Why book match ?

Brian1

Brian1

Well-known member
Joined
Nov 15, 2014
Messages
557
Reaction score
0
Location
Texas
I am not a builder, probably never will be, I can barely use a screwdriver, (not that one would be needed to build a ukulele) but I really find it interesting to learn how things are made and why things are made the way that they are.

One of the things that puzzles me is why when building a guitar or ukulele a piece of wood is selected and cut half the size of what is needed and then the two pieces of wood are glued together to make the top or back of an instrument.

Wouldn't it be more simple to start with a single piece of wood twice the size ?

I understand that in some cases an esthetic reason might be to have a mirror image for symmetry, particularly if the wood has a unique patten in the grain, but when I watch instruments being built out of a very straight grain wood I see videos of builders book-matching the pieces together as well.

I could also understand particularly on a guitar if the pieces of some woods may not be large enough for the entire face or back, that would make sense too because some woods probably don't come in a 4'x8' sheet from the Home Depot. But for a soprano ukulele ? If they are cutting down the tree you'd think you'd have enough for a ukulele. :confused:

I noticed this kit, seems it may (or may not) have two pieces glued together to form the back and top of the ukulele but it looks like it is one single sheet (or is it ?) http://www.stewmac.com/Materials_and_Supplies/Kits/Ukulele/Tenor_Ukulele_Kit.html

and is that a good thing or bad thing if it is one piece verses two ?

This is probably a longer than needed opening post, and the answer will probably be very obvious, and can probably be answered in one sentence so I am prepared to look foolish.
 
Last edited:
The width of the boards used are smaller, and more product can be made with less waste.
 
consitter said:
The width of the boards used are smaller, and more product can be made with less waste.
Click to expand...

Thanks for the reply, but I am particularly dense and may eventually need a diagram, by width do you mean thickness ? Because I don't see how it creates less waste, when the surface area is doubled I would think the waste is the same amount.

But is it simply that when I pay $1000+ for an instrument the cost of labor verses the cost of wood is better if they cut two pieces and put them together ?

Does it help/hurt the sound quality or anything else ?
 
Brian1 said:
Thanks for the reply, but I am particularly dense and may eventually need a diagram, by width do you mean thickness ? Because I don't see how it creates less waste, when the surface area is doubled I would think the waste is the same amount.

But is it simply that when I pay $1000+ for an instrument the cost of labor verses the cost of wood is better if they cut two pieces and put them together ?

Does it help/hurt the sound quality or anything else ?
Click to expand...

So I don't make a complete ass out of myself, I'm gonna let an expert weigh into it, instead of trying to remember what a luthier told me several years back. It made really good sense at the time, but at the moment, it's all garbled up in my head and will probably come out wrong.
 
consitter said:
So I don't make a complete ass out of myself, I'm gonna let an expert weigh into it, instead of trying to remember what a luthier told me several years back. It made really good sense at the time, but at the moment, it's all garbled up in my head and will probably come out wrong.
Click to expand...

That makes me feel better for not understanding completely :)
 
consitter said:
And yet another...the first reply is from the luthier that built my custom, and he told me pretty much exactly what is said here, word for word. Until now, I didn't even know that he had ever posted on UU.

http://forum.ukuleleunderground.com/showthread.php?8369-Two-piece-or-one-piece-top-and-bottom
Click to expand...

Thanks and thanks again. Also I am sorry I didn't do a search before asking. (I used to be a moderator on a different type of forum and it was one of my pet peeves)

I read both threads but I am still not sure about the answer other than there are a few reasons different people do it.

a. Some wood like Koa isn't very wide and I understand that, its what I meant when I said you couldn't get a 4x8 sheet.

b. It is hard to cut something less than 6 inches in smaller shops. I am not sure I understand this issue but I am guessing that if for math's sake 6" made 12 half tops of a ukulele (one uke per inch) there would be a smaller 6'' block at the end where if the block was larger instead of loosing 6 ukes worth of wood you would be loosing 12 ukes worth of wood. One would think that another saw could be used or possibly if gluing things together works for building tops you could glue two 6'' pieces together but Im no expert.

c. Some people think it makes a better sound, others don't, it seems agreed that on a small instrument like a ukulele it makes little if any difference.

But both A & B are the POV of the luthier, I guess I am thinking from the POV of the customer, who only wants to buy the Koa (or whatever) that is used to make my instrument. (that wasn't what I originally had in mind when I started the thread but it is what is registering with me now. )

Spruce for example is not as scarce or pricey but is also book matched. And I am still confused.
 
Last edited:
The wider you cut, the bigger and more accurate your machines have to be, to get an even cut me thinks. 2nd ly the trees have to be quite large.... to get a decent size piece of quarter sawn wood out. Please note that I am not a luthier.
 
The starting point is that you want wood which has vertical grain - seen on edge, like this: |||||||||||||||||||||||||||||||||||||||

If you think about how a tree grows, you can't cut much wood like that from one. In essence, it's one thick slice from the edge to the middle, and another one opposite it (you might get perhaps 4 tops from that slice). So choice is heavily restricted just by this.

Second, it has to be wide enough for your top or back. Both customer and luthier want the grain to be of reasonably consistent width, and trees produce wide grain in the middle (when they are young and growing fast) and bark on the outside. So you need a tree which is twice the diameter of your top plus a margin to cut off the bits you don't want.

Then you discard all the wood which has knots, or uneven or wavy grain that won't work structurally or visually, and so on.

All this means that one piece tops are really hard to find for guitars, and not that easy even for soprano ukes.

If you can use parts of your discarded slices which are half the width of the top, you can make a two-piece top out of them. So you're using more of the wood, which means a cost saving. Plus these narrower boards are cheaper than the equivalent full-width boards, because they're less rare, so again there's a potential cost saving.

If you decide to make a two-piece top you want the two halves to match; if you take consecutive slices from the same board these will be very close in colur and grain pattern. That's your bookmatch if you glue them up right, and it also gives a pleasing symmetry.

The cutting bit is simple too. The wider the board you want to cut, the bigger the saw you need. Big saws are expensive. Big blades need to be thicker, so you waste more of what is already scarce and expensive wood. So that adds to cost.

From the customer's point of view, bookmatched wood is probably cheaper (leaving aside the premium for particularly pretty wood).

From the luthier's point of view, boards to cut for bookmatching are easier to find, and thus cheaper, and easier and cheaper to cut.
 
If you look at the first line of ProfChris's response you'll see the representation of vertical grain. All soundboard wood will have one edge more closely oriented to vertical than the other edge, and the grain will change from vertical to somewhat of an angled orientation as you move to the other edge. In other words it changes from |||||||||||| to ////////////////. (As viewed from the end of the top flitch.)

Most luthiers prefer to place vertical grain wood directly under the bridge area of the instrument because it's the stiffest portion of the top, resisting deflection from string forces while most efficiently converting string energy to acoustic energy. That's the whole point of a soundboard. If you use a wider one piece top then the vertical grain will be located along one side of the instrument, exactly what you don't want.

Re-sawing and book matching the vertical grain edges give the luthier the maximum width of this strongest portion of the board. That's the bottom line of bookmatching top wood. Cosmetics are secondary (in general), but you'll find exceptions to any methodology so it's not a hard and fast rule.
 
Its not hard to find a rule of lutherie that can't be successfully broken. Most builders want consistency across their top woods because its easier to know what to expect from it. A top that is split and book matched will almost always be more consistent than a wider one-piece top. Yet guys like Harry Fleishman sometimes use a top that is half spruce and half red cedar, and I recently read of a man who uses two kinds of spruce on the same top. The object being (I guess) to achieve variations of stiffness across the top. Some research will turn up four-piece tops as well as tops with the grain lines oriented at an angle to the centerline of the instrument. Tops with the end grain a degree or two off vertical can make killer guitars but must usually be left a bit thicker. Martin made an MTV model that mixed up rosewood and mahogany on the same body, which I suspect sounded just like their other models. Convention is the main reason instruments are made the way they are, though this seems to have broken down a bit in the last few years.
 
Thanks to those who responded.

I had not thought of the idea that grain that goes in a "V" shape would be stronger toward the bridge where the tension from the strings would be. That seems to make sense because the "V" shaped grain, the area under the bridge is usually enforced but being such an important point every assurance helps.

Addressing the issue of a larger blade being thicker and creating more waste, I'd guess if the blade would be more than twice as thick as the one used to cut smaller pieces to be put together from a conservation standpoint. And if it was only 3/4 as thick but too expensive to justify having it cut and built in the same location one would have to justify the cost of board cutting done by some outside source against having a saw and providing the labor of putting the pieces together. Provided the piece can't be cut thinner.

At the time I originally posted, I hadn't even considered the idea that it may take three pieces in some cases, and was also operating under the ( sometimes incorrect) assumption that full sized guitars were using two bigger halves. As well as the (sometimes incorrect) assumption that the one piece was never or almost never used to make a single top.

My original concern was simply why some put in the extra step. I guess the answer I find is the economy of time outweighed by the conservation of materials + resources/equipment.

(plus the idea that even if the top is re-enforoced under the bridge, it can be stronger if the grain is "V" shaped ?)
 
Related question...
...Any maker(s) known for using 1-piece tops?
I kind of remember older Martin sopranos having them. Are they more/less desirable?
 
Mahogany grows big, and Martin has whatever equipment they want. One-piece plates mean one less step in production. Even the Stew-Mac tenor kit comes with one-piece plates. Its not a big problem for ukes. Guitars are a whole other matter.
 
The Koaloha concert I recently acquired for a song is a one piece top and back. Date stamp on the neck reads 2002, the newer ones appear to be book matched. Both my old Harmony's from the 20's-30's and the one from the 50's-60's appear to be one piece mahogany tops and backs as well. Interesting thread I always thought it was only for looks.

~AL~
 
jcalkin said:
Mahogany grows big, and Martin has whatever equipment they want. One-piece plates mean one less step in production. Even the Stew-Mac tenor kit comes with one-piece plates. Its not a big problem for ukes. Guitars are a whole other matter.
Click to expand...

Actually, the Stew-Mac tenor kit comes with book matched top and back. Nice mahogany with good figure too...

I would like to re-post my picture of a one piece Sitka spruce top. It was taken with super bright light shining through which shows the different densities. Under plain light, the top has perfectly straight and even grain and you wouldn't know what lurks underneath.

Candeled Top.jpg

This subject has been discussed before, but I would like to add my humble, humble thoughts:

1) Book matching is more pleasing to the eye. We like symmetry. It looks harmonious and this is important in a musical instrument.

2) It is easier to control grain and run-out when using smaller billets of wood and more cost effective.

3) Structurally, the stresses in book matched are evenly distributed on each side of the bridge. In my one piece top, densities could be radically different from side to side and this could lead to stresses and failures on the less dense side. Possible racking. Not good. However, since the uke is under much less tension than say a steel string guitar, these forces are negligible and there should be no problem (probably).

4) Tone is more predictable because densities are more consistent across the soundboard which means that the instrument has a more consistent, reproducible sound and tone which is important to commercial manufacturers.

I just heard a beautiful one piece mahogany top the other day that was stunning. Very complex. I use one piece sitka 'cause they are cheap and some real incredible stuff is available. They come (I suspect) from "orphaned master guitar plates" which are too nice to throw on the scrap pile. It's mate, for whatever reason is flawed.
 
Littleriveruke said:
3) Structurally, the stresses in book matched are evenly distributed on each side of the bridge. In my one piece top, densities could be radically different from side to side and this could lead to stresses and failures on the less dense side. Possible racking. Not good. However, since the uke is under much less tension than say a steel string guitar, these forces are negligible and there should be no problem (probably).
.
Click to expand...

Makes sense. .. didn't think of that.
 
Littleriveruke;1611632 This subject has been discussed before said:
Thanks for the insight

on :
1. the looks I understand but I am noticing on say a spruce top with a straight grain, it is a two piece top that a the matching is hardly noticed. But there are the other reasons.

2. Don't feel the need to answer this unless you want to (that goes for everyone) but if it gets down to cost effectiveness should a the price be lower or higher considering the wood verses the labor involved ? IF someone is equipped to build both one piece and two piece tops, and has the size of both woods available. (also I don't think anyone has explained the difference with surface area when doubling small pieces yet. Is there really less waste ? We did talk about the width of a saw blade.)

3. wouldn't that be a double edged sword ? couldn't some be stronger on the ends than in the middle while others may be stronger in the middle than on the ends ? Should three piece tops be avoided for this reason ? And there is not bridge on the back, would a 1 piece back and two piece top be better?

4. I don't understand how it makes a more consistant sound wouldn't that depend on "what" you are joining together ?
Click to expand...
 
Last edited:
You must log in or register to reply here.

Similar threads

D
Spruce top book match top
Replies
5
Views
650
ksquine
ksquine
Pissodes
Acquired He Mele Aloha Song Book
Replies
6
Views
134
man0a
M
A
Stumpfs Ukulele Method and Solo Book
Replies
0
Views
73
Alicia6601
A
yolandamusic
My self-published Ukulele Instrumentals book for ukulele groups and teachers
Replies
17
Views
471
yolandamusic
yolandamusic
C
Price Drop Ukelele softcase, strings, strap, book, friction pegs.
Replies
1
Views
256
cogfasser
C
Top Bottom