As mentioned elsewhere, in my old age I find myself puzzled by the notion of a high gloss lacquer finish, which is odd, because it was actually the first thing I learned how to do after I became Michael Millard’s first apprentice at Froggy Bottom Guitars in 1974, and I learned it very thoroughly.

A year earlier I had purchased Michael’s first 12-string guitar, which was such an addictive instrument that I took it with me everywhere, literally, except to the bathroom and to bed. As I was roughing it a bit and hitchhiking quite a lot, that 12-string took quite a beating during that time. I think Michael thought it would be a good way to calm me down and focus if my first guitar work was to refinish my own guitar, perfectly. And that is what I did.

The original nitrocellulose lacquer had been thoroughly crazed from many very cold nights, and so to start, it all had to be stripped off down to bare wood, beautiful bare Brazilian rosewood less than two millimeters thick to be precise. The tool I was told to use was a scraper – a file card-sized rectangle of slightly flexible tool steel I had never seen before. I won’t go here into how a scraper was sharpened, which was quite a learning experience in its own right, but proper sharpening yielded a microscopic, razor-sharp, curled-over cutting blade running the length of the scraper’s edge. You held it with both hands at about a forty-five degree angle and bent it slightly away from you with your thumbs, and pushed it hard across the surface over and over again, changing the direction of thrust with each pass, the tiny long cutting edge actually raising little curls of microscopically thin lacquer and wood along its length.

But the scraper was not a happy, friendly tool – it was a sharp-edged, sharp-cornered piece of tool steel that seemed to always be baring its teeth at you, and lazy because it had to be re-sharpened after every thirty seconds or so of use. You actually scraped with a stack of scrapers, using one after the other until they were all dull, and then you would re-sharpen the whole stack and get back to work. If your mind wandered and you slipped, the scraper could do instantaneous damage to your hand, your guitar, or both. Cuts to your hands healed OK on their own, but scratches, gouges and cuts on that beautiful and very thin wood all had to be scraped down to flat, so you quickly learned to be very careful, marveling that you hadn’t yet scraped all the way through anywhere.

Once down to bare wood, every surface was sanded with 220 sandpaper, then 320 sandpaper, whose job it was to make disappear all of the fine scratch pattern left by the 220. After a final inspection to make sure every square millimeter of every surface, large and small was perfectly sanded, the guitar was given a quick rub-down with lacquer thinner and allowed to dry.

The new finish started with a “wash coat” of 50-50 lacquer and thinner being applied in a dedicated “spray booth”.  The spray booth consisted of a small room with a large Fiberglas air filter in the door and a large exhaust fan on the far wall. Spraying each coat evenly on all those complex surfaces required holding the heavy spray gun in one hand and the heavy guitar in the other, both being carefully and slowly manipulated in a kind of ballet to maintain standoff, angle and rate for each coat, and not spray yourself in the face. The easiest way to get in serious trouble was to knock politely on the spray booth’s door when someone was inside in mid-spray, and the fiberglass air filter would wake up and say hello by releasing a load of sawdust into the air stream.

After the fifty-fifty wash coat, the coats that followed were only partially cut with thinner.  The first went on just an hour or two after the wash coat, but subsequent coats were allowed to dry for a full day, because the lacquer was only five percent clear solids, and the rest had to evaporate off before the next coat. Before each coat, you carefully inspected every bit of the guitar, looking for any specks that had landed in the previous coat, and you sanded them out very gently with some 320 paper. It took about ten coats to get up to even thickness all over the instrument, and then it was left hanging for a week or two for the lacquer to really harden. After that, the work of creating the new perfect surface commenced.

So how did you get to shiny? And just what made a shiny surface shiny, anyway? The answer is actually quite beautiful: it has to do with the interplay of the wave nature of light with wavelength–scale surface features on the guitar. One of the characteristics of all wave phenomena, both light and sound, is that an object will only interact with waves equal to or larger than the object itself. A wavelength larger than an object just goes right by it like it wasn’t there. Some examples - A bat needs extremely high frequency sound with its very short wavelengths to “see” insect prey. To optimize the acoustics of some musical performance halls, sound reflecting panels are hung here and there in different sizes, their sizes determining what range of frequencies of sound each will reflect.

Because a passing light wave will not interact with something smaller, a typical dull knife edge, whose width is larger than the wavelength of light, will reflect light while a freshly sharpened knife edge, whose width is now less than light’s wavelength, will not. The size boundary between sharp and dull knife edges just happens to bracket the range of wavelengths of light we see.

To create a mirror surface, the dense, parallel scratch pattern covering the surface must simply have individual scratch dimensions smaller than the wavelength of light.  A light wavelength encountering such a fine-featured surface doesn’t even know the fine features are there, and reflects off the overall surface geometry. Aha! Mirror!  How big is the wavelength of light we see? Across the edge of a typical page in a book there are about 100 wavelengths.

The creation of a gloss surface thus boils down to simply making the surface sub-wavelength smooth.  You start with 320 paper on all surfaces, being careful not to sand through anywhere, though actually you do now and then, and you have to start over on those spots. Once safely through 320, you use 400 paper to erase all traces of the 320, then 600 to erase the 400s, 800 to get rid of the 600s, etc. Above about 800-grit, different levels of buffing compound can be used interchangeably with finer paper grits. The surface starts to break into a real smily shine around 4000-grit. 4000-grit corresponds to about six wavelengths, but that is the grit on the sandpaper, while the array of surface scratches created by the 4000 grit rubbing this way and that start to fall below the wavelength limit. If you have the patience and stamina to sand every square inch of your guitar down to 12,000 grit, the surface will be truly like glass, and adding a polish cannot make it more glossy. What a wax finish does is to fill in the valleys between the larger-than-wavelength surface scratches of a dull finish, so that the little scratch mountain peaks poking up through the wax glaciers surrounding them are smaller than the wavelength limit, and you have gloss! At least temporarily, which is all a used-car salesman needs.

So there you have it. What is glossy and how to make it. But the question remains – why do we seek it? It is a generally recognized fact that even if you don’t like glossy finishes on your guitars, you better make at least the face glossy if you want it to compete on a music store’s wall. Is this attraction to shiny cultural, perhaps because we were brought up to associate shiny with good hygiene, like cleaning the dishes, or is it something deeper? There was nothing gloss shiny in our evolutionary past that I can think of besides still water in a pond, or the glint of an eye close-up.

Getting back to the picture, it was a wonderful revelation to learn at some point that the cleanest air there is for spraying lacquer is outside air, no filter or fan required.