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The most reliable way to craft uniform and consistent guitars is to use a body mold.

These are made from MDF or plywood, and they allow the body to be constructed in a specific space. All guitars exiting the mold will have the same body shape, as well as have sides that are a perfect 90 degrees to the top and back plates. This makes for an easier time working on the guitar, as well as a better looking and sounding guitar in the end.

The mold itself is fairly simple to construct, and can be done very quickly if a router or router table is available in the shop. The outside mold is a set of stacked MDF pieces or plywood pieces that have half the guitar profile cut into them. They are stacked and screwed together evenly, and allowed to open with a hinge on one end and a draw catch at the other.

When building the guitar, the sides are bent on the pipe and then clamped into the mold where they will cool. Since they are clamped to the same shape as the mold, which is also the same shape they are bent to, they retain that shape very well. Also, since the sides of the mold are 90 degrees to the faces, the sides themselves are perfectly straight and even all the way around the piece. This is hard to do without a mold, especially when gluing everything together. It is far

too much to have to monitor when also trying to get a hundred clamps in place before the glue sets up.

The mold itself can be made from MDF or plywood, though MDF will be better because it is softer on the guitar sides and easier in general to shape and sand. Also, it will never warp, bend, or twist with humidity changes in the shop. Plywood has similar properties, however the clear advantage goes to MDF for the softer edges and the fact that it is manufactured dead flat.

Two pieces of MDF that are 3/4" thick and measure 2' x 4' will be needed, one for each half of the mold. These can be found in any hardware store, and are a little more expensive than plywood, but well worth the difference. This mold will be in use for as long as guitars are being made in the shop, and will never need replacing unless built poorly.

Rip off several pieces on the table saw that are 24" long and just a fraction under 9-1/2" wide. There should be just enough waste left at under 9-9-1/2" to get 5 pieces plus blade waste out of the large piece of MDF. Do the absolute best to keep the pieces as straight as possible through this process, because they will need to line up well when they are assembled later on.

Angled cuts and poor cuts will not line up well, and the mold will look rougher than it should.

If making a mold for a thinner guitar, only 4 pieces will be needed on each side, however a full bodied dreadnought can have up to 5 pieces which will total a height of 3-3/4" for the mold. Look at the individual guitar being made, and build the mold so that the total thickness is 1/2" to 1" less than the thickness of the guitar at the shoulders. This will allow an area that can be planed down when the back is tapered.

Begin with one of the pieces and draft the half profile of the guitar onto it. Follow an existing plan and trace that half image onto the wood, or simply measure out a guitar and draw the shape by hand. The advantage to this kind of construction is that only half of the guitar shape will need to be drawn, as the rest will be duplicated from this main piece. Even if the shape is drawn by hand, the other half will be an exact reflection, and therefore look even and symmetrical.

Bring the piece to the band saw or the jig saw, and cut as close to that line as possible without going over it. Be careful when making this cut, and be sure not to deviate from the line at all. Take the time to make the cut well, because it will reduce the amount of time that will have to be spent sanding and refining the shape later, which will need to be done before the rest of the pieces are duplicated.

After sawing, bring the piece over to the bench and use a curved sanding block to bring the wood right to the line. MDF is much easier to sand than plywood, which is another great reason to choose it for this project. Pay attention to the angle of the block while sanding though, to ensure that the edges are kept at 90 degrees. If the guitar profile is beveled at all, the mold will not be as functional when the pieces are stacked up.

Once the profile has been sanded, blow off the sanding dust and check that all saw marks have been removed by the sander. Go over the areas that need attention again, using long strokes that will blend these areas rather than dig them too deeply.

Spend some time on this master board, as it will directly determine how the rest of the pieces will look, and subsequently the mold itself. A few extra minutes sanding and shaping will pay off dramatically once the mold is made. This will essentially be the template for the rest of the mold, so make it perfectly and the mold will be perfect as well.

Use the master board to trace the side profile of the guitar on to every one of the pieces that were cut out earlier. Make sure to line the edges of the pieces up well before marking them, as this will be important later.

Cut out the center sections on the band saw or jig saw, leaving 1/8" - 1/4" of waste remaining to be removed. The goal of this cut is to remove the bulk of the waste rather than actually cut on the line.

Once all the boards have been cut, screw the master board to one of them, making sure to line up the edges well as before. The screws are temporary, and serve only to hold the boards together while being routed. A flush trimming router bit can them be used to follow the master board as a guide and duplicate the profile on the other board.

Unscrew the master board and fasten it to the next piece with screws. Route it as well with the flush trimming bit, and repeat this procedure until all the pieces have been trimmed.

Stack up 4-5 of the pieces per side, and even their edges well. If the edges were evened out each time as described earlier this should also line up well at this point. It is more important that the insides cut with the router line up better than the outsides, so check this area thoroughly after squaring the edges.

Once satisfied with the stack, check to see that the profile area is 90 degrees to the workbench with a square. If it is, clamp the pieces hard to the bench and begin screwing them together.

Looking at the picture above, a pair of wood screws placed at the neck area, waist, and tail block area will do fine to keep the mold from separating during use.

Repeat this procedure on the other side of the mold, checking for square constantly and making sure the pieces are aligned well. Once correct, clamp them to the bench and screw them together.

Place the two halves together to form a guitar shape in the middle, and line them up

evenly. On the tail end, screw a large hinge, which will allow the mold to open when needed.

This hinge needs to be a heavy duty hinge with thick screws. If the screws that come with the hinge are wimpy looking, buy new screws from the hardware store before leaving.

On the other side, purchase a draw hasp which will be used to quickly lock and unlock the guitar mold. A draw hasp is the mechanism used to close and open most older tool boxes that were still made of metal. A metal bar flips over a catch and a piece is pressed down to apply tension between the top and bottom of the hasp. This tension holds the pieces together in the same way the lid of a tool box is held down. Sometimes they are hard to find, though they can always be purchased online.

At this point the mold is complete, and can be left unfinished or coated with a light layer of varnish to help preserve it. Unless the MDF gets soaking wet, it will not have any problems if it is left unfinished.

The only down side to a mold is that a different one will be needed for each body style of guitar made in the shop. Since they do not take too long to make however, the time spent is well worth the benefits it will provide. Being able to reliably make guitars with straight and even sides and a dead on profile shape is definitely worth taking a couple hours and making a mold.

All the molds in the previous pictures with the exception of the one directly above are for a 16" dreadnought shape. The picture seen above is a smaller 15" Orchestra Model shape, with a removable cutaway insert. These molds are all flat, and store easily below the bench stacked like large books. When a particular guitar is to be made, the proper mold is retrieved and most of the body construction takes place inside it. They are a great item to have in the shop, and will help produce great guitars.