Build #2.5 (8 str. tapping body rebuild, paint, pickguard, aluminum, strangeness, oh my!)

Discussion in 'Luthier's Corner' started by rwkeating, Dec 7, 2020.

  1. rwkeating


    Oct 1, 2014
    This project is a rebuild of the body of my second build (hence “build #2.5”.) Although I had used the design of #1 for #2, I made the body smaller due to the smaller (30") scale length. That was a mistake with regards to ergonomics. It was time to fix this. I hoped to come up with new design elements that I could use going forward. Here is the original #2.


    I took the things that worked on #1 and #4 and tried to combine them while fixing the elements that didn’t work. The new design sure looks strange, but hopefully it will feel good.


    The original neck is a keeper, so there was no need to mess with it other than some very small shaping to blend it into the new body.

    Main Goals:
    • Design a new body (focus on ergonomics) using the good elements of my past designs combined with new elements to make it better. Make a design that is usable for both 34" and 30" scales.
    Secondary Goals (new experiences) :
    • Paint the body (rattle can) going with an unusual (for me) color, and
    • make a pickguard … tort of course!
    Note: I am making these posts after I completed the build since it took so long to finish.
  2. rwkeating


    Oct 1, 2014
    Although I am reusing most of the items that go on the body, I decided to remake the bridge as I used in build #4. You can see the process I used here

    Here is the new bridge for this build. I will replace the split lock washers with flat lock washers as the split washers are causing the bridge pieces to move around and lift up as the nuts are tightened. I’ll have to see how well these new washers work since their design will make it more important to really tighten down the nuts. That is hard to do because the nuts are so close together that it is hard to get any tool on them especially when the bridge is installed and the strings are on the instrument.


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  3. rwkeating


    Oct 1, 2014
    Since I was going to paint the body (and to keep costs down) I chose Poplar wood. I also went with a multi-piece body. Due to the design, that resulted in a 4 piece body.
    Even though these cuts don’t have to be very accurate, I always try and make any cut as accurate as possible just to practice. I haven’t been doing woodwork very long so I still need lots of practice with the basics.
    Here I am starting with the 1st two pieces to be joined together.

    Glued and clamped.

    I had to true up the new “body blank” every time I added another piece of wood. I used winding sticks (still amazed at how such a simple idea works) to do that.

    I need 4 pieces in total (actually closer to 3 1/2.) No need to make it rectangular, so instead of wasting wood, I just used a small piece for the last part.
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  4. rwkeating


    Oct 1, 2014
    I position my paper template in order to mark out the neck pocket.
    … and use my router plane. I did use a forstner bit to hog out more material, but I didn’t at first as I wanted to establish a clean border. Since the end of the neck is squared off and I've done this before, I decided to stick to my same routine and not to use a powered router here.

    I put the neck in place and reset the paper using the neck position as a guide. I then make a center line on the wood. paperForOutline.jpg

    I take a number of measurement and mark out where the bridge goes. Yep, this is a 30" scale instrument. The neck looks long because there are 29 frets (man those upper frets are close together, but then I knew that form before.)
    The distance between where the strings are anchored and the bridge pieces is important as the string I use are tapered and the witness point can't be on the tapered part.

    … and I make sure that is square too. I’ll mention here that I really need to stop anchoring my string like that. I always have to cover up that monstrosity later. I think I came up with a good idea (you’ll see later) but I’d rather not have to deal with it … I am guessing my luck will run out soon.

    Next I'll route out a spot for the bridge and the string anchoring plate as they will be sunk into the body in order to get a low action that is ideal for tapping.
  5. rwkeating


    Oct 1, 2014
    While I still have lots of wood to rest the router plane on, I route out the spots for the bridge and where the string will mount. Once again (as I did for the neck pocket) I am doing this by hand as I've done it before and the routed areas will have 90 degree corners.

    Finally time to use the powered router (that I borrowed from a friend who borrowed it from a friend) to route out the pickup cavity. I made a few practice templates and did a few attempts before doing this on the real body. My only concern was the corners as my router bit had a larger diameter than the pickup corners.

    Template clamped down with enough room to move the router around.
    Ready to go … and with lots of light.

    Because my router bit isn’t the correct diameter, I had to work on the corners. I used a rat tail file for the top (where it needed to be nice and clean) and an old Dremel tool with and even older bit down below to just hack away. Even though I will use a pickguard, I wanted to practice making the pickup route as clean as possible.
    Matt Liebenau likes this.
  6. rwkeating


    Oct 1, 2014
    After deciding where the volume, tone and jack would go, I drilled out small pilot holes.
    Then came in through that back with larger bits.
    Getting ready to free hand route between spaces for wires. I don’t know why I do that. For some reason I don’t want to remove too much wood for fear that any bump will crack the body … not that I go around bumping my instrument often, but still …

    I made a template for the battery box from the same piece of MDF that the pickup template is on.


    Routed out the battery compartment.

    Before routing out for the covers, the cavities looked like this. Don't worry I cleaned them up nicely later.
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  7. rwkeating


    Oct 1, 2014
    With the major routing complete, it was time to cut out the body. I don’t have a band saw so I started by cutting straight lines.

    Then I went to the drill press and drilled all along the outline. This serves as a guide to help keep the edge square as I remove material down to the line. Unfortunately it also results in a bunch of work since you are working on such a rough surface. I did this same thing last time and said I’d never do it again. Lacking any different ideas this time … I did it again. I had to slowly go around with a coping saw.

    This is the ugly mess left behind.

    … but my new favorite tool came to the rescue (more or less) … the Japanese wood rasp
    After I got the sides close to being correct, I drilled tunnels from the pickup to the battery box and from the battery box to the controls. The wires that run through the battery box have their own channel in the floor of the battery box (so they don’t get pinched by the battery.)

    Always a tense time during a build, but it worked out.
  8. Bruce Johnson

    Bruce Johnson Gold Supporting Member Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    That style of bridge, with the saddles floating on a machine screw, can have a lot of problems with buzzes and rattles. Here's a couple of details that can help:

    For the nuts on the back of the saddle screws, use nylon nuts. You can even get unthreaded nylon nuts. When you thread them onto a screw, they form the threads and grip the screw like a locking nut.


    You can also use a standard ESNA locking nut; steel nut with a built-in nylon locking ring.


    Instead of using a lockwasher under the nut to take up the clearance, try a small belleville washer (aka Wave Spring Washer):


    To keep the saddles from buzzing against the bottom of the channel, make sure the holes for the screws are large enough that the saddles can sit flat on the bottom of the channel. The string pressure will hold them down.

    When you make your own hardware, these little engineering details are important.
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  9. rwkeating


    Oct 1, 2014
    That part I already thought of, the others I hadn't. Thanks @Bruce Johnson !
    Beej likes this.
  10. rwkeating


    Oct 1, 2014
    I still had to do the area to sink the control covers in back. I didn’t do that before cutting away the excess body wood so that I could better position the covers to the final body shape. Fortunately I was still able to secure the templates on the shaped body.

    I made a template slightly larger than the battery box for the cover route. For the control cavity, I got away with using the pickup template.

    I made covers out of aluminum. They would probably need to be sanded again to size after the body was painted but that would be easy. Later I would drill holes for the mounting screws and then sand/polish the surface. This aluminum could have been thicker, but it was all that I had. Not shown in this picture is the final work on the covers.
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  11. rwkeating


    Oct 1, 2014
    I tried making a pickguard template in the CAD program Librecad, but it was easier just to use a piece of paper on the body and draw it out. The paper was positioned by cutting out space for the pickup and the neck. Once I had that I made the general shape. I put it on the back of the pickguard material and cut it out leaving an extra amount around the edges.


    I drilled some holes in the corners to make it easier to cut out …

    … and ended up with this.

    The key areas were the pickup and the neck pocket. Since the pickup was surrounded on 4 sides (and the neck only on 3,) I decided to do the pickup cutout first, then fit to the neck pocket. This would anchor the pickguard into position and then I could cut and file the outer shape.

    I put some tape on my pickup router template (to make the area smaller) as I wanted the pickup to fit tight in the pickguard and I would make any adjustments with a file later. resizePUtemplate.jpg

    I routed out the pickup cutout leaving me with this.

    I shaped and cut the pickguard on a type of board I’ve seen other use. You can put a saw blade in the slot and you can use the file in the hole. By doing this you support the pickguard on as many sides as possible to avoid breaking it.

    I used a razor blade to bevel the outside edges.
    I drilled the screw holes and counter sunk them. I went too far, some to the point that you could see the white around the screws. I had no choice but to do them all that way and turn that into a feature. In the end, this is how the pickguard looks.
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  12. rwkeating


    Oct 1, 2014
    Now on to covering up that string anchor monstrosity!
    I thought of making a cover kind of like those on the first Precision basses. I only had the aluminum on hand that I used to make the control cavity covers. It would be easy to bend, but may be too thin. I figured I’d give it a try anyway.

    I made a piece of wood about the size of the string plate. I cut out a rectangular piece of aluminum and then bent it over the wood.

    This is how it would fit over the plate. I didn’t want a tight fit, so this was good.
    I wanted the cover to angle back a bit. I marked where I wanted the bends, clamped the piece to my work bench and bent it with a small rod by pressing down and against the side of the workbench.

    This took more effort than I expected but I worked it until I got it.

    Initially I did a few trial runs bending scrap aluminum then finally did the real thing.

    I made a CAD drawing to get a good look on the ears.

    Marked those off and used a hacksaw to cut away most of the material. Shaped it on the grinding wheel (that saved a bunch of time) and cleaned it up with files.

    I eyeballed it and checked it against the CAD drawing. It came out well. Mounting holes would be drilled later.
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  13. Beej


    Feb 10, 2007
    Vancouver Island
    Fair play! :thumbsup:
    rwkeating likes this.
  14. rwkeating


    Oct 1, 2014
    No matter how much I kept telling myself that successful painting depended on the initial preparation, I still didn’t prepare enough. I did a lot of painting and sanding over and over. Once I even sanded down to the primer.

    I learned a lot, but I also probably forgot a lot due to breathing paint fumes. o_O

    I used Rustoleum enamel primer and Rustoleum enamel paint. Painting outside in the fall left too much junk on the paint. The only covered area I had was the “mud room”. I put up plastic drop cloths, but still got paint on some areas. I put a fan blowing out the door and now the fan is blue. I accidentally hit the door so that it closed a bit in front of the fan. Now the door has blue on it. Oh, and my shoes are a bit blue too.

    I would apply as many coats as possible within the specified one hour window (per the label on the can,) wait 48 hours (per the label) and then sand. I repeated the process over and over. Time dragged on.


    If we hadn’t been going into the cold weather season, I would have probably just started all over. Instead I decided to go with what I had and make the best of it. Not wanting to sand through the finish again (I also had run out of paint) I jumped to polishing.

    I stopped here. :)
    Next: pictures of the finished instrument.
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  15. I once painted a guitar body bright yellow and for months after I kept finding yellow overspray on the oddest things that I thought were tucked away in the garage at the time.
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  16. rwkeating


    Oct 1, 2014
    I tried to do some color correction on the photos. Not sure if it helped show the true color or not.

    Since these pictures were taken, I shortened the strap bar a good amount. That is counter intuitive in terms of how a bass balances, but for the way a tapping instrument is held, this actually improved the balance.




  17. Beej


    Feb 10, 2007
    Vancouver Island
    Outstanding! :thumbsup::woot:
    rwkeating likes this.
  18. rwkeating


    Oct 1, 2014
    Better late than never :oops:. Here is a video demo of the instrument
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