You can view our archived newsletters
Oct. 20-25, 2013
Upcoming Luthierie Camps...
Jul 27-Aug. 1, 2014
Nov. 16-17, 2013
Open Shop Intensive:
April 3-6 2014,
Tools & Fixtures
Please visit our website or email Kali for more information about these programs.
As I prepare this newsletter, Rosemary and I are on the road, and are soon to be heading towards Plymouth, California to attend the Bluegrassin' in the Foothills
festival where we will be giving two workshops, as well as doing as much jamming as we can. I hope we get to meet some of you there, or at other festivals wherever they (and you) may be.
As we head west toward the Sierra, I have been especially pained by the Rim Fire that was raging through the California mountain ranges just South of Yosemite (and about 125 miles from our shop). In the first week of September, the Rim Fire - now the fourth largest fire in California history - has consumed more than 250,000 acres (that's almost 370 square miles). Homes. Wildlife. Trees. Gone. Two weeks prior it was thought that the fire might consume the amazing giant Sequoias on Yosemite's southern rim, and the very thought of it triggered my memory of walking beneath this amazing stand of magnificence just a few years back; the idea of their possible destruction made me gasp.
You may have guessed that I have a special reverence for wood. There isn't a piece of it I cut that doesn't make me think first about this gift Mother Nature's has given us. And we're not cavalier in the shop about laying out our boards and thinking how to get the very best yield and usage of every piece. Our primary focus in planning our yield is not a financial one (although it should be) but more a sense of ownership and value of the wood we have, and how to treat it, and how to most effectively convert it to usable necks, soundboards, and backboards with care and integrity. To us, it's not just "wood."
Our wood - especially the woods we use for luthierie - is such a special and valuable natural resource. It's one thing to have the doors of availability get closed by the Lacey and CITES embargoes, but it's another to have our precious wood turn into smoke. I hope you think dearly about the wood in your shop, and protect it, care for it, and use it wisely. What takes centuries to grow can be gone in a spark of history.
On a much lighter note, I'm really excited to announce that Kali and Amy have worked hard to expand the capabilities of our on-line store
to include 24/7 on-line order processing for several foreign countries who previously had to order from us over the phone. These now include Australia, Canada, Finland, France, Germany, Ireland, Italy, Netherlands, New Zealand, Norway, Spain, Sweden, and the United Kingdom. If your country is not included, please send Kali an email
, and we'll try to include it in our next round of updates.
We've scheduled April 3-6, 2014
as a weekend for an Open Shop Intensive program for our Luthierie Camp alumni to come and do whatever work they need to do to finish up their instruments. Our shop, tools, and finishing equipment will at their beck and call, as will Ken, Nolan, Kali, Amy, and I to help in whatever way we can to bring the Camper's instruments to completion, and do some final setups and adjustments. If you're a Luthierie Camp Alumni and are interested, please contact Kali
While on the subject of Luthierie Camp
, as of the writing of this newsletter, we have one bench available for our October 20-25, 2013 program. If you'd like to join us, again, please contact Kali
And finally, we've been busy beavers working diligently to bring you another great product. This month, we are happy to announce the Siminoff GoBar decks for mandolin and mandola. These amazingly well constructed and durable decks are constructed with the very best care and materials. You can read more about them further in this newsletter
Hard to believe it's September - thanks for your continued business, and...
Thanks for building with us...
A Short Treatise on Truss Rods
A truss rod is a vital element of the neck that is used to help keep the neck straight under the continuous load of the strings' tension. The compressive force of the strings - which on a mandolin loaded with J74 strings is about 160 pounds - wants to pull the neck into a curve that results in a "hollow" in the center of the fretboard. And, just to get our terminology correct, a "hollow" is a low spot in the center of the fretboard, and a "bow" is where there is a high spot in the center of the fretboard.
Prior to 1922, most acoustic string instruments featured some form of laminated necks to prevent the neck from developing a hollow. Prior to Gibson's truss development in 1921, the Company mortised a piece of maple into the mahogany necks. And to keep up with the competition's marketing of laminated necks, they placed a thin strip of died pearwood down the center of the back of the neck to give the appearance of two-piece laminated necks (which they were not). In 1921, just prior to the announcement of the F5 mandolin, Gibson's engineer Thaddeus "Ted" McHugh applied for a U.S. Patent for a steel rod embedded in the neck to correct for the neck bending under the load of the strings, and keep the neck straight for the life of the instrument.
As you can see in McHugh's patent drawing, the rod was embedded in the neck with the center portion of the rod close to the fretboard, and both ends of the truss rod set low in the neck. McHugh's vision was to pull the bottom of the peghead toward the neck heel, and in so doing cause the neck to bend upwards creating a high spot in the neck when the nut was tightened. Unfortunately, his design was flawed and the truss rod was wrongly positioned upside down. As a result, when the nut was tightened and the a load put on the rod, the rod wanted to straighten which resulted in a low spot in the center of the neck - exactly the opposite of what was desired. This upside down truss rod was used on all instruments - including F5s and H5s - from around 1921 to 1932, when someone in Gibson engineering recommended that the curvature of the rod be inverted so that it would be positioned low in the center of the neck and high at both ends of the neck. Then, when the rod was tightened it would pull the neck into the desired bow as the rod straightened.
Straight rods work well, too - a lesson I learned from friend and Luthier Tom Morgan of Dayton, TN. The straight rod puts the low portion of the neck in compression while the ebony fretboard attached to the surface of the neck cannot be easily compressed, and this results in the neck bowing nicely. For almost 20 years, I used the curved rod (with a low center) until Tom proved to me how well the straight rod worked back in 1978 or so.
An alternative to using adjustable truss rods is to imbed carbon fiber bar stock in the center of the neck, but this is a choice that I do not recommend. While carbon fiber is very strong, it does bend. Secondly, the carbon fiber rods are not adjustable - you set them and forget them (until you need to square the neck!). Then, even if the carbon fiber could not bend, both the adhesive around it and the neighboring wood could take a set that would allow the neck to bend. And, lastly, carbon fiber is very light; much lighter than a steel rod, and much lighter that the wood around it. Mass and density in a neck is very important in aiding both amplitude and sustain, and carbon fiber does not support either of these two needs.
There are two-way-acting truss rods, also known as double-acting truss rods. These are intended to correct for either a bow or a hollow by having the ability to bend either upward or downward depending on the direction you turn the adjusting nut. However, it is VERY rare that a banjo or mandolin neck develops a "bow" (a high spot in the center of the neck) when under a continuous string load - which is what double-acting truss rods are designed to correct. Since "bows" are VERY rare, having a truss rod to correct one is, in my opinion, overkill.
A standard single truss rod
- properly installed - will do an excellent job to keep an instrument's neck straight, and it is my opinion that the neck of every string instrument (other than violins and ukuleles) should have one.
Attach your soundboards and backboards with a Siminoff GoBar deck, just like the one we use in our Luthierie Camp and in the shop. Our 3/4" fixture-grade Birch plywood decks ensures a rigid and sturdy support for both mandolin and mandola construction. Complete with 24 rubber-tipped, coated fiberglass rods, support rods, nuts. Order Part #355
($179.00 plus P&H).
Our Siminoff spool clamp set features hard rubber pads that provide continuous pressure as glue squeezes out, cures, and shrinks. Rubber pads don't slip and won't mark or marr the soundboard or backboard. The 4" threaded shafts and wing nuts fit mandolin and mandola bodies. 24 pcs per set.
Order Part #3000
($39.95 plus P&H) in the online store.
This is rare find: A lab notebook from Professor Lloyd Loar's last class on musical acoustics at Northwestern University, Evanston, Illinois in the summer of 1943. It was prepared by one of his students and has been transcribed by Roger H. Siminoff along with his supplemental notes. A quick read, or dense read, depending on your preference. Visit it many times for a new takeaway. The notebook includes 11 lectures on musical acoustics, vibrations of strings, ideals of tuned air chambers, and much more. The original illustrations were scanned for this book to keep the information as close as possible to what Loar may have drawn on the board. Spiral bound, 44 pages. Order Part #508 ($24.95 plus P&H) in our online store.
Luthier's Tip: Inlaying Rosettes
We're glad to see so many folks building F4 mandolins
and H4 mandolas. These instruments feature a rosette
around the soundhole that in addition to decorating the soundhole, provides a small amount of strength to the cross-grain area of the soundboard around the soundhole.
The question that always pops up is "what's the best way to cut the rosette channel?" The channel is fairly easy to prepare and actually takes more patience than skill:
Begin by positioning the rosette in the exact location you wish it to be, ensuring that it is centered on the soundhole. Next, secure it in place with two small "C" clamps; use small leather cauls between the clamps and the rosette to prevent damage to the rosette.
The next step is to very carefully go around the inside and outside edges of the rosette with an X-ActoŽ knife fitted with a sharp #11 blade. This first pass of the blade is to create a perfect outline of the rosette on the instrument's soundboard. Be sure to hold the knife perfectly vertical so that the cutline is neither wider nor narrower than the rosette. As you near the clamps, add a clamp where you already cut the outline, and then remove the clamp that is in your way.
Once the outline is cut all the way around the rosette, remove the clamps and the rosette, and very carefully cut the channel deeper, going about 1/16" into the soundboard. Be careful to stay within the outline-channel; the knife will have a tendency to follow the wood's grain, not the outline's channel, so you have to go slowly and hold the knife steady.
With the outline cut, the next job is to remove the wood in the center with a small sharp chisel. Work to remove all the wood and to level the bottom of the channel.
It's really a fairly simple task and if you do it carefully, the result will be a perfectly fitted rosette. If you would like more details on the process and to learn how to glue in the rosette, you can download a free instruction sheet on how to install a rosette
(PDF document) from our website.
|Q & A: Readers Ask|
: I know this is not really a building question, but is there some easy or special way to put strings on an instrument so that you can take them off easily? I find I have to loop them through several times and they still slip. I've just not found it fun to change strings.A
: Well, I don't know if I can make it fun for you or not, but yes, there's an easy way to attach strings so that they hold securely, and can be removed easily. And thanks for the question - this is a perfectly good place to ask and answer questions related to string musical instruments.
There's a simple trick that will help you to put strings on easily and have them lock in place and not slip. The key is to get the string to wrap around itself so that the tail of the string locks under the first wrap. Here's how you do it:
With one hand, insert the string straight into the post's hole while the other hand holds the string about 1˝ above the fretboard as shown in Fig. 1. (This excess string is what will later wind up on to the string post.) If the string is going into posts on the bass side, bring the tail of the string back around the post clockwise as shown in Fig. 2. If the string is going into posts on the treble side, bring the tail of the string back around the post counterclockwise.
Now bring the tail of the string under the main portion of the string that is going into the post (Fig. 2), raise it up, and pull it forward. This causes the tail of the string to be locked in a "C" shape behind main portion of the string (Fig. 3).
As soon as you begin to tighten the string up on to the string post, the tail of the string - where the "C" bend is - gets locked against the post.
When in a hurry, I have actually installed a string using this method without leaving excess string to wind up. The locking turn holds securely and quickly, and it can be released just as quickly.Have a question? Be sure to send it in and we'll answer it in an upcoming issue. Remember, we won't post your name, and chances are, if you have a question, someone else probably needs the same answer!