Archtop Construction - Part 1

 I started my archtop build by joining two wedge shaped pieces of European spruce together, traced the guitar outline onto the wood and cut out the rough shape. I used a router to cut into the edge of the top to establish the desired thickness, this gives me a reference while carving the rest of the material away. After many hours of careful carving, measuring and scraping the archtop begins to take shape.

I used a bending mold with a heating blanket to bend my first maple rib. This guitar is going to have a cutaway on the treble side, so a different mold was needed for the second rib. This was my first time bending for a cutaway and I was a little nervous about cracking the maple. I used heat for an extended period of time while bending through the tightest curves, in the end the process was a success. I glued the neck and tail blocks in place joining the two sides together, glued the kerfing in place and the rib structure was complete. 

After carving the outside of the top, I flipped it over and started the process of carving the graduation into the inside. I drilled a series of holes to a depth slightly over my desired finished thickness. I used my gouge to carve away the bulk of material, switching to my planes when I started to approach the bottom of the drill marks. Next, I laid out my f-holes and carved them using a coping saw, knifes and files. 

Once finishing the f-holes, I finalized the graduating to the inside of the top. I laid out three areas of varying thickness and drilled more holes to these depths. I continued to carve until I reached the bottom of the holes and took my time to scrape and sand the inside to a consistent smooth surface. I cut two tone bar braces from Adirondack spruce stock and carved them to fit snugly to the inside arching. I used feeler gauges and chalk fitting technique to get a perfect fit before gluing the braces into place. Once both braces were attached it was time to glue the top to the sides. I did this process by lacing a long bungee rope over the body for clamping pressure.

With the top glued to the sides the next step was to plan and calculate the routing channel for the binding and purfling. I am using an ivoroid binding with wooden black/white purfling, this requires two separate routing channels. I first cut for my purfling using a routing tower, immediately followed by the binding channel. Before gluing the binding into place I routed my pocket for the dovetail neck joint using a routing jig. 

I glued the purfling in place first using wood glue, I used masking tape to keep clamping pressure on it while drying. Next, I used a hot plate to heat the ivoroid binding causing it to become malleable. I bent it to fit the shape of the tight curves through the cutaway portion of the guitar. Once bent to shape I glued it in place using acetone and cyanoacrylate glue. I repeated the process of using masking tape to keep it in place while the glue set. I am very happy with the way the binding job is looking so far, the next step will be to scrape the binding and purfling flush and clean up the glue residue. 

  Im looking forward to getting back to this build after the holiday break! 

- Justin Ness 

Electric Guitar Construction Lab - Part 1

  For the Electric Guitar Construction Lab, I created a blueprint based off a classic Fender Precision bass guitar. I altered the neck dimensions and headstock shape to my liking and made the full scale blueprint with pencil and paper as part of the Electric Guitar Design class earlier this year. 

  I decided to use Alder for the guitar body, and hard maple for the neck. I started the building process by jointing two pieces of 2" think Alder together to give me a blank wide enough to cut my solid body from. I did this by using the power jointer and planer to square the boards, then glued and clamped them together. 

  I made routing templates out of plywood for my body, headstock and control cavity. They were made to exact size by referencing my blueprint, and the edges sanded smooth for routing. Once the body joint was dry, I thickness sanded the body to 1 3/4" and traced the body template onto the blank. I used a bandsaw to cut it out slightly oversize, stuck my template to the top and flush trimmed using a router table. 

  For the neck, I decided to use a piece of slab cut maple that was thick enough to re-saw a fingerboard, giving the appearance of a once piece maple neck. I squared the board, and used the bandsaw to re-saw a 1/4" thick cut off the face to be used as a fingerboard. I made sure to mark the edges of the stock so I could properly alight the fingerboard and neck grains when gluing the pieces back together, making the seam hard to notice. I routed a truss rod slot into the neck stock, as well as two slots for carbon fiber rods to offer further stability to the neck. 

   I cut the fret slots into the fingerboard, laid out the neck taper and planed it to dimension. I then glued the fingerboard to the neck stock and clamped it to dry for a few hours. Once dry, I used my template to cut out my headstock, and used a router to flush trim it to the finished shape. 

  I setup a fence on the spindle sander and used it to thickness the headstock to size, blending the transition to the fingerboard. Using the bandsaw, I removed the excess neck material, and routed it flush with the fingerboard on the router table. I laid out the fingerboard for my position markers and used a drill press to drill the 5mm holes for the round dots. I glued them in place, sanded the fingerboard radius and installed the frets.

  

 The body and neck construction is nearing completion, the next step will be routing the neck pocket and attaching the neck to the body. It's looking like the bass I imagined, and it should all come together soon. 

      - Justin Ness

Electric Guitar Construction week 3-4

It’s been a while since my last post consequentially this blog will be considerably longer than previous posts. We last left off with me gluing my cap on. First I flush trimmed my cap to the body. The next step was to route for my control cavity. I chose to route out quite a bit mainly because the mahogany body I used was very heavy (however the large pocket proved to be useful in laying out electronic components also). I had to do two routes one for the main cavity and one smaller route for my smaller upper cavity.

Then I began construction the neck. Preparing the fingerboard is a crucial step if this is done poorly the whole neck shaping process will suffer. I had to determine the exact taper, width and shape I wanted before I moved on with any neck shaping.

Then I glued on the fingerboard. The first step is to find the center line of the fingerboard and neck and line them up with the nut shelf in the desired location. Then I drilled two holes, one at the 1^st fret slot and one on the opposite side in the 12^th fret slot. Then I coated the bits in wax and placed them in the holes this would prevent the fingerboard from shifting any during the gluing process and it would also make it extremely easy to reposition the fingerboard after applying the glue.

After doing a test run with cauls and cam clamps I taped off the truss rod slot and applied glue to the fingerboard. Then I let it dry for 2 hours before proceeding.

During clamp time I proceeded to do some sanding to my body, everything needs to be sanded out to 240 before placing a round over or routing a pocket for my neck. Any irregularities in the surface can cause problems later on.

After the glue had fully set up I rough cut out my headstock design.

Then placed a template over the head-stock area and used a flush trim router bit to create a perfect copy of my template. At this point i glued on the piece of the fingerboard i had cut off earlier. I then created the traditional fender style “neck scoop” by using a spindle sander and a backing board. To do this I began to sand off material until I got the desired scoop.

After I fine-tuned the headstock I cut off the excess material along the side of the neck and flush trimmed the neck. This is a very scary part of the build because at any point the router can tear out or catch at any point destroying the neck.

I then radiused the fingerboard. I chose to do a compound radius meaning that I would first start with a 9" radius at the nut transitioning into a 12" radius at the heel.

 I the used a hand drill to drill out holes for side dots.

After that it was time to hammer in the frets. I must admit that this fret job was the easiest I’ve done yet. I was so easy because I pre-bent the fretwire perfectly. Because the fingerboard has a radius to it the straight fretwire must be bent, however it must be bent past the radius to prevent a fret from popping up on the sides but not too much or it would pop up in the middle.

Many luthiers choose to glue frets in. A lot of times the glue of choice is super glue or cyanoacrylate glue, I've found that the less I can use of this the better. I chose to use some diluted Tight Bond. I brush glue into the slots and then hammered in the frets.

Then I snipped the frets flush with the fingerboard edge and filed a bevel into the ends of the frets. The rest of the fretwork (Leveling, Shaping, etc.) will be done later.

With the neck being nearly complete I began making a template to route my neck pocket. I did this by double-stick taping straight plywood pieces around the neck heel onto another board. This would ensure the best possible fit. I the rough cut the shape of my neck pocket and flush trimmed the template with the bearing riding on the pieces I had double-stick taped.

With my template complete I practiced a few routes on a scrap board to ensure I had the best possible fit and correct pocket depth. After a successful test route I clamped my template to my bass body and routed out the neck pocket.

Then I laid out four ferule holes with a Forstner bit and followed this step by clamping the neck to the body and drilling for the neck screws.

Since I decided to go with my own body design I could not use a conventional pick-guard therefore I had to make my own. I made a template from my blueprints. With this I bought some pick-guard material from Stew-Mac and double-stick taped it to my template and used a beveled routing bit to cut out the shape of my pick-guard.

 After doing this I drilled and routed for my pickups and tone and volume knobs.

I also had to create a cavity for my jazz style bass pick-up. I did this in a two steps. The first step was to drill each corner of the cavity because of the tight radius required in those types of pick-ups. Then I plunge-routed the rest of the cavity. I then took an extra-long drill bit and drilled a hole form the pick-up cavity to the control cavity.

The bass is really starting to take shape. See you guys for next weeks addition to my electric bass blog.

-John Potts