How to make a mold

  Well, last weekend was pretty productive as well as being busy as usual.  Janice and I went to see The Heavy at the Fineline and they put on a great show as usual; I just wish it weren't at the Fineline as it's a little difficult to move around in the place.  After nursing my hangover away the morning after, I got some solid work on my mold done.

  It took a little work to smooth out the masonite full body template to my standards of matching the plan.  When I initially started making the template, I cut too much out of the cutaway and had to build it up a little bit with some sawdust and CA.  This full body template will become the pattern for the mold and side lamination/bending forms, so perfection is crucial as it determines the shape of the final guitar.  

  When I was going to school in Red Wing, my instructor suggested using an inlay bit set, such as the one at Rockler, to make the outside mold pattern from a full body template.  I had to purchase a separate base for my Bosch Colt palm router to fit the guide bushing, and it was tricky to get it centered on the collet to achieve accurate template routing.  I believe Bosch makes a jig for this, but whether you choose the jig or just eyeballing and checking with a ruler, it is worth spending some time(or money) to get it centered properly.

  The first route done with the bushing around the collar, which offsets the pattern by about a quarter inch or so.  It is crucial in this step that the collar always be contacting the template when the spiral bit is cutting, because this piece will become the template for the first layer of the mold.

   Below, is the template for the first layer of the mold, which is routed with the bushing removed from the inlay collar, leaving a perfect inverse of the original body template.

   After the first routs are made with the collar minus bushing, the remainder of the first layer of the mold can be routed out with a top bearing flush trim bit, or first cut out with whichever sort of coping, jig, or scroll saw etc... that you wish.  I didn't want to cut through the perimeter of the first layer with a band saw, didn't have my scroll saw set up, and don't own a coping saw, so I decided to route it out.  It took some time and I had a close call almost routing into the edge, but taking semi-shallow passes with the router proved to work just fine.

   The next step is clamping the mold layer pieces together and drilling a couple of alignment holes on the outside corners of the mold pieces for dowels, which act as horizontal stabilizers for the mold pieces while they are being glued up.  The first layer of the mold is then pinned to each layer and the outline is traced on each layer to be rough cut with the bandsaw.  The layer pieces are then glued up, one by one, each one being flush routed to the first layer with a flush cutting bit.  I was excited to finally use my new router table and found a solid 1-1/2" Bosch flush trim bit with 1/2" shank at Menards.

   The process is then repeated with 2 additional layers, making a total of 4 layers at a total of around 3 inches.  I then used a compass to rough an outline approximately 2" from the inside edge of the mold and this is cut on the bandsaw.

   All that is left is to clean up the outside edge with various sanders and the like, and separate the mold into two breakaway pieces held together by two toggle clamps like the one below.

  Before making the cuts at the neckblock area and the tail, lines are marked for the cuts.  The headblock area will be cut into where the cutaway meets the neckblock, and the tailblock area will be cut to the same offset of the centerline as the neck area cut.  Before making the cuts, dowel holes will be drilled in the center of the cut lines for dowels, which will be glued into one side of each half of the mold to act as alignment keys for each half of the mold.  I just need to get some lag bolts to attach the toggle clamps and the mold will be good to go.

  I'll leave you with a photo of my dust collection remotes.  Between the remote for the dust collector and having a blast gate on each power tool, operating power tools indoors has become an enjoyable task that I don't have to worry too much about cleaning up after.