More Detailed Overview of the Soundboard Construction and Tools List

Here's a great and detailed overview of joining the soundboard and bracing it.

What a great resource! He goes through the whole thing in great detail, from examination of imperfections, down to the joining mechanisms. I'm going to take some notes here.

Materials

• A bookmatched guitar top blank. The "top blank" are the two plates that will be joined together to create the soundboard. "Bookmatched" just means that the pieces are mirrored and otherwise identical.
• Yellow glue. I'll have to return to the discussion of which glue is best.
• Brace and patch stock. This is the wood that will make the braces on the inside of the soundboard.
• Assorted cauls.

Tools

• A bench plane. This will be used to reduce the top to the proper thickness and to smooth the joint between the plates for better gluing.
• A shooting board. (See image.) Since I'm not going to be able to afford/house a proper jointer, we'll need a method to create the joint evenly. We'll return to reassess whether we need a shooting board a la Guitarmaking.
• Carpenter's framing square.
• Assorted clamps.
• Razor saw.
• Chisels and (woodworking) knives.
• It seems like having cabinet scrapers will be a good idea, too.

I'm beginning to understand, without ever having touched one in my life, why the planes come in different sizes. The larger numbers seem to be larger and are better suited for larger pieces of wood. Imagine using a tiny, tiny plane on a huge, huge wood surface. It is likely you are going to work unevenness into the wood.

And speaking of bench planes, check out this video about how to use one:

Thinking About The First Steps and Wood Selection

After doing a whole lot of reading, I think it will be natural for me to start with the sound board and back of the guitar. Both the top and back plates of the guitar start with two wooden boards, joined together by glue and the process is similar for each plate.

The other thing about starting with the plates is that it will require a lot of the basic woodworking tools to get going. I'll need glue to join the plates, a hand plane to reduce the sound board to the desired thickness, some sanding materials to smooth it, and a caliper to check the thickness. There are several approaches as to how to afix the plates together. AGB followed Guitarmaking and built a shooting board (first image), meanwhile JSevy (second image) has a neat setup using only a surface, wedges, and cauls (those planks across the top). One thing is for sure, and that is that I'm going to need tons of clamps to perform this gluing operation. When the top and back plates are joined, I'm going to need to cut out the rough shape of the guitar, and this will require either a coping saw or a band saw.

Another thing that I wanted to think about is the wood materials to use. Everyone seems to be using spruce for sound boards, but upon examination of what is available, it seems like there are thousands of varieties and price levels of spruce.

There is an in-depth discussion of sound board wood at Goodall Guitars; the substance here is that Sitka spruce is very strong, with good balance between the frequencies, and is suited for pick-style playing, while Cedar or Redwood is much better (louder) for finger-style playing and is generally less strong.

Stewart-MacDonald has sound board top sets. They come as two pieces, sanded down to .125-.030" (which, I understand from AGB, might be a little too much) each measuring 8.5" x 21", with so-called "master grade" going for about $90. Allied Lutherie also has Sitka spruce tops for about $20 less, as well as more expensive European spruce. I'll have to look into that. Over-all, it seems like spruce is going to be the choice for the sound board.

Now for the back. An interesting note, from a forum, that I found regarding the wood composition of the top and back:

Now, here's the sticky wicket in regards to using tops and backs and sides all from the same type wood. If the top creates a tone or frequency that it resonates at, and the back resonates at that same frequency, you will end up with a cancellation of certain overtones and harmonics. Also known as wolf notes. This happens a lot in violins, cellos, and instruments of that sort because of the constant tone created by the bow and that the top and back are coupled together with a sound post.

So, the wood should be different -- but what kind? From Petros Guitars:

The harder the back wood is, the less energy it absorbs and so the less it vibrates. The less it vibrates the more it projects. The cost of great projection is reduced tonal color as contributed by that wood. Conversely, softer woods vibrate more and produce great tonal color, but project less well.

So, hard back tone woods:

• are heavier,
• vibrate less,
• effectively focus energy to the top and, therefore,
• project powerfully.

Soft back tone woods:

• are lighter,
• vibrate more,
• focus less sound to the top, but,
• contribute to more evocative color and tone.

He also goes on to say that, basically, soft backs shouldn't be paired with hard tops. For Alaskan Yellow Cedar, Mahogany, Koa, Sapelle, and Claro Walnut, don't go above Sitka spruce in sound board hardness. East Indian Rosewood and Sitka are a tremendously popular combination, which naturally turns me off just a little bit. Black ebony sounds exotic and dangerous and is going for about $165 for the set, but I might have to hold off on this decision because strange woods might offer up strange problems when the time comes to bend the sides.