Questions & Answers
This question and answer section is the result of a readers request. The current section includes some questions selected from many sent in since the release of "Classical Guitar Making". There have been some questions that have been asked again and again, some are listed here. The intention is for readers to possibly get immediate answers to questions that are preventing them from going any further in their guitar building projects. I sincerely hope this can be of some help. In the near future this section will be database driven and have questions listed by subject. This was not possible in this update due to time constraints. Scroll down page for more questions.
Solera, Sides Assembly & Neck Angle
On Feb 15, 2009, Peter Franklin wrote:
... "I am not clear about a couple of points - 1 - Is the front assembled and braced on the Solera - your text talks about a workboard but as far as I can tell there is one for the back but not the top. 2 - When assembling the sides to the neck you talk about using a flat surface for this. How is the neck angle set in this case? I have considered using the solera but then the sides would not be level due to the dished section for the lower bout."
 Â<-the reply-> ..."The top can be assembled on the solera. I use additional work boards for tops so that I don't tie up the soleras. The work board is the same as the solera but without the neck ramp. It is also thinner.   The neck is assembled to the sides on a flat board with a piece of wood the thickness of the top glued to its surface to offset the sides from the neck by the thickness of the top. The neck angle is not set here. The neck angle is locked in when the top and back are added on the solera. When the sides are added to the neck, the edge the top is glued to should be flat at this point. It is shaped before you put the top on."
Laminating Sides
On Dec 12, 2008, Roger Foster wrote:
..."I have only one question... I would love to know why you choose to laminate the sides?"
<-the reply-> ..."As far as laminating the sides goes, it was a technique that I brought over from furniture building. I did a lot of shapes in my furniture and mostly used laminations to do them. I am very comfortable with this technique. As for why do it to the sides, there are a number of reasons which I outline in the book. First, you take away a heavy material and replace it with a lighter one so it makes the guitar lighter, laminations are stiffer than a solid piece of wood so it adds stiffness. It also yields a very regular shape from guitar to guitar which give consistency in the volume of the box from guitar to guitar. And combined with shellac on both the inside and out helps to stabilize the sides. It is certainly more work but if you are trying to make a great instrument it is not too much."
Sanding Disks, Laminations, & Wax
On Oct 8, 2008, at 4:10 PM, Lefteris Kalantonis (Greece) wrote:
..."1. I made the sanding discs out of MDF and they came out pretty good. I finished them the way you do, but they changed shape after a few days. I realized it was because I used 19mm MDF, which is too thin for the job. After I saw this radical change, I'm very nervous to build the molds out of MDF. Maybe plywood or a combination of plywood and MDF would be safer?
2. I thought of making the linings by laminating 0.6mm thick mahogany veneer. Could this work?
3. In many steps of the job , you use wax to protect wood from glue. I'm very nervous of doing this because I'm afraid of staining the tender surface of spruce or even cedar. How do you remove the wax?"
<-the reply-> ..."the sanding discs, these are usually made from mdf which is 11/4" thick. In the book I use two pieces of 3/4" MDF glued together which is nearly 40mm. MDF is not very stable especially when you remove the surface layer. Everything you make with it should be heavily shellaced. This will make it more stable.    For the linings you can use .6mm mahogany veneer, yes that will work. You will just have more laminations.    Wax will not harm the wood. It is easily removed with naptha. Just put some on a rag and wipe it off."
Neck & Body Separately
On Sep 27, 2008, Colin Wright wrote:
..."rather than having the neck pass through the top end side in the traditional fashion, is it acceptable to use a "standard" dovetail connection leaving all the heel and top block shapes and dimensions as per the drawings?  This then lets me detail the bindings and purflings onto the body first. I have spent a fair bit of time 'engineering' this joint detail, and I think I would make a better job of it".
<-the reply-> ..."it is perfectly acceptable to attach the neck in the manner you describe, and for the reasons you mention. In fact for a time I did the neck like this to make doing the bindings easier. As far as a joint goes you really don't even need a dovetail joint, a simple mortise will do. I used to use a slip tenon and a mortise on on the neck and the body. This is incredibly strong. The problem comes in creating the neck angle and making the joint fit seamlessly at the same time. This will take quite a bit of time to get right on each guitar so much so that any time I was saving doing the bindings unimpeded I was loosing fitting this properly. If you are going to do the joint this way take your time fitting the neck to assure the proper angle."
Binding/Purfling Cutter Router Attachment
On Sep 14, 2008, Enrico Schiaffella (Italy) wrote:
..."I have been very disappointed with all the methods I used for making binding channels, I found interesting the jig you built for your hand held router. I would like to build one just like the one you are showing. Just I am curious to find out if you think it's really worth building it, I don't seem to recall other people using such a jig. Does it work nicely?"
<-the reply-> ..."The best solution for cutting binding channels is a two piece binding cutting machine where the router is attached to an vertical arm that slides up and down and the guitar is moved under it on a sled of sorts. These types of binding cutting machines are available at luthier supply places, or you can purchase plans and build one yourself.  The binding cutter shown in the book is the cutter I used for a long time until I made a two piece machine as described above. I still use it to cut the small purfling channels on the top and back so I don't have to change setups. This machine will work fine, and it ca be made to be completely adjustable. Some people may be uncomfortable cutting bindings with what is virtually a handheld router assembly, but it really isn't that bad. One thing to be aware of is that it cuts perpendicular to the sides since the handle rides along the sides and acts as a reference. This means that if your sides are not perfectly perpendicular to the top and back everywhere along the perimeter, there will be some differences is depth of your cut as you go around the guitar. Also, when cutting binding channels you must make a few passes. Don't try to cut the channel all in one pass with this setup."
Solera Layout
On Aug 11, 2008, Werner Nel (South Africa) wrote:
Â..."If you can please advise if my understanding is correct? I glue on the 4mm extra wood on the lower boat of the solera and then start carving from the middle outwards after drilling the 2mm hole as a guideline. At the very back it must 4mm higher. Must the sides of the lower boat also be 4mm or must I just gradually level them out towards the transverse brace underneath the soundhole? In other words the solera must be flat from the upper boat and just after the the transverse brace after the soundhole start "climbing" to 4mm at the back or with a 25 inch radius?"
<-the reply-> ..."Your understanding of the solera is almost correct. Try to picture the lower bout as a tilted dome, like the back only not over its full length. It is 4mm high at the butt, and about 2mm high at the sides directly across from the position of the bridge, then becoming level to the surface of the solera at the first transverse brace. Then the top is flat from the first transverse brace at the bottom of the soundhole up to the 12th fret. After gluing on the 4mm wood to the lower bout of the solera, begin to carve out the shape of a sphere tilted forward. The depth of the carving at the center above the position of the bridge should be 2mm deeper than the sides at the position of the bridge so the depth here should come about to the surface of the solera before you glued the wood on it."
ÂMaking Bench Hooks & Shooting Boards
On Mar 14, 2008, Ivan Martirena wrote:
..."one quick question: On the book you talk about the shooting board and the Bench hook, but you don't mention either the material or how to get this parts to be perfectly straight. Planning on starting at least building the jigs before anything else!"
<-the reply->..."The large surfaces of bench hook and the shooting board can be made from anything really. I have used plywood and MDF. Whatever you use it should be flat. The cleat and the stop should be made from a good hard wood however, such as maple. There is no magic formula to getting them straight when putting them together, you just have to be careful. My suggestion would be to cut all the pieces to size, make sure they fit the way you want, apply the glue, use a t-square to set the stop and cleat to perpendicular and clamp in place, then drill for two screws on each piece, countersink and put in the screws. Remove the clamps after a few hours and you should be good to go."
