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Hello to all

I Just received the Winter 2008 GAL magazine. It features a very interesting article on Manuel Velazquez. The article made me scratch my scalp in a few places. Here are some peculiar things:

-On the cover, we see a photo of either him, or probably his son, sanding a top with what seems to be either 60 or 80 grit sandpaper. It looks too coarse to be 100 grit. The guitar is obviously in the final sanding stage, by the look of it. Does anyone here ever use sandpaper this rough on a guitar top at this stage? It seems to me that using 80 grit would then require at least two or three other stages of either 100, 120, 150, 180, 220 or 280 (I personnally go to 320 grit on final sanding) before applying the varnish. In order to remove all scratches, this would mean removing a significant thickness of wood from the top (probably around .5mm, maybe even more), which seems pretty odd to me at this stage. Any thoughts on that?

-The Velazquezes mention their preference of using an oil varnish as a finish (Pratt and Lambert #38). They apply it by paint (and by the look of it on the pictures of page 12, they apply pretty thick coats of it), using between 4 to 6 coats and waiting at least 24 hours between coats. They sand using 320 grit before each new coat and give a final polish by wet sanding from 800 to 2000, followed by pumice and rottenstone. This method leaves me with the following questions:

a. can a fairly thick coat of an oil type varnish really cure hard enough in 24 hours to be sanded effectively?
b. how tricky is it to wet sand an oil based varnish of that type? Can you use water or must you use some sort of oil for this process?
c. They don't mention anything about pore filling, so I am not sure if they use any or if they do, what kind of pore filler they do use. I am just wondering if an oil varnish such as the one they mention would be compatible with a synthetic filler like Z-pozy or even a waterbased filler.
d. my experience with using oil varnishes on the tops is that it tends to dampen the highs, making the sound a little darker (at least on a classical guitar). What do you guys think?
e. About using pumice and rottenstone as a final polishing stage (with oil as a lubricant): do you rub it in circles, French Polish style or in long unidirectional stroke with the grain? Do you have to spirit off the leftover oil or just wipe it off with a cloth?

Velzquez says he doesn't care much about the look of the finish, that he only cares about the sound (a comment which triggered laughter and applause from the audience). Although this is a very noble approach, I doubt many luthiers can afford to go that route. All conventions that I have attended have shown me that the consumers care a very great deal about the look of the finish, and most luthiers I know spend a lot of energy on it (despite what a lot of them say). Taking this casual approach is very courageous, but in reality I suspect that only very well established luthiers can do that successfully. I sure still have a few hundred guitars to sell before I muster the guts to follow that lead...

Looking forward to your comments and input.

Cheers

Pat

I do not know what grit he's using on the cover pic, but it sure is garnet sandpaper. 150 or 220?
Oil varnish cures by polymerisation, not evaporation, and for most short-oil varnishes 24 hours is plenty (at regular temp and RH). That being said, I've never used Pratt&Lambert #38, but I do not think it would be that different from Behlen's Rockhard.
Dry sanding produces a fine white dust, very easy to sand. Wet sanding is as easy as with any cured finish, I add a tiny drop or dishwashing soap in a water container.
They brush it, I do not think they can apply it very thick in any case, they'd get runs and spoil the work, especially on the slotted peghead. If you get .0005" per coat, you're very good. Obviously theirs is a very thin finish.
Maybe they use a traditional oil based pore filler? Otherwise with patience oil varnish can fill the pores, it shrinks very little, but I assume at least a dozen coats are needed on a rosewood with medium pores.
It's not the first time I read the tale about oil varnish dampening the highs on a top. I do not know where the story comes from, nor if originally there was confusion with an oil finish (like Danish oil, tung oil, linseed oil etc.), and not varnish.
I've finished a few guitars with the varnish directly on the spruce, and a couple with Waterlox, a long oil varnish/sealer (thus softer) under Rockhard. Those guitars definitely do not lack in highs, quite the contrary, nor could I detect a sonic difference with other builds where I used a shellac sealer.
Varnish hardens with time, and pretty quickly, and does not remain soft like oil finishes.
I can't say for pumice and rottenstone polishing direction… How would it be different than wet sanding or polishing? Go round, figure-8, whatever, and always finish along the grain.
I'd take what he says (not caring) with a grain of salt… Maybe he's aiming at a kind of matte finish, not too glossy? With oil varnish and their method that wouldn't surprise me. And it can look gorgeous.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

The last new Manuel Velazquez that I had a chance to look at closely was in May of last year ('08).
It did not have what I would consider to be a lovely finish. There were areas that exhibited a lack of attention, especially the edge of the fret board over the top which had a rather gloppy looking accumulation of finish.
The guitar over all was aesthetically very nice, and sounded lovely.
I think the original poster has it right in that Velazquez is so famous that buyers (at $22,000. for this one) are willing to overlook this sort of thing.

www.guitarsbydavidlaplante.com

Hey guys

I am not an expert on oil varnishes and my experience with it is with tung oil, not an oil varnish as the ones mentionned. My impression is that the oil seeps fairly deep into the wood (especially the top), making is a little softer while it fully cures (in my case, that was a matter of months and years. Maybe I applied too much...). I have gone to French Polished shellac since 2005 for tops and either the same or a waterborne finish for the rest of the guitar.

That is definitly Garnet sandpaper, which I find too rough and uneven. I have switched to Carborendum (Aluminium Oxide Resin) paper a few years ago, with excellent results. It is much more even, leaves fewer deep grooves and doesn't load up as quick. I find that I have cut down sanding time a lot by using it instead of the Garnet kind.

I would understand the possible sloppy finish by Manuel (he is over 80 after all), but since his son is also involved in the process, then it is a bit puzzling. Maybe the $22 000 model is guarrantied to be made by Manuel entirely, then it would make sense. If his son also contributes, then allowing less than perfect guitars to leave the shop may damage his reputation after his father retires. Perhaps there is more to the story but then again, I don't know the specifics of the situation

Anyways, thanks for the feedback!

Pat

I agree -that paper looks like 80 grit !

BUT -he may have been asked by the author to look like your working ;or be doing something on a guitar!
For a photo !!!

That man has earned his way as a maker !
He's old school -and I love those makers !
They use their touch & ears to make guitars !

mike

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Mike Collins

The information about the damping of oil varnishes is based on research published by Martin Schleske in the 'Journal' of the Catgut Acostical Society, in Nov. '98. He very carefully (he's a rated Master in the German violin maker's guild, and also has a PhD in physics) tested a lot of finishes, and found that any finish containing a drying oil had a higher damping factor than either shellac or nitrocellulose lacquer. How high depended on the proportion of oil to resin, and, of course, on how deeply it penetrated and how much you used. A 'rubbing' or 'short oil' varnish, like 'Rockhard', is probably only about 1/3 oil, and dries too fast to penetrate deeply, so the added damping as compared with shellac is probably minimal. It does go on a bit thicker than FP, though. If you notice a difference in the sound with oil varnish, Pat, then you might want to FP the top and do the rest with the varnish. Rockhard sure is tougher than FP! It also looks nicer on dark woods, IMO.

For myself, I care much more about the sound than the finish, too. However, as I tell my students when they ask me about cosmetic points, you have to take that stuff up with the customer. It seems to me that before the Japanese started to ship shiny guitars here in the 60s the standards of finsh weren't so high. Now the customers expect that 'Lexus look', and you've got to at least try to get it. It's fairly easy if you can load on a lot of something hard, like nitro, but that tends to eat sound. Getting a really slick finish with .003" of shellac in French polishing, or .005" of oil varnish, is another matter, especially if they insist that the pores be perfectly filled. I sometimes wonder if the buyers realize just how much they're paying for that perfect finish: I think it's about 1/3 of the man hours per guitar.

Anyway, Valasquez learned his trade before the Invasion of the Yamahas, and, as has been said, can sell guitars on his reputation without worrying as much about the fine points of appearance.

As I mentionned, the dampening of high frequencies is something I noticed when I switched from tung oil to FP shellac as a finish a few years ago. It was something I realized fully as an afterthough since the switch was made purely for esthetic reasons...

I am sticking to FP for the tops (for now anyways) but moving towards a waterborne finish for the rest of the guitar.

I am pretty happy with the combination of Z-Poxy (2 to 4 coats, depending on how deep the pores are) and Target Coating Oxford Ultima lacquer that I apply with a combination of brushing and "French Polishing" (Yep, it does work. I got a method for doing it in an article on Waterborne finishes in GAL). I have been working at it for the last 3 or 4 guitars and the results are very satisfactory. I am now "pushing" my customers to chose that over an entirely FP`ed guitar.

Thanks guys

Pat

Hey Pat, I was at that presentation and both Manual (through his son) and his son did say that they make guitars, after they make the guitar, the finish is only there for a bit of protection and because people want it, but it certainly appeared that it was not the part of the process where they spent any time or detail. Also, I think the high end classical circle is different than the steelstring circle. The classical guys really focus on the sound and feel of the instrument and will overlook the apperance if the other two are where they need to be. Yes, I am sure that there are many that can address all 3 areas, sound, feel AND looks but the Velazquez's were pretty up front that that don't spend a lot of time on appearance, no apologises either (not that any were sought!)

Shane

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Canada

As pointed out before an oil finish like the tung oil you mention is very different from a short-oil varnish like Rockhard (or P&L#38, which I assume is a short-oil varnish).
I imagine tung oil or linseed oil can penetrate fairly deeply into a soft spruce top and thus dampen the high frequencies (until it hardens a few years later maybe…).
As Alan points out the finish part is a lot of work, probably 50% of the time I spend building a guitar, sometimes more. It is also a fairly constant source of surprises and frustration…
My varnish finish is usually .004" thick, I personally do not hear a difference between nitro, shellac or varnish at that thickness.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I was at that presentation also, what a treat, and an inspiration to me.
I was one of a few who hung around after, gathering at the stage to talk. The concert guitarist gave Manuel a personal recital on 6 of his guitars, from the 50's into the 90's. I have read the article in AL over and over to remember the experience.
I do not build the classical, but I love that man and his work.
I am personally working toward the day when my guitars are valued for the fit, tone and playability, with scant attention to the thickness of the shine. I actively choose my customers with this in mind. Thus, I offer a rudimentary french polish shellac finish!

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Doesn't he say that the tops are FP most of the times because customers don't like to wait for the dry time? I think he also said that he uses linseed oil instead of olive oil which is the Spanish method. I think Manuel is in his 90's if I did the math right from reading and old artical about him.

I wondered what kind of finish he used. Any ideas on how to freshen it up a bit?

I think he was saying he liked the P&L 38 varnish because it was based on linseed oil, if I read it correctly.

One of my favorite quotes of his, if I may misquote: speaking of top wood "The tone is in the wood, be sure to leave some wood for tone."

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Laurent Brondel wrote:
"I imagine tung oil or linseed oil can penetrate fairly deeply into a soft spruce top and thus dampen the high frequencies (until it hardens a few years later maybe…)."

The German violin makers often flood the surface of a completed fiddle with linseed oil, and hang it for a year to develop a patina. The oil will often penetrate completely through the ribs; a millimeter or a little more of soft maple. The low molecular weight fractions go in the furthest, of course, and it strikes me that tung might have a fairly low molecular weight, judging by the low viscosity. It doesn't surprise me at all that you noted a difference between tung oil and shellac. Schleske found that shellac actually has lower damping than cross grain spruce strips, so a coat of shellac makes them 'better'.

Clay, is that yours?
I hope you aren't serious about "freshening up" the finish. If you do anything but clean or polish with a cloth, you will do serious damage to the value.

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Hi David,
I have had that guitar for a few decades, one of the few I hung on to. The finish has severely alligatored as you can see, and I wonder if there is a way to safely reamalgamate it without stripping and redoing it. It would be a pretty guitar if it had a smooth finish. But if I can't do it simply and safely I'll let it be. It still sounds good.
That is a good quote to keep in mind when building.

I've had many makers guitars in my shop over the years.
Every look at
Mellinium ?Barnabe?Hannabach ??
Finish is important to keep the woods from moisture-sweat -etc..
These great makers chose NOTto load the wood with weight !

The modern dip in plastic look is to much !!

We just stripped a 85 Ramirez A1 and french polished it-the thing came alive !!!!
The old finish weighted a ton !!
It seems like the bling affect is more important than the substance
of the sound now adays!
Mike

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Mike Collins

I did some french polish repair to a Bernabe flemenco with fingernail marks. I used to read about Paulino Bernabe, and it was the first one I ever played. It was dead as a doornail, but it had the thickest FP finish I ever saw. I don't know how he built it up that much.

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Dave
I 've seen many Bernabes over the last 30 years
And many other french polished guitars-along with the lacquer & urethane bunch !!
The heavy application of finish may sell looks; but does nothing for tone/sound of a instrument!
Make guitars ;not furniture !!!


mike

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Mike Collins