Top thickness is, along with bracing, the most debated and tinkered-with area of guitar making.
Ervin Somogyi, Guitar maker, 2013
How thick to make a classical guitar's top is a subject of heated debate. I know, other makers, and amateur classical guitarists, have argued at me about top thickness. I see no point in arguing about top thicknesses, either you like my guitars or you don't. You are suppose to buy the guitar you love.
...Mr. Tatay motioned the young Newberry over to his workbench and, using hand gestures and some coins, indicated to him that the secret to his lutherie was to make the guitar top about the thickness of a nickel in the middle, and the thickness of a dime at the edges.
These two coins have been in my jean's pocket for the last two weeks, so I can pull them out throughout the day and feel how thick they are between my thumb and forefinger.
According to my General brand caliper, a nickel is .070 inches thick, or about 1.8mm...
a dime is is .046 inches thick, 3/64th of an inch, which would make it between 1.1-1.2mm thick.
This is a Port Orford cedar guitar top that is going to be paired with some "wild grown" East Indian rosewood. The caliper is on the very outside edge of the top, it measures in between 1/32th of an inch and 5/64ths of an inch, a hair or so over .070 inches, or about 1.8mm. So I got the top's edge to a little more than a thickness of a dime.
Just so you know, I made this top last fall, before I read through Mr Somogyi's article. I was using the top thicknesses of Spanish guitars that were made in the 1960's as a guideline.
Here at the middle of the top at the sound hole, the thickness is almost 3/32nds of an inch, about .090 of an inch, or somewhere around 2.2-2.3mm.
Should I go thinner? Maybe. I won't know until I glue the fan braces on and "tap tune" the top. Remember, Mr. Tatay said about the thickness of a nickel and dime.
When the great guitar maker, Antonio de Torres, was asked what his secret was for making such wonderful sounding guitars, he answered by holding up both his hands and put his thumbs to his fore and middle fingers. He said that knowing how to thickness a guitar's top was the secret, which was no secret to other guitar makers.
The United States is the world's largest producer and consumer of wood products harvesting about 350 million tons of round wood annually.
Forest Products Laboratory, USDA Forest Service
When I dismantled the old workshop I made sure that I inspected every stick of wood that came out of the building to see if it could be used in making a guitar.
There wasn't much, most of the Douglas fir 2x4's were too knotty or had amazing amounts of runout to be used, all of that went into constructing the new tool shed. I did find a couple of 2x4's that were white fir, abies concolor, that showed some promise.
I cut out the parts that looked good and split them, the failure rate was pretty high, lots of run out. One piece that is suitable has the old sawmill stamp on it, I believe it is a West Coast Lumber Inspection Bureau stamp. I went to their website, click here, and found that Mill 74 is no longer in operation. This piece of wood is definitely white fir! The old workshop was constructed about 1964, which means this stick of wood is two years younger than me!
This is from a new 2x4 that I used to frame my new workshop. As you can see it is stamped Doug Fir-Larch and was milled at Priest River, Idaho. Go to the Western Wood Products Association webpage to see a listing of all the mill currently in operation. I am not sure if this piece is Douglas fir, it's a little too light in weight and really doesn't have the pitchy Douglas fir smell to it, it could be Western Larch.
Check out the medullary rays in this piece of white fir! The Douglas fir/larch piece also has some glorious medullary rays.
Here is a guitar top made from redwood that I purchased from Redwood Bears and Burls in Gasquet (Gas-key), California. You can also find their products on eBay, just look for "renobird". The "fan" braces are from the old piece of white fir and these braces are surprisingly stiff and light. When I was single and living in Northeastern California, I cut and splits cords of white fir for firewood, even then I thought that it would make good brace wood for guitars.
Today was also baking day! I started baking bread again, I forgot how much I enjoy it!
I am slowly dragging myself into the 21st century, I just reactivated my Instagram account.
Look for highcountrylutherie on Instagram for daily updates on what I am working on in my shop, mostly guitars, though I may post about something else.
I would put a "link to button" for Instagram on this blog, but the directions I found this morning on Blogger Help didn't work, and the websites that were suggested for add-ons, well, their platforms were for everything else but Blogger. Sigh. I need to hire a web designer.
I have a Facebook page, too, Wilson Burnham Guitars, but that really isn't much different than Instagram or this blog.
A snowflake is one of God's most fragile creations, but look what they can do when they stick together!
Author Unknown
Cold weather and snow delayed me in getting down the corrugate tin roofing on the new workshop. January 3rd proved to be a day of snow flurries and sunshine which at least allowed me to install the roofing. Then it snowed six inches.
The temperature fell to -5 degrees Fahrenheit and it kept snowing...
...until there was 22 inches of snow on the ground. And the temperature fell some more to register -14 degrees Fahrenheit on the thermometer.
Yesterday, the temps warmed up to 36 degrees Fahrenheit with the wind gusting up to 50 mph and we lost power for about two hours.
This morning we woke up to rain and warmer weather. I am very glad that I got the new workshop "dried in" before all this snow fell.
The high reached 40 degrees today with rain and snow flurries, there is a good six inches of slush underneath all the snow. No wind to speak of today, though some locales all the foothills had wind gusts up to 90mph, it was a very quiet day here.
The forecast doesn't call for sunny skies until Saturday, on that day we will drive nearly two hours out to Wiggins. Colorado to a butcher shop to pick up a quarter of beef that we bought from friends of ours who run Angus cattle near Sterling.
Maybe next week I can start putting up the siding on the new workshop.
Although this may seem a paradox, all exact science is dominated by the idea of approximation. When a man tells you that he knows the exact truth about anything, you are safe in infering that he is an inexact man. Every careful measurement in science is always given with the probable error ... every observer admits that he is likely wrong, and knows about how much wrong he is likely to be.
Bertrand Russell, in The Scientific Outlook, 1931
When I first started making guitars, Guitarmaking: Tradition and Technology, by Cumpiano and Natelson, was my best guide. One problem I ran into with this book is that the authors recommend using a machinist's ruler graduated in tenths of an inch to use in making a guitar. At the time, I had a hard time finding an affordable machinist's ruler that was longer than 24 inches, I ended up buying a double sided ruler, both imperial and metric, from Bridge City Tools. As I did more research into classical guitar construction I discovered most of the books available worked with the metric system and used it to take measurements of historic guitars. I never really gave much thought to either system, both accomplish the same task, namely measurement.
Recently, I re-read an article on the restoration of an 1863 Antonio de Torres guitar by the luthier R.E. Brune. (Click here to read the article). In the article, after describing the guitar, Mr. Brune states "Aside from the lack of fan struts, there are several other notable features. The first is its adherence to English measurements based on the inch."
Wow, a Spanish carpenter using the English Imperial system of measurement! Torres worked as a guitar maker from about 1845 to his death in 1892.
Of course, Mr. Brune doesn't address why Antonio de Torres used the English system.
My first question was, why didn't Torres use the Spanish unit of measurement, that of the vara, pulgado and pie? These units of measurement are descendants of the Roman foot, very ancient, well used and loved by the Spanish. Yes, I know that the length of the vara was different in each Spanish town and province, but why would a man who apprenticed as a carpenter in his hometown take up a unit of measurement used by the English?
The second question I asked was, maybe Torres did use the vara to layout his guitar plans and nobody used a vara to measure his guitars.
I made a ruler based upon the Spanish vara to test this theory very unscientifically.
As I understand it, the vara was/is equivalent to our "yard". Juan Villasana Haggard, who wrote Handbook For Translators of Spanish Historical Documents, states that the official historical vara was 32.91 inches; a codo equals one half a vara, 16.5 inches; a pulgada, consisting of 12 lineas, equals 0.914 inches; a linea equals 1/432 of a vara, or 0.0769 inches; a dedo equals 1/48 of a vara, 0.6949 inches; there is more, but I think you get the idea. Another source states "(t)he standard vara was the vara of Castile, (about 0.8359 meter, subdivided into 3 pies or 4 palmos)". A palmos is 8.23 inches, a pie is 10.97 inches.
I ripped and planed down a piece of maple, I sharpened the points on my old Lodi brand dividers, set to them to that space between 29/32 and 59/64 and went on a wild ride for 26 pulgadas.
When I placed the new ruler next to my trusty old Bridge City ruler, imperial side, I saw no marks really lined up, no pattern emerged.
One half of the 25.625 inch scale length is 12.812 inches, and as you can see, the new ruler really doesn't line up with 12 and 13/16 inches.
I flipped the Bridge City ruler over to the metric side and again, no alignment or pattern either. Half of 65cm is 32.5cm.
Yes, I probably should have spent more time dividing the pulgadas into 6ths, 7ths, 8ths, 10ths, 12ths, 16ths, etc., but I need to buy better dividers and I am not sure I need to explore this side street further at this time.
Third question: was there a connection between the violin and guitar makers of Seville, Spain and those of England?
Last night, while surfing the Internet for "English unit of measurement and Spanish guitars", I stumbled onto a thread that was up on a well known classical guitar forum. I won't mention the forum's name, I find forums a waste of time, mostly because of the dilettantism you find in forums, but, I will say I think I actually found the start of answer to my first and third questions.
A well known guitar maker mentioned that he had done some research on Spanish carpenters and guitar makers and learned that most of these men tried to purchase English made tools and rulers. Why English tools? They were the best tools available. The only problem with this maker's thread post is he does not cite his reference for this claim.
This maker also states that he has examined guitars made by the great Jose Ramirez III in the 1960's that layout perfectly to the English inch. That statement correlates with a statement made by the late Eugene Clark, a wonderful guitar maker, who said that nearly all of the guitars made by the great Spanish makers that he had repaired, laid out to the English inch.
What a thought, Spanish guitar makers used the English inch into the 1970's! And Spain officially adopted the metric system over one hundred years earlier!
Here are some photos of a plan of a 1963 Hernandez y Aguado classical guitar from Roy Courtnall's collection purchased from LMI. All measurements on the plan are metric, but notice that the drawing lines up well with the English inch.
Overall length of box, 19 1/4 inches.
With of lower bout, 14 3/4 inches.
Where to from here?
I will look at the bibliography in Tools: Working Wood in 18th Century America, by Gaynor and Hagedorn, and The Tool Chest of Benjamin Seaton, by TATHS for paths to research British tool and ruler exports to Spain. At some point, I hope I can find books on the history of woodworking and carpentry in Spain. I also need to email that guitar maker about his references for Spanish carpenters and their English tools. If anyone has any suggestions for research possibilities, please let me know!
