Making the Solera
Making the solera is probably the most important step in making your guitar. The classical guitar solera is the work-board that the guitar is made on. The solera is what locks in the neck angle and sets the height of the bridge. These two things are crucial to the guitar’s set up. Creating an instrument that both sounds great and is easy to play begins with creating a good solera. The string height on a classical guitar is important for the players technique and sound. Without the proper string height pull-offs are not crisp are the guitar can begin to sound a bit like a flamenco guitar.
To make a good solera you need to fully understand and visualize that the surface of the solera is the exact opposite to the surface of the guitar. Where the guitar slants down the solera slants up and so on. The neck ramp is sloped down from the flat plane of the solera. ON the guitar the neck is titled forward to create the stair case effect described in the page on the guitar’s set up. This prevents fret buzz and string slap.
In the traditional Spanish method of guitar building the sides of the guitar are fitted into slots in the heel block of the neck. In this method the solera is what sets the neck angle. The neck angle is a huge factor in the play-ability of the guitar. If you are going through the trouble of making a guitar – do it right. The quality of your guitar depends on the quality of your solera.
I also offer a class on making a classical guitar solera. Students leave with the solera they create during the class.
How to Make a Classical Guitar Solera
Making the Solera Base
A classical guitar solera base needs to be stable. Since you will have to lug it around your shop it also should be light. I order to get both these things its best to use a 3/4″ substrate of either plywood or MDF. Whatever you use should be flat. Then cap both faces with 4mm thick veneer.
If you break the skin of MDF when carving the lower bout or angling the neck ramp it will become very unstable. To avoid that each surface of the substrate should be completely covered with 4mm thick veneer. This will make your solera very stable. Veneer is not readily available at this thickness therefore you will need to re-saw the veneer yourself.
To make it easier to create your solera you should first create the solera rims as you can use these to both layout and shape your base. Complete instructions on creating solera rims can be found in my book on classical guitar making.
The steps to create a stable classical guitar solera base:
- Using the rims as a template cut a substrate a bit bigger than the desired shape all the way around. Also add a neck ramp that is about 4″(101mm) wide making sure it stops before the nut area (there are drawings for the rims and solera on the guitar making DVD). If you create rims to fit your desired guitar shape they should be about 2-1/2″ wide (63mm) around the perimeter of the body.
- Re-saw enough hardwood to cover both surfaces of the solera and thickness to 4mm.
- Edge join veneer pieces making sure that the resulting panel will be bigger than the substrate base all the way around,
- Glue the veneers to both faces. A veneer press works best. If you don’t have one you will need to rig something up. Make sure you can apply clamp pressure to the middle or you may create a bulge.
- Once the glue dries trim the excess veneer all the way around the perimeter with a laminate trimming router.
- Flatten both surfaces. If you have a drum sander you can run the solera through to get a start. Finish flattening with a hand plane. The entire surface needs to be flat in every direction. You need to end up with at least 3mm of veneer on each face.
- Put the rims in place and and determine the center of the lower bout. Find the center of the neck ramp. Draw a center line.
- Position the template and the rims and drill the two registration holes in the upper bout.
- Reposition the rims, mark and trim the perimeter of the solera base to match.
- Anchor the fingerboard template with pins through the holes in the upper bout.
- Drill the hole in the neck up by the nut.
Making the solera accurate and stable will improve the play-ability of the guitar created in it. The solera will ultimately determine the height of your saddle which will have an effect on the sound of the instrument and how easy or difficult the instrument is to play. So do a good job.
There are solera kits available in the store which include pre-drilled rims, a veneer covered solera base, the softwood patches for the upper and lower bouts and the hardware necessary to put it together.
Laying Out the Solera
The Lower Bout Patch
The surface of the classical guitar solera is the exact opposite as the surface of the guitar. Where the guitar is domed the solera is dished. Where the guitar’s neck angle is forward, the solera is tiled away. This is a very important concept to understand when making a solera.
In order for everything to work together to create the guitar in the book or dvd the lower bout on the guitar should be tilted downward at the butt by 4 mm. There are a other benefits to doing this as well.
To make the lower bout patch you will most likely have to glue up some stock to cover the area. Follow the steps below:
- Cut enough softwood to extend beyond the perimeter of the guitar outline in length and wide enough to go from the butt to about 1″ to 3/4″ below the lower transverse brace.
- Mill the stock to 4mm.
- Edge join the pieces to create one piece
- Locate with dowel pins and glue to substrate
The Upper Bout Patch
Making a solera with an upper bout patch allow you to create a ramp with the correct neck angle right down to the sound hole. This method does not require tapering the underside of the fingerboard. This is the way it is done in the DVD. If you would rather taper the fingerboard as in the book, do not use a patch. Just slope the ramp to the 12th fret.
The purpose of the upper bout patch is to continue the ramp of the neck angle all the way to the edge of the fingerboard just above the rosette. In this way the fingerboard will lay flat along the surface of neck and upper bout of the guitar without the need of relief underneath. This is an elegant solution to the problem of mating these two surfaces. This will also add weight and stiffness to your neck which will have acoustic benefits.
Follow the steps below to create and glue on the upper bout patch:
- Cut a piece of softwood long enough to extend beyond the perimeter of the guitar outline at the upper bout.
- Cut to width of about 6-1/2″ which is wide enough to extend from the upper point of the guitar outline at the 12th fret to the end of the fingerboard at the rosette.
- Mill to .035″ or about 1mm in thickness.
- Mark the bottom most portion of the fingerboard where it touches the rosette on the solera base. This would be the tip on the bass side. This is where the patch stops.
- Mark the other end at the 12th fret
- Cut the patch to exact width
- Glue on the patch using dowels to position.
Trimming the Patches
My solera has rims. The rims help hold the assembly in place during a few crucial stages in making the guitar. Making the solera accept the rims is not a problem. You simply need to trim away the patches outside the outline of the guitar. Once the glue has dried on the patches they can be trimmed with a router to the outline of the plantilla. This way the rims will fit over the outer edges of the patch without being on top of them.
Trace the outline using the registered template. The patches can be trimmed free hand with a laminate trimming router and then cleaned up with gouges, chisels and scrapers to conform exactly to the shape and remove amy residue from the area where the rims go. Once the patches are trimmed its time to shape the patches.
Shaping the Lower Bout Patch
The lower bout is a tilted dome. To dished shape of the work-board should conform to a 25′ radius. The height at the bottom edge of the lower bout is 4mm. the height of the patch at the other end by the lower transverse brace is zero or the level of the solera base. It may actually go a bit below zero in the middle which is ok. The height at the edge of the patch at approximately the position of the front edge of the saddle is 2mm.
Shape the lower bout patch as follows:
To save time first ramp the patch down toward the lower transverse brace with a bench plane. Remember the back edge is already at the desired height of 4mm so no wood should be removed from this edge along the bottom of the guitar outline.
- To save time first ramp the patch down toward the lower transverse brace with a bench plane. Remember the back edge is already at the desired height of 4mm so no wood should be removed from this edge along the bottom of the guitar outline.
- Take a large #3 gouge and begin to scoop out the patch starting in the middle and working out to the edges.
- Once you have approximately attained the proper shape begin to smooth and final shape with the compass plane.
- Check the radius as you go. The radius must be the same in every direction.
- Progress to a curved scraper
- Finish up with the 25′ radius sanding pad
Finish with a scraper and sand paper. The solera should be flat at the lower transverse brace. In essence you will be creating a tilted dish.
Shaping the Upper Bout Patch
The upper bout patch will have its high point where the fingerboard ends on the bass side. This has already been marked on the solera. The patch is .035″high at this point. It taper to zero towards 12th fret, and tapers to zero at the waist. The height of this patch should meet the surface of the solera just before the waist and at the 12th fret.
Imagine that the neck pivots around the 12th fret. It tilts up 2.5mm at the nut and down .035″ or about 1mm at the end of the fingerboard. Hence, the point at the 12th fret stays untouched.
It is not necessary for the patch to come to a point at its highest point, at the end of the fingerboard. This point can be slightly rounded to make it easier to shape the sides of the guitar before assembly.
The upper bout patch should be shaped along with the neck being ramped. That is covered in the next tab – ramping the neck.
Ramping the Neck Angle
The angle of the neck ramp sets the neck angle on the guitar. This is one of the most important aspects of the classical guitar solera. It is also the most straightforward.
Having the correct neck angle to start with is going to make the set up of your guitar go much more smoothly. It will also make it so you won’t have to compromise anything to get the guitar set up properly. The combination of the neck angle, the treatment of the sides in the upper bout to accept the fingerboard, and the tilt and dome of the lower bout will provide an optimal set up if done correctly. It is necessary to get all these things spot on to create a wining instrument.
Follow the steps below to create your neck ramp:
- Mark a line 2.5mm down from and parallel to the edge of the neck ramp just below the area of the nut.
- Begin tapering the neck ramp from the nut end with your hand plane. Plane across the rain and starting at the end since this is where you will remove the most material from.
- Go a little further up the ramp with each pass always starting at the end.
- Once you are getting close to the correct angle plane along the length of the ramp from the end to its high point to make it flat.
- Be sure to check for flat periodically and that the surface of the ramp is perpendicular to the edges of the solera and if not correct it.
- Once you have achieved the correct angle and flattened the neck ramp now ramp the upper bout patch from is high point to zero before the waist.
- When finished replace the center line along the neck ramp all the way to the butt end of the solera.
- Position the plantilla template and drill the registration holes.
- Position the fingerboard template in with the two upper bout registration holes jut drilled and drill the registration hole at the nut end.
- add a cleat to the bottom of the solera. This will provide a gripping surface for a vice or clamp and provide added stability.
For the cleat make sure to use quarter sawn wood and flatten the surface that meets the bottom of the solera. Position the rims and drill through for the bolts. Add the hardware and you are done.
Applying Finish to the Solera
The solera is not complete without a finish. When construction of the solera is completed the entire work board must have finish applied to it. Shellac is an excellent moisture barrier so begin by coating the work board with at least 3 coats of shellac. After the shellac has dried a more durable finish may be applied over it such as varnish. I recommend putting on a top coat finish. Any type of hard,durable finish will do. This will give the work board some protection and also make it impervious to alcohol or shellac which will be used on the guitar while in the solera. If the solera is finished only with shellac any alcohol or shellac that accidentally ends up on the surface of the work board will mar the finish.
Tools for Creating the Solera
Virtually the same tools are necessary to create the back work-board as those necessary to create the solera. If you have all the recommended tools creating the solera will be easier and faster. The short list of tools for making the solera is as follows:
- A 35mm #3 Gouge
- A bench or block plane
- A compass plane
- A curved scraper
- Radius sticks
- Radiused sanding pads
Compass planes are rare. Your best bet is to make one yourself. Its an easy project that will teach you some basic woodworking. There is a plane making dvd in the store that shows you how to make one of these. You can also find plane kits in the store as well. These kits contain all the wood and parts you need to make your plane.
You can also find radius sticks and radiused sanding pads here in the store. The sticks and pads are radiused to the most commonly used radiuses in guitar making, 15 and 25 foot radiuses. These can be used on both classical and steel string guitars. Use these pads to create the solera and back work board as they each have a different radius dome. The sanding pad for the solera can also be used to shape the bottom of the bridge for a perfect fit.