Stay in Tune vol# 121
By Luthier Patrick Podpadec
It feels a bit strange that my son is back in school already and it still feels like it's full on summer. There are still music festivals going on and every weekend it seems that there is all kinds of things going on. Mother Nature has blessed us with some pretty good summer weather this year after having blasted the crap out of us last winter. I hope it never ends.
The one thing about nice weather is that it makes it hard for me to be inside working in my shop when the sun is shining. I want to be outside doing something. Even mowing the lawn is okay. Sometimes I just have to "bite the bullet" and work inside anyway.
In the last article I tried to explain how long it would or should take to build a guitar. I know I kind of rushed through the process and didn't give a lot of detail to some of the procedures. Because there are so many processes that are involved I couldn't spend too much time on anyone in particular or I wouldn't of been able to fit the article on one page. This week I will slow it down some and take one thing at a time
This past week I have been working on getting the brace material cut up and glued to the top and back of the harp guitar that I'm building. You might not be aware of this but most guitar tops and backs have a bit of an "arc" built in to them . It's easy to see this most of the time on the backs, but the tops also have about a 30ft. radius built into them too. That doesn't sound like much but each brace must be shaped to this radius before glueing to the top. We are really only talking about the main "X" braces. All of the other braces are too short in length to put a radius on them. I have found that the best way to glue the braces is by using a "Go Deck".
This is a open box that uses the top or lid of the box as a fulcrum point by using 1/4" rods to glue down the brace. The bottom of the box has a 30 ft radius dish that you lay the top on and then flex the rods to glue down the braces. It sounds strange , but it is very accurate and it eliminates the problem of "creeping". This is where the brace wants to slide out of position when you exert pressure from a normal clamp. You can also glue more braces up at one time because there is no clamps to get in the way. Some luthiers prefer to glue the braces on the top and then shave or shape them while being glued .This gives them the ability to "tune the top to a frequency that they feel will produce the best sounding guitar. Although I understand and believe this method has its merits, it is not how I prefer to do it. I believe it is very hard to judge how the top will sound at this early of the building stage. I tend to "feel" the stiffness and weight of the top to determine the final sound. After you glue the sides, back and neck to the instrument, whatever your top was originally "tuned" to will change dramatically from the added weight and structure. Although it is true that the top is responsible for 90% of the tone, the final sound is a culmination of all the parts vibrating in harmony with each other. This to me is the art of lutherie. Being able to adjust the tone by using the right combinations of woods along with being able to "feel" the density of each piece that you assemble . Making sure that each thing you do reacts with the next thing you do, so on and so on. It may be hard to express this in words but the first time you complete your first instrument you will begin to understand the relationship that all of the parts have to one another. I feel that the best instruments have the tone vibrating through the whole instrument, not just the top. I also feel the "lighter you can build the instrument the more tone will be able to vibrate through it. When a guitar is "heavy" or overly built the mass just seems to suck up the vibrating tones. A good example of this is some of the older Martin guitars that have small very lightly braced tops that just sing like angels. There is a fine line that must be acknowledged because the lighter you build the more susceptible you are to structural damage. You must consider the fact that you have a thin piece of spruce counteracting with about 200lbs. string pressure that just wants to rip it in half. Many first time builders (including myself) tend to "overbuild" to compensate for string pressure. The theory of "Better to be Safe than Sorry" is not always the best way to go when building an instrument. There is a lot going on inside a guitar while it's producing it's sound and having the ability to adjust to it or being aware of that is what makes some builders better than others. To me it is an "eternal dance" with physics that drives me to be a better luthier . Trying to figure out how or what makes a certain piece of wood , or even a composite material to vibrate at a specific tone when it is strucked or plucked or hit or banged. I believe the trick is to use the right combination of woods, structure and design so that the tones are evenly spread out over the range of sound that the "box" (guitar body) is capable of. (I hope I'm making at least a little bit of sense, sometimes I wonder)
It's the search for the "holy grail" for me. and I will continue to search for it until I find it. I hope the same for you! So until next time, I bid you all a farewell and please stay in your lane and of course "Stay in Tune"
Patrick from Liam Guitars/Wood-n-Strings