THE MATTINGLY-STYLE MOLD AS TAUGHT BY KATHY WINGERT TO DAVE SKOWRON
To make these molds you are going to need a bandsaw with a blade thin enough to make the radius cuts, and you will need a spindle sander, preferrably of the oscillating type such as the Delta BOSS unit.
For materials you 5 need pieces of particle board which are 18x22 inches and another piece which is 26x22 inches. They need to be big enough to have the entire outline of the body fit plus about an inch all the way around. You also need a pair of steel straps and some 1/4-20 nuts and bolts. You also need a half-template of the shape of your guitar to use a a tracing guide.
Glue the five smaller pieces into stacks of 2 and 3 pieces. Once you have the stacks glued up, trace the outline of your guitar on one of them and then trace again only this time make that outline about a half-inch bigger all the way around. The way we did this was to use a little wooden tool that Kathy had previously made which has a hole for a pencil a half-inch from the end. The tool is shaped somewhat like a bell. (See pic). Now, take the stacks and place them on top of each other and square them up and clamp them together. You want to drill a 1/4" hole in a few places around the edge inside the perimeter of the outline of your guitar, going all the way through the stacks. Dowel them together.
A Copy of Kathy's Tracing Tool
Cut the outer outline very carefully on a bandsaw. Again, this outline will be a half-inch larger all the way around. Once you get them cut, use the spindle sander to true them up. Now, take them apart and center one of them on the larger piece of particle board you cut and clamp it down. Drill through the indexing holes and through the large piece. Now you should be able to sandwich the large piece between the two stacked, oversize outline pieces, and drive a dowel through each hole in the assembly. Now you have the basic mold but the larger piece needs to be shaped and the inside still needs to be cut out.
To shape the larger piece, Trace the outline of the upper and lower bouts and make these tracings about three or four inches larger by indexing the little tool you made on the opposite end from the pencil. Connect the ends of the lines with a straight line and you have the shape of the middle piece of the mold. Disassemble everything and cut out this shape on the bandsaw and then dowel everything back together, but this time you want to glue the entire thing together. Glue it good. Let it dry.
Once it's dry, bring it to the bandsaw and carefully cut straight through the center of the assembly till you reach the remaining outline you drew earlier. follow this outline to cut out the inside of the mold. You will be removing about 75 percent of the material. You can hog out the inside by whatever means necessary if you want. This will make the assembly easier to handle while you're making that precise cut around the middle. It will be quite heavy before you start. If you like, you can plan on saving some material from the cut here to use for your spreaders. Note that you will not be cutting through the bottom of the mold. This mold does not separate into two halves as do other designs.
After you get the inside cut use the spindle sander to true it up. This is the most critical area of the mold so you really want it to be perfect. The outer cuts you made aren't extremely critical. If you cut too deep into the side you can use Durham's Water-Putty to fill the low spots. Bondo would work also.
Take a pair of steel straps and mount them as shown and you're done. Mine are not bolted together in this picture. A pair of bolts goes through two of the holes on either side of the cut. Bolt this together when you are using the mold. Remove the bolts so you can get the sides out of the mold.
Steel Straps
You can opt to put a few coats of varnish on the mold if you like. I was thinking about fiberglassing mine since I used MDF rather than particle board. You see long drip marks on my mold in the picture above. This is super glue that dripped as I was gluing some of the laminations that had separated because I didn't do a good enough job of gluing all the pieces together when I made my stacks.
You can opt to mount clamps or whatever else you need on the mold. I made some fixtures which hold a pair of cam clamps on the mold, one at the neck block and one at the heel. I use these to hold the plates against the blocks when I clamp them on the go-bar deck. You can also mount eylets or other holders if you prefer to use the roping method to clamp your plates on.