Handmade from the finest select woods and materials

Acoustic Archtop Guitars

by Master Luthier


Tad R. Brown

Finishing



Crystalac Brite Tone Guitar Finishing Instructions


A fantastic alternative to nitrocellulose lacquer is Crystalac Brite Tone. It is a non-toxic waterborne urethane instrument finish that looks and sounds as good as traditional lacquer, without the toxic solvents and noxious fumes. Long term exposure to lacquer solvents is well known to have serious health consequences, and after so many years of noxious fumes, I was really seriously considering outsourcing the finishing process, until I gave Crystalac a try. But the real question is, yes it is non-toxic, but is it as good as lacquer? I can state unequivocally, yes!

Most waterborne products have a bad reputation, and deservedly so, because they are genuinely awful, but Crystalac is a notable exception. Brite Tone is the best waterborne guitar ‘lacquer’ that has ever been developed. It is crystal clear, dries hard, doesn’t blue, doesn’t fish-eye, doesn’t check, doesn’t hurt tone, and can be wet sanded without streaking or cracking. It has properties similar to lacquer in that each coat burns into the previous coat, shrinks while it dries, sounds great, and buffs to an exceptionally smooth high gloss, making the final polished finish indistinguishable from lacquer.

Brite Tone is technically a type of polyurethane, but not at all similar to the polyester resin that most people think of as ‘poly’. It is nowhere near as thick and bulletproof. More similar to lacquer in how thin the coats build and how scratch/dent resistant it is. That is to say, like lacquer, durability is adequate, and not nearly as super tough and deadening as polyester. Brite Tone, when applied in moderation, is tonally transparent, like lacquer.

Since there is very little in the way of advanced instructional info available, and because switching to a viable non-toxic finishing process has been such a game changer for me personally, I decided to write this article. The manufacturer’s recommended directions are a bit vague and oversimplified. When they say “fast building, high solids”, I take that to mean relative to lacquer, in that I end up spraying about the same amount of coats in the end, and the finishing process is essentially the same. This guide is not so much intended to be an intro to guitar finishing, as it is for those who are already familiar with finishing and maybe looking to get away from spraying lacquer.

For all it’s amazing qualities, there is a learning curve involved in switching from lacquer to Brite Tone. It is not as forgiving to spray as lacquer, and drips easier. The sweet spot is narrower. It’s all about good spray-gun technique, and laying down smooth thin coats.

I like the Apollo 7500 spray gun with a 0.8mm needle for its super fine atomization. Set the material flow knob low, opened only about 3/4 turn, with the fan control set about halfway. Spray in slow, even, consistent, vertical overlapping passes from about 6 inches away, while keeping a close eye on the flow-out. There should be just enough liquid material hitting the surface to flow out nicely without dripping. If you’re getting drips, move the gun faster and turn the flow knob down. Also be sure to have enough turbine pressure to spray full strength without needing to thin, about 7psi 130 cfm.

Cleaning up is really easy with just warm soapy water, and they also make a dedicated spray gun cleaner, vinegar-type solution for dissolving residue from other finishes.

Another plus is that Brite Tone is easier to sand than lacquer. No gummy pigtails, sands like a dream; cuts to clean white powder. Gold sandpaper works fantastic, and causes no fish-eye issues.

Crystalac recommends 2-4 hours between coats, but this can be tough as there are only so many hours of daylight. I’ve found 1 hour minimum between coats to be ok as long you’re in a normal temperature and humidity range (above 65 degrees, below 50% humidity) It dries to the touch in less than 15mins, but cures slower than lacquer, so 2 hours between coats is better. Blushing can occur in cool or humid weather, but does not need any special treatment to free up the trapped moisture, unlike like lacquer which often does. The blush will simply evaporate and disappear as it dries. Sunlight or a warm hair dryer can speed things up.


How to achieve a flat thin glass like professional finish:

Sand all bare wood to 220 and seal all porous surfaces with Crytalac Sanding Sealer and clear Wood Grain Filler.
1 coat sealer, apply wood grain filler with a card/scraper, dry 4 hours, block sand 400, 1 coat sealer.
Repeat till pores are completely filled and sealed, usually 2 sessions is adequate.

Note: for color coats on close pored woods such as spruce and maple, it’s better not to seal those surfaces, in order to allow greater dye penetration, but rosewoods absolutely need to be pore filled first.

Mask and spray color.

Pull tape and detail.

5 coats of Brite Tone 2 hours apart, dry overnight.

Carefully, lightly, cut down just the high points with 400 grit on a hard sanding block. Don’t attempt to sand flat and level yet, and do not go through into the color coat!

Blow off the dust and wipe down the surface with Crystalac Surface Conditioner to remove all reside and prep for the next coats.

5 more coats of 100% Brite Tone, 2 hours apart, dry overnight.

Block sand partially level with 400, leaving some pores and depressions here and there. Those will fill in during the 3rd session.

5 final perfect smooth coats of 100% Brite Tone.

Hang and allow to fully dry 10 days minimum, 2 to 3 weeks is better, or longer if you’ve got time.

Wet sand the entire instrument with 1500 grit on a hard block. Work small areas at a time with minimal water, wiping up with a soft clean microfiber towel frequently. Do not allow water to run into f-holes, sound holes, tuner holes, or any unsealed surfaces… Water can swell bare wood and crack the finish, but finished areas will be effectively sealed and waterproof. Now the surface should be completely flat with a satin sheen.

With a random orbit palm sander on low, gently wet polish the entire instrument with a 2000 grit Abralon pad backed by a soft interface. Don’t use too much water. The Abralon pad should be moist, but not dripping wet. It will need to be washed and wrung out several times as finish residue builds up.

Carefully inspect for any remaining 1500 grit scratches, and keep polishing with the Abralon pad till they’re gone. Now the finish should be completely smooth, with a low gloss sheen.

On to machine buffing. I use a 1HP 1725 RMP arbor with 12″ wheels. On one side, a hard canton wheel with pink Menzerna P-204 medium cut dry stick compound. The other side, a soft cotton wheel with Menzerna extra fine P-175.

This is the most dangerous part of the finishing process. As you should know, one slip could spell disaster. Be especially careful around edges, corners, f-holes, and soundholes. Light, controlled passes. Let the compound do the cutting, not too much pressure, and keep moving, don’t let the surface heat up. Also be sure to wear a dust mask and eye protection.

A beautiful high gloss finish should easily be achieved with the medium wheel buffing in alternating directions. Polishing the top around the f-holes is a bit trickier. Maneuver around, and be very careful not to catch an edge.

Wipe the entire instrument with a soft clean microfiber cloth and inspect for scratches. Any remaining scratches can be polished out with another trip back to the buffer. The surface should be glossy and nearly perfect looking, with just a slight texture from the wheel burnishing the surface.

A few more passes with the extra fine soft cotton wheel brings the finish up to an incredible ultra high gloss.

Final step, hand polish with a microfiber towel with Meguiars Ultimate liquid wax. This brings out the ultimate deep smooth glassy shine, and cleans up any remaining lint and compound dust. Also makes a great guitar polish for removing sweat and fingerprints.

In summary, anyone looking for a viable lacquer alternative, or looking to rid the shop of toxic chemicals should be taking a serious look at Cyrstalac Brite Tone. It is an excellent instrument finish that looks and sounds as good as traditional nitro lacquer, without the toxic solvents and associated health risks.

Cheers,

Tad R Brown