into UV cured finishes. It seems like it would require a substantial investment, although the luthier I took a repair course from last summer told a story about a luthier in Turkey he met who hung his instruments in a south facing window to cure his finishes. So perhaps there are work arounds?

If there is an end to nitrocellulose lacquer, it seems to me that it might be because of VOC concerns and an EPA or state ban by those more authoritarian-leaning governments, rather than any broad dissatisfaction with the material. A quick peek at UMGF and other enthusiast sites serves as a quick reminder that despite formula differences over the years, nitro is still perceived as a premium finish, and - more importantly - the finish used on the iconic Martin and Gibson guitars that have such an irrational hold on many of our customers.

I much prefer the EnduroVar finish we use on some necks and bodies, despite it's horrible handling qualities versus lacquer, but we still have customers that insist on at least the body being nitro-finished. While I would like to report that we have a line out the door of customers insisting on gluten-free, compassionately-raised, tofu-based finishes on their instruments, the count remains in the very low single digits - ok, zero, if you insist on a degree of accuracy - for those demanding something different. For every customer wandering in and demanding an end to lacquer checking, etc., we have a dozen others asking us to strip off the poly in favor of nitro (we don't).

The arguments against nitro and for other finishes are a good summary of the arguments floated over the last 10-15 years. Add to them the instances of body chemistry incompatibility, as well as the the tendency of nitro to cold check, hot-print, and fail in thoroughly impressive ways through either excessive or insufficient plasticizer packages. Also add the issues with sensitivity seen in finishers and the sensitivity of neighbors to the stink of lacquer...a surprising number of alternative finish evangelists such as Mr. Greven seem to have arrived there via either an inability to spray the stuff in tightly-packed neighborhoods or health issues associated with nitro use. There appears to be nothing like a few days in hospital due to a severe reaction to nitro to create a sincere interest in and enthusiasm for alternative finishes.

I would question whether the majority of hard-drying varnishes are 'natural', and certainly not any of the alkyd (aka synthetic polyester), modified acrylic, or phenolic resin-based products which seen to dominate the short-oil varnish market. Even where the finish may be fairly described as natural, oil drying agents may be present that are quite toxic until fully bound, so equating 'natural' with less toxic might be a stretch.

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For the times they are a changin'

- Bob Dylan

Brian,
Excellent article!!! I've felt the same way about nitro for a number of years. When I started building I went with water based mainly to avoid the checking and effects of common solvents on the finish. I do like many aspects of water based but I have since drifted to Cardinal Luthierlac. I frequently look at other, relatively newer finishes, but the only one that seems like a really good alternative is the UV cured stuff. But when I look at the cost of the UV wand, not to mention the safety equipment, I alway settle on doing a few more with nitro. Any suggestions on a finish I should consider would be greatly appreciated.

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Joe Beaver
Maker of Sawdust

I am very much on the fence in regards to finish affecting tone.

I don't do a lot of gloss these days, but my experience has shown me that the differences in finish applied to my own work aren't subtle at all but very, very dramatic. Night and day, apples oranges, black and white.

What I'm not sure of is whether it's the material itself, or the final film thickness I'm hearing/feeling.

Unfortunately my local options haven't panned out so I've been shipping to USA which costs me about a grand per guitar so I can't really afford to do a lot of experiments.

I would love nothing more than to build a run of guitars and have them all finished by the same person with different finishes. If you were still taking in work I would do just that.

I was well pleased with the sound of the guitar you finished for me in conversion varnish compared to other gloss finishes I've had done, but it also came out at 3.5 which is dynamite IMO.

So again, material or final film thickness?

I noticed you're in Vancouver, I'm on the island.

Have you tried Vancouver Guitar Finishing? I haven't sent them anything, but I did talk to the guys about a repair I needed help with and they seemed pretty knowledgeable.

Ed, I've sprayed conversion varnish a bunch of times on stairs and millwork, the more high end stained stuff. Never considered
using it on a guitar but maybe it's just the ticket for low sheen purposes. Certainly durable enough. You only shoot two or three
coats max so the film thickness shouldn't ever become an issue. I bet there's people locally who build and spray furniture etc. with this,
who would do a dandy job on your gits.
If it was me in your shoes I'd be trying to find a way to do it in house, money in pocket. Just sayin.

Since I started the Halcyon brand, I've had orders for only four of the Tinkers, so 250+ against four means that setting up to do it myself isn't very practical. Though at some point I will learn to FP...

Yes there is an equipment investment just like anything else we do. Spraying finishes in general requires an investment. You need a compressor, guns, regulator, filter.... UV curing is in addition to those. While I have heard of the sun cured material I have no experience with it. My thoughts on it are that the process is slow and would be open to contaminate from dirt while sitting and curing in the sun for hours. From what I have read you would be much better with a catalyzed coating than this IMHO. Any area that doesn't get enough UV energy will not completely cure and cause problems.

A small pro quality handheld ballast driven UV emiter and proper safety gear will cost $1000-$1500. Figure another $500 for your first materials order. You can save money by using conventional welding safety gear like an auto darkening helmet with a shade adjustment, gloves etc if you already have them. There is a learning curve too, spraying is different due to the almost complete lack of solvents and curing takes a bit to learn to do correctly without missing spots. But once you have the system down it is the quickest , easiest thing I have ever done to finish wood.

I do not ever see this technology being widely available or used by the general public and as such do not see the price dropping very quickly in the future. The auto re-finish business has already decided that waterborne is their future and most cabinet shops will likely transition that way because it requires no additional equipment investment and minimal re-training to use. But as I point out often, we are different than the rest of the wood finish world in that we want a perfect mirror finish which is something that the UV stuff excels at.

So is it right for you?, that is the real question and will likely involve a cost/benefit analysis. Yes the start up is a bit of an investment and yes the materials are more expensive than lacquer but not really any more than 2K urethane when you consider the complete system with reducers etc.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks for your reflections, Brian. While I have never bought the "save the earth" stuff peddled for years to us, I do agree with most of your conclusions. It's been years since I shot nitro or acrylic lacquer, and I loved the way it looked and performed on the instruments I built. Today, I must agree with you about using less of it simply because of the time involved waiting for outgassing and drying to occur. Time is money, and the luthiery craft is not the only industry to make decisions about such things. We have to get with the times, and use quicker finishes - and gratefully, there are many for us to choose from.

Here's an example from automotive history on the same subject. The reason Henry Ford only offered black on Model T's a hundred years ago was because black dried faster! It took longer to paint a car with then state of the art Japan Black Varnish than it took to build the whole thing (they still used brushes back then), using black literally saved WEEKS of time in the paint department. Time was money even back then, and Henry was smart enough to become the richest man in the world because of his decisions.

Today - if we are smart - we make those same decisions.

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"Act your age, not your shoe size" - Prince

I'll shoot nitro until they pry the (spray) gun from my cold dead hands!
Just Kidding! I've been looking into some other finishes, but until I find one that is relatively easy to apply , as cost effective, and looks as good I will stick with nitro - assuming it is available. As an amateur with no pressure to "giter done!" the extra wait time is no big deal.

Interesting blog post, Brian. I agree with much of what you stated about nitro's shortcomings but I don't come to the same conclusion as you do of the inevitability of 100% solids, UV cure finishes for the small builder. If you want to make 300 guitars per day then yes, that is the only way to go.
One of your statements stood out to me and I respectfully disagree:

Varnish and shellac are natural and NL was a vast improvement over those.

I have examined several original Torres guitars and an Enrique Garcia, all with the original finish. The finish on all looked fantastic. They had all been played but the finish looked really great for having 100 years of playing logged on them. A similar finish can be seen on early Martins and many of the Chicago-built guitars like Lyon and Healy. Again, the original finishes look really great, all things considered. If you compare nitro finishes from the 30s to these finishes there is no comparison. All of the guitars I mentioned had some type of shellac finish, either straight shellac or an amalgam of shellac and other resins.
I don't know enough about classical Italian violins as to how much of the original varnish has survived on violin family instruments for 350+ years but my impression is that a lot of the original varnish remains.
So, I can't get behind the statement that nitro was a vast improvement.
I believe some aspect of finishing guitars with shellac has been lost. Either it is the way shellac is processed today or the mixture of gums that was incorporated, or a combination of both. The fact is that finishing with shellac is the nearly perfect method for a small hand builder. No special equipment is necessary, no explosion proof spray booth or supplied-air respirator, no buffing station or buffing compounds, no UV lights or extended cure times, no issues with adhesion and no witness lines. Oh yeah, it sounds better too.
So rather than gear up with all the aforementioned hardware and the associated headaches (both literal and figurative) my focus is to try to figure out how the finish on late 19th to early 20th century guitars manages to look so good after all these years.

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Stay with the happy people.
--Reynolds Large

Nitro is a snare, and always has been. It's chemically unstable, and puts out nitric acid as it breaks down, which harms everything around it. It was the first spray finish used on cars, and was part of the reason Chevy overtook Ford, but they only stuck with it for a few years, due to the breakdown and yellowing, which are accelerated by sunlight.

Several years ago there was an exhibition of guitars as art in the Museum of Fine Arts in Boston. It was easy to see when Martin switched from using shelac and varnish to nitro: the guitars after the switch looked much worse. One instrument in the exhibit was a Stromberg archtop, all tricked out in celluloid trim and a heavy nitro finish. The black celluloid head veneer looked as though it had been torched. All of the binding was cracked every couple of inches and starting to fall off. The checks in the thick lacquer were starting to pull cracks in the wood. That one never made it into the catalog of the show

Most of the oil-resin top varnish on Strad's violins has been worn off over the years. Given the difficulty of quality control in varnish making, what's left is a mixed bag: some is very nice and some is...not. The 'ground coat' that underlays the varnish, however, is generally in good shape. In fact, it wears like iron. Or maybe I should say glass.

One study, using an electron microscope, found that the ground usually consists of some sort of pumice, in small particles, bound together with a resin. They were unable to say what the resin was, but the 'rocks' were variable in composition. It looks as though they just used what they could get as the filler. Subsequent work showed that the physical attributes of the ground coat were consistent with a typical French polish fill, although there was one other method, called 'Rubio Rubble', that gave similar results.

When it's fresh shellac is soluble in alcohol and alkaline water solutions. This changes over time, as it cross links, and after about 75 years it becomes insoluble in anything. As a material it is about 2/3 as hard as nitro, but more flexible, and less chippy, thanks to the cross linking. AS French polish it goes on very thin, and .002" of even the hardest coating is not much protection against dings. Given that many people seem to have alkaline sweat it can wear off in a hurry. Nobody seems wiling to hang their guitar up for 75 years to allow the shellac to really cure..... It's possible that this is the 'secret' of Stradivari's ground coat, but it will be nearly impossible to 'prove' it, and many people would not accept it even if it were demonstrated.

There is no 'perfect' finish. All you can do is try to find one that does the things you need, and has drawbacks you can live with. For me it's oil-resin varnish. Yes, it's slow to cure, so it's hard to get that 'New Mercedes' look: it shrinks over time and allows the grain of the wood to show. OTOH, it should hold up longer than nitro, is more flexible and less chippy, and brings out the 'light' in the wood like no other finish does. I can brush it on and end up with a thinner coating than most other finishes, but it certainly is more labor intensive than spray finishes.

what a good write up on an old debate Donny

Suddenly I feel so old...
Fortunately, I did all my mandolins in Joseph Hammerl (JOHA) violin varnish, spirit over oil. They all checked like the old Gilson's, a difference in shrinkage between oil and spirit, but it was a necessity. Tonal qualities were far superior to lacquer, but the finish was soft, so used nitro for steel string guitars.

Same here. I’ve sanded off poly and reshot lacquer. I hate spraying, sanding, and polishing, but the end result is good.
I did my last build with tru-oil. I like it on that particular guitar.

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wah
Wah-wah-wah-wah
Wah

I have both nitro and poly on all of my guitars and will always prefer nitro. It feels awesome and tactile. It wears so beautifully, like art. I can't imagine a world without nitro. Germanium transistors. Vacuum tubes. Tape delay. Bucket-brigade delay. Hand-wound pickups. Manual transmission cars. Natural women.

OP has a preference and wants everyone else to abide to it.

...and razors plus a dab of antiperspirant...for when nature becomes a bit too natural to be bareable.

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For the times they are a changin'

- Bob Dylan

Old, undamaged shellac seems pretty bulletproof. I own a 1920s Hawaiian-made ukulele finished in shellac, and the finish is still in fine condition and very hard indeed.

The problem I see with shellac is that it's (a) slow to apply, and (b) fragile for the first years of its life. That's fine by me as a home builder, but if I were doing this commercially I'd not be able to justify the space and the time.

I'm currently brushing on thin coats of shellac, but can only do one coat per day otherwise I risk building up the finish too fast. That's not commercially viable. But for the home builder it's a good method because it's pretty environmentally friendly and requires minimal skills. Once I have built up the finish I'll just level it with wet sanding and then either buff it or apply a top coat of something less friendly like Tru-Oil.

The technique and formulas have been lost. I know a lot about original, natural finishes as well. Started out at a time when we still made our own varnish from scratch and I agree a PROPERLY done French polish is as beautiful and durable as anything (with proper care), but most do them poorly or completely wrong today. If you have more interest here is a link to a presentation I did on FP and shellac some time ago. https://howardguitars.blogspot.com/2015 ... l-way.html

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

the guitar market is indeed a funny place.

Some people will not buy a non nitro guitar. Others prefer French polish. Not to disagree with what your saying Brian you do have to decide what your market wants. My clientele insists on Nitro and that is what I have to do in order to sell .Again that is what I am known for. I have tried a few different finishes and I personally am not a fan of the poly finishes, the water finishes I am liking. I do like the conversion varnishes.
There comes a point to what the market wants and if the legalities on Nitro change. Some states it is illegal or just too difficult to obtain. FB are very labor intensive for sure but worth the effort to learn.

In the end it comes to what works best for you and your market. In some cases finding a good finish guy may be to your best interest. I can finish but do use pro finish guys as I don't have room for a spray booth anymore and with the solvents and VOC's and of course the insurance it made it economical for me to go with out sourcing finishes. I still do touch ups. Now I don't have to worry about cleaning the shop and over spray.
There is no doubt each finish has it own set of problems. Nitro was and is indeed a good production finish and was used early on for that reason. The health issues on this is a concern . Martin had a great spray booth that had a water wall and was safe enough that OSHA didn't require a mask. That has been swapped out by a robotic system and now no humans are in the booth during spray. The old finishes in many shops were a proprietary concoction and are an interesting subject on their own.
The new finishes are getting better are being repaired and that was a great advantage to nitro and shellac. A 100 year old finish is still repairable . Urethane don't have that luxury. Still it is a good discussion as there are many options out there.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Another way to put it, people are different and prefer stuff for reasons.

The first time I worked with nitro was maybe 5-6 years ago. It was an instant love affair. That's unusual for me because I typically hate the finishing phase.

If you asked me what, specifically, I loved about it, I don't think I could tell you. All I know is I loved the feeling I got using it. It felt pure, maybe natural, sort of being one with it. What I do know is that feeling is not because of what I heard from the nitro purists because I walked into this knowing only that nitro is what Fender uses. At least that's what I heard at the time.

Linda Manzer was interviewed in American Lutherie. In it she was asked about finishes she uses. She said she's still using precatalyzed nitro, having tried waterborne products over the years. Waterborne finishes freaked her out because of all the chemicals added to them. I'm kind of the same mindset. Pretty much everything you can buy on the market has something in it that's not good for you.

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Julie Moriarty
http://JulimorCreations.com

Would love a nitro contact # John...