Machining wood versus hand planing for tonal quality

[Malcolm Schweizer]

Good day all,

I was just sitting here thinking about tonal qualities of wood- you know, the sort of thing most people think about early in the morning ;-). I have this amazing single piece of WRC that was cut in the early 70's (not by me) and is big enough for a single piece top for a classical guitar. It has over 30 growth rings per inch and rings like glass when you tap it. I have been waiting for the right moment, as well as for me to develop my skill, before building the "Tonemeister."

While thinking about tonal qualities of wood, I also was thinking about sharpening molding plane blades. (Stay with me here- this will come together.) I was thinking about how when sharpening on a machine, I have to worry about the heat generated, which we all know can change the metal's hardness. Then I thought about when you machine wood. It generates heat- enough to burn the wood if not careful. I started to wonder- could heat change (ever so slightly) the crystaline structure of the aged sap in the wood, thus changing the tonal qualities? I'm not talking huge changes here- I am talking concert guitar for a tone nerd who can hear silent dog whistles and tones other normal people can't hear. ;)

I thought I'd see what others thought about this theory.

Cheers,

Malcolm

[Malcolm Schweizer]

I guess I should clarify that I am suggesting that using hand tools could be BETTER for tonal quality than using power tools- in the ever-so-slightest way.

[Chris Fournier]

This is the kind of thinking, if done by 25 people or more that makes conferences that move the guitar as a stringed forward by zero. This is the kind of speculation that creates experts who have no way of proving their theories but are nonetheless wexperts. If you machine wood and generate enough heat to melt "sap" then you need to change your blades and move on. You are not dealing with the molecular minutiae, simply ignoring the fundamentals of woodworking.

Build as light an instrument as you can that will play for 30 to 40 years and you have built a guitar worth building. One that responds to the minimal string energy that it has and amplifies it as much and as honestly as it can.

Luthiers are pragmatic, hobby guitar makers are dramatic. Please feel free to tell me how you can hear two hand padded layers of shellac under lacquer comapred to vinyl sanding sealer under said same lacquer.

Build honestly and you will make a fine instrument, no amount of theortetical conjecture replaces solid execution. Remember that for the most part people want an instrument that sounds like something from 50 to 100 years ago, you ain't inventing, you're replicating.

I'm not brow beating the OP but certainly trying to be pragmatic. Stick to the well worn path and you'll be successful, cryogenically treat your spruce top and you're missing the point. Might as well sell your soul to the devil for divine tone a la Robert Johnson.

See you at the Cross Roads.

[Malcolm Schweizer]

Sounds like you already sold your soul to the devil. It was just a curiosity. Thank you for your colorful response.

[george wilson]

Nah,he's just passionate!!:)

[Chris Fournier]

I may have but it wasn't to build the perfect guitar!

If you use the classic materials and build well your guitar will sound great and as anticipated. I don't doubt that you've done so already!

[Malcolm Schweizer]

Actually I grew up in Mississippi and know where the crossroads are where old hwy 1 meets Hwy 61. I play a lot of slide blues. For that I prefer a crapped out cheapie rusted resonator.

Anyway, it was meant for coffee table type discussion, not world problem solving. The thought came to me as thinking about woods for the guitar and also thinking about sharpening on the grinder.

[Chris Fournier]

Actually I grew up in Mississippi and know where the crossroads are where old hwy 1 meets Hwy 61. I play a lot of slide blues. For that I prefer a crapped out cheapie rusted resonator.

Anyway, it was meant for coffee table type discussion, not world problem solving. The thought came to me as thinking about woods for the guitar and also thinking about sharpening on the grinder.

It would be interesting to know about the heat generated at the cutting edge when machining wood but boy would that be difficult to truly quantify. In metal working they say that a properly set up operation puts most of the heat into the chip. I wonder if WWK'g is the same?

A resonator's nasal tone always makes me pay attention, I really enjoy that sound.

[Mel Fulks]

I don't think heat is a big issue when machining wood unless the feed speed is too low. It is easy to over heat the steel while making the knives or sharpening them, even with the coolant flowing over them it's easy to burn the common cheap
grade of semi HHS while using the hard detail wheels to make the sharp corners etc. With the real HHS,usually only gotten by up charge and demanding it by grade, the same amount of heat doesn't spoil the knife.

[William Adams]

It's an interesting idea.

Might even be a way to work out testing it (cut two book-matched pieces of wood by hand, then plane each down to identical dimension, one by hand, the other w/ a machine), but the problem is even the double-blind tests which I'm aware of are inconclusive --- music is fundamentally an expression of emotion and spirit, which is a hard thing to unambiguously test for.

[george wilson]

Are you using air dried or KILN DRIED wood(already subjected to heat)?

This is one of those threads where we are debating how many angels can dance on a pin head. I mean,really,how hot do your tools get?:) I haven't noticed in 50+ years significant heat in wood coming out of a thickness planer. Maybe if you let the knives get as blunt as butter knives.

[Matthew N. Masail]

It has been said about Torres the during glue up he rubbed the back with alcohol (or something) a lit it on fire, it would burn for a few seconds, re-heating the hide glue so he could apply pressure and be sure of a solid glue joint. so.. heat bad? I dunnu, wood can also get pretty hot setting in the sun.

[george wilson]

Back in the old days,when luthiers had no air conditioning to control humidity,they'd heat the soundboard in front of a fireplace to shrink it before gluing it down,avoiding cracks later on.

If you noticed in my film about making the spinet,I heated the soundboard quite hot(without scorching) in front of the big fireplace. Then,it was glued down. I measured across the maximum width with a ruler before heating. After heating,the soundboard was at least 1/16" narrower than when cold. The soundboard was thus prevented from getting a severe crack in a future dry season. It has never cracked to this day.

Heating tropical woods before gluing is a good idea. Ebony especially is a "cold" wood. Warming it,or rosewood,CAN help the glue. But,it also shrinks the top or back before gluing. Don't get carried away trying this. Spruce can suddenly shrink drastically in one place,and ruin a top.

Torres was just using a variation of this process.

For your info.,fly rod makers TEMPER their Tonkin cane bamboo in an oven at 350º F for 15 minutes before making fly rods out of it.

[Chris Fournier]

Back in the old days,when luthiers had no air conditioning to control humidity,they'd heat the soundboard in front of a fireplace to shrink it before gluing it down,avoiding cracks later on.

If you noticed in my film about making the spinet,I heated the soundboard quite hot(without scorching) in front of the big fireplace. Then,it was glued down. I measured across the maximum width with a ruler before heating. After heating,the soundboard was at least 1/16" narrower than when cold. The soundboard was thus prevented from getting a severe crack in a future dry season. It has never cracked to this day.

Heating tropical woods before gluing is a good idea. Ebony especially is a "cold" wood. Warming it,or rosewood,CAN help the glue. But,it also shrinks the top or back before gluing. Don't get carried away trying this. Spruce can suddenly shrink drastically in one place,and ruin a top.

Torres was just using a variation of this process.

For your info.,fly rod makers TEMPER their Tonkin cane bamboo in an oven at 350º F for 15 minutes before making fly rods out of it.
\
Easy there George! Cane rod builders formulas for heat treating Tonkin are myriad, infact cane rod builders are about the only craftsmen who are as supersticious as instrument builders! Having built both I can say that careful construction and quality materials trumps voodoo every time. Tempering cane is very effective, "my" recipes would have to be beaten out of me. Or searched for on the web where all can see...

This is after all where I got them. Oh yeah and in books that I paid for.

[Shawn Pixley]

Relative to the other 54,000 things that go into an instrument, I think this is a relative non-issue. It is an interesting question though.

[William Adams]

Apparently bowyers used to be very superstitious as well, but a bunch of research was done and discussed and reproduced and published, culminating in the Traditional Bowyers Bible series (now up to 4 volumes).

But, how far/fast an arrow is propelled is much easier to measure and far less ambiguous and emotionally charged than the tone of a musical instrument or whether or no a fly rod helps one fish.

[george wilson]

I am not a fly rod builder,and my recipe was given to me by a guy who is,for whatever that's worth.

During the Vietnam war,builders apparently had to hoard their supplies of that bamboo.

[Malcolm Schweizer]

It was a curiosity- like the "is there life on Mars" debate, except without sending billions of dollars to find out there isn't.

Chris- I got to visit Torres' shop when I hiked the Camino de Santiago across Spain. It was an awesome thing to see the guitars in their collection.

[Julie Moriarty]

Are you using air dried or KILN DRIED wood(already subjected to heat)?

The latest FWW has an article about putting wood in the oven in your kitchen. :confused:

In another article they discuss moisture content and include images of the USA showing MC changes for indoor wood between the summer and winter. There's one section in western Kansas, that touches Oklahoma and Texas to the south and Nebraska to the north, where there is close to zero MC seasonal change for indoor wood. Seems like a good place to build instruments.

[Brian Blackburn]

I would guess you would have a better chance of getting some compression hardening on the surface with a machine than by hand plane. The machine hardening producing a brighter more live reflective toned instrument. Then top it with a more natural thin matte laquer finish (actually the same as gloss except the addition of a flattening agent).... Then charge more for the easier to build instrument.

[george wilson]

Just choose harder spruce. That's what I like.

[Chris Fournier]

Apparently bowyers used to be very superstitious as well, but a bunch of research was done and discussed and reproduced and published, culminating in the Traditional Bowyers Bible series (now up to 4 volumes).

But, how far/fast an arrow is propelled is much easier to measure and far less ambiguous and emotionally charged than the tone of a musical instrument or whether or no a fly rod helps one fish.


Superstition is a human condition and it has been the cataylst for a lot of nonesense, musical instrument building practices being one of the more benign instances, war and religion however...

[george wilson]

I stay away from guitar forums because they are so full of nonsense and know it all kit builders. You'd think being with a group of similarly interested guys would be nice,but no.

[Julie Moriarty]

I've been considering building an acoustic guitar. Most of what I'm learning now has come from articles in the two GAL magazines I have received. I've read a number of times the importance of tonal qualities in the wood one chooses when making an acoustic guitar. One luthier said the most important decision you make when building an acoustic guitar is in the wood you choose for the top of the guitar. That seems to be an across the board attitude toward acoustic instruments - that the wood must "sing".

What I have not yet seen is how these artists identify and mill the wood to achieve that goal. I know from working on the bass build that koa is a very difficult wood to plane yet it is one of the woods I see mentioned fairly often in GAL articles. I've sharpened my plane irons with a razor's edge to 8000 grit and I still have problems. When imagining milling wood for an acoustic guitar, I've seen myself resorting to a drum sander instead of planing when working with difficult woods. What I don't know is how sanding to final thickness might affect the sound.

[Chris Fournier]

Just choose harder spruce. That's what I like.

I would agree. Although red cedar classic is my favourite nylon string guitar top material.

[george wilson]

Cedar will never have the longevity of spruce. The cedar myth started when Ramirez,being cheap by nature,bought up a bunch of old,large cedar mine timbers,and had them quarter sawn into guitar top wood. I have made a few guitars with it. They are too dark sounding to suit me. Cedar does not have the inherent strength of spruce,or the ability spruce has to rapidly spread vibration.

Ramirez himself has been described to me by a friend who knew him as hardly being able to cross the street by himself. His father was the great builder. The modern shop employs several good luthiers who make the guitars. They are permitted to use a cheap looking rubber stamp with their initials on it to stamp on the neck block of guitars they make. My friend,back in the early 60's,was a commercial pilot. He'd fly to Spain,and while there,buy a Ramirez to re sell. They were cheap in Spain at that time. Ramirez would obligingly fill out a receipt that said the guitar was bought very cheap,to help get it through customs without big taxes.

[Chris Fournier]

Cedar will never have the longevity of spruce. The cedar myth started when Ramirez,being cheap by nature,bought up a bunch of old,large cedar mine timbers,and had them quarter sawn into guitar top wood. I have made a few guitars with it. They are too dark sounding to suit me. Cedar does not have the inherent strength of spruce,or the ability spruce has to rapidly spread vibration.

Ramirez himself has been described to me by a friend who knew him as hardly being able to cross the street by himself. His father was the great builder. The modern shop employs several good luthiers who make the guitars. They are permitted to use a cheap looking rubber stamp with their initials on it to stamp on the neck block of guitars they make. My friend,back in the early 60's,was a commercial pilot. He'd fly to Spain,and while there,buy a Ramirez to re sell. They were cheap in Spain at that time. Ramirez would obligingly fill out a receipt that said the guitar was bought very cheap,to help get it through customs without big taxes.

Cedar certainly doesn't have the playing life span of spruce but I find that it sounds far better right out of the gate. Pretty subjective stuff I'll admit but I'd take a cedar classic over a spruce any day, of course it's all in the ears and mine like cedar. Now plywood's got real tone that lasts forever...

[Matt Lau]

First off, I'm a hobbyist.
George is a great luthier, and his word should have more weight.

Personally, I really like cedar and the spruce I favor tends to be considered ugly.
I prefer properly air dried wood (I feel that it's more stable), but properly kiln dried wood works.
I prefer quartered wood over flat--for stability, not sound.
I prefer split braces--for strength, not sound.
However, I have some Adirondack spruce from 85 years ago that is stiff as all getout, brittle, and extremely light...almost like cedar on steroids.

Wood is an interesting material...don't you just love it?

-Matt

ps. George, I think my maestro agrees with you regarding Ramirez...something about being a talentless prick. On the other hand, he has respect for Fleta (ugly, but well put together) and Hauser (first class craftsmanship, but unforgiving). Did you ever know of Randall Angella?