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Building an Electric Bass Guitar: Part 6 - Final Details

by Lee Laird

Click on any picture to see a larger version.

CLICK HERE to read Part 1 of the Electric Bass Guitar Build - Design Considerations

CLICK HERE to read Part 2 of the Electric Bass Guitar Build - Creating the Neck

CLICK HERE to read Part 3 of the Electric Bass Guitar Build - Making the Fretboard and Neck from Scratch

CLICK HERE to read Part 4 of the Electric Bass Guitar Build - Gluing the Fretboard, Cutting the Headstock and Installing the Tuners

CLICK HERE to read Part 5 of the Electric Bass Guitar Build - Installing the Frets, Bridge, and Saddles

This is the last part of a multi-part article, relating to building a Bass from my own design. The previous sections are available in the links above, for anyone wishing to either start from the beginning or go back to see what took place earlier. Let's get this bass finished...

As I mentioned last month, the Bass's balance was a bit on the body-heavy side, so I decided it was time to change it. I drew a proposed cut line, allowing me to stand back and assess the visual impact. After tweaking the line a couple of times, everything looked good, so it was time to remove a portion of the body, a little bit behind the back of the bridge. I removed the marked area on my band saw, even though I could have accomplished the same almost as quickly using the bow saw I made a couple of years ago. After the cut, I blended the freshly band-sawn surface into the existing smooth perimeter, using my low-angled spoke shave. This shave is amazing in how it can handle a relatively thick shaving, and still leave a really nice surface. A very efficient tool to have in the kit.

After updating the body of the bass, I sat back with the bass in playing position, and it was obvious the balance adjustment was successful. It can be a bit scary at times, when building an important piece, and you realize some aspect of the design isn't matching up with reality. We can sometimes get too close to our projects, as I likely was with my bass, but there comes a time when either something works or changes must be made. I just tried to look at my situation as logically as I could, minimizing any emotions that might stall my progress.

Now that the body was coming together, I wanted to install some strings so I could see how much material I'd need to remove at both the nut and the saddles, since I expected the playing action to be much too high. After feeding all four of the strings up through the end of the bridge, I was shocked by what I saw. When the strings began to wrap around their respective tuners, and the tension began to push the nut around, I quickly became aware of a major difference between bass strings and guitar strings. Guitar strings are quite a bit smaller in diameter (the thickest is the low E for guitar, and it is around .050" compared to the low E on the bass of .105") and with that diameter differential, comes a whole lot of extra force. Specifically, on the guitar, some designs utilize the ability to have the strings come off the tuner and enter the nut at a small side-angle (e.g. not directly in line with the nut-to-saddle path towards the other end of the guitar). While the smaller diameter strings have an amount of "give", the heavier bass strings have very little, and that was the crux of the problem. The position of the tuners on my bass's headstock fed the strings into the nut with enough of a side-angle to cause disaster, and it was immediately obvious the tuners would not work in their current locations.

After looking at the possibilities, I decided the best choice was for me to turn some plugs out of some cherry scrap I had on hand to fill the tuner holes. This allowed me to quickly create plugs on my lathe that fit the exact size of the holes, and with a known species of wood that can handle the stress. I glued each plug into the holes and left a little proud on both sides of the headstock, which I pared flush with both surfaces after the glue completely dried. I thought about applying a thin veneer to both sides of the headstock, which would easily conceal the change, but I decided I'd leave it as a recurrent reminder for myself. I think I may call this my Frankenstein Bass, as it will have a scar or two.

With the headstock back to solid, I laid out the string paths and offset the tuners to match, while also including half the diameter of each string. This, in theory, should provide the exact center of each string, relative to the anticipated string path. This also required me to revisit the location (up or down, along the string path) for each tuner, to make sure none would interfere with the others. After choosing the best placements, I drilled the new tuner locations on the drill press and then reinstalled the tuners.

The headstock above is already re-drilled and the plugs are very obvious. Top of the
headstock has the first touches of Danish Oil applied, to see just
how much change in color it would make.

It was finally time to again install the strings. This time the strings lined up beautifully with the nut and the bridge saddles, so I put a little tension on the strings to determine how the height of the saddles and nut looked. The strings were extremely high, as I'd anticipated, so I started the lowering process by focusing my efforts on the saddles. I marked the location where each string crossed over its respective saddle, and estimated approximately how much too high each saddle was.

Bass with strings on and lining up nicely

I removed all of the saddles from the bridge, and again took them to my clamping jig. Using a small round file, I made each of the notches at slightly different depths, based on what I saw while the strings were installed. I reinstalled the saddles into the bridge and replaced the strings to see what type of impact the notches made to the string height. There was improvement, but the area closest to the nut was still too high. I removed the nut and marked its base an equal distance up from the bottom. Since the nut was presently sitting properly in its slot, removing the same amount across the bottom should leave the nut sitting squarely in its slot. And it did!

Nut upside down in my vise jig, with line I drew to keep
the bottom in the same orientation

I started removing material from the bottom of the nut, using a somewhat coarse file, making sure to check progress often so it wouldn't get too far out of square. I also kept my hand pressure as even as possible, and waited until I felt the file match the bottom of the nut, before starting any stroke. When I started approaching the line that I drew around the base of the nut, I shifted to some fine sandpaper on a known flat surface. Again, the location where pressure is applied is extremely important, so I focused on centralized pressure and carefully moving straight back and forth. I put the nut back onto the bass and re-tensioned the strings, which showed a very nice improvement in string height. I can always go back and tweak the nut and/or the saddles if it feels like the playing action is still a bit high. At this point though, I'm calling the nut done.

I reattached the strings and noticed the distance between the neck and the strings, close to the nut, was starting to grow as I increased the tension on the strings. This wasn't a surprise since I'd not yet tightened the truss rod, which applies pressure in the opposite direction of the force of the strings, keeping the neck somewhat straight. Changing the truss rod's adjustment in the clockwise direction causes the neck to have a slight rearwards force. If you go too far with this direction of adjustment, the strings will usually buzz against some of the frets closer to the nut. If you experience this, turn the adjustment nut counterclockwise slowly until the buzzing stops. *If you do not feel comfortable with this type of adjustment, take your instrument to your local music store, and a qualified repair person can quickly handle this. After I set some tension on the truss rod, I tuned the strings up to final pitch, which I prefer to use a half-step down from standard tuning, to match what I use on all my guitars. The strings played great, with no sign of any buzzing, so no further truss rod adjustment was needed at this time. The bass sounded reasonably good acoustically, even though it sounded slightly out of tune in the upper registers, which isn't much of a surprise before a complete setup is performed. During a complete setup, along with some of the procedures I've already mentioned, the position of each saddle on the bridge is validated (also know as setting intonation), verifying that each string at the 12th fret plays the same note as when the string is played open (or in other words, unfretted), just an octave higher. If the two notes played are not the same, the saddle must be moved either towards the nut, or away from the nut. Most bass bridges have a screw that feeds through each saddle, and by turning the screw (clockwise moves the screw away from the nut, and causes the 12th fret note to be less sharp, compared to the open note; counterclockwise is the opposite results) you move the saddle until the notes match. One of the best measuring tools to use when adjusting the saddles is a strobe tuner, which has a high degree of pitch accuracy that allows for perfect saddle alignment and intonation. Most strobe type tuners have a jack where either an electric instrument or an external microphone can plug in, while some of these tuners also have a built-in microphone, which is necessary when tuning instruments that are acoustic in nature (e.g. a non-electric piano, a cello, an acoustic guitar). Since the bass doesn't presently have a pickup installed, I used the internal microphone on my tuner. Before I move on, I want to make sure to let you know that you CAN make this saddle adjustment with nothing more than your ears. Your overall results will directly relate to your ability to hear and recognize extremely small differences between the pitch of two notes.

This is the point where I would normally install the electronics, including the pickup, volume control and the output jack. Unfortunately, I am still waiting for these pieces, and I always work directly from the parts in my possession to make sure everything matches for a custom fit. Some pickups are active (which means that they require a 9V battery to operate, and the usual benefit is very little background noise) and others are passive, indicating the magnets in the pickup work without any batteries. I will install a passive pickup on my bass, as I've always been more fond of the tone they provide, but I could swap it out sometime in the future to "test the waters".

Besides deciding on the pickup's electronics, the pickups also come in a few different shapes, as well as heights. Some instruments have extra room under the strings, just in front of the bridge, so a pickup might be mounted so that it just sits on top of the body. On my bass, I anticipate I will need to route at least a shallow opening for the pickup, to make it sit low enough so the strings do not contact the pickup when pressing the string down to fret a note or during the vibration of the string. It might seem that the tension on the strings is so significant that the oscillation of the strings, back and forth, shouldn't really need to be considered. If you set the height of a pickup so the strings just barely clear the pickup, while the strings are at rest, you might be surprised when there is a buzzing sound when you start to play (at least on fretted notes). Some pickups are designed to sort of "float" when installed, as the pickup itself isn't directly attached to the body. These have what is called a pickup ring, which is attached to the body with 3 or 4 screws, and then a long screw is fed through a hole in the ring and into the threaded pickup holes. Other designs are screwed directly to the body, even if they are recessed into a matching hole. You can try both and see what sounds best to you, as there are many players in each camp.

In the cavity I drilled in an earlier process on the back of the bass, I will need to drill a hole through the top. This is for the volume control, and depending on your setup, can have: just the volume control, volume and a tone control, or if you have two pickups there can be two of each control (along with a switch to choose which pickup is transmitting sound). There is one more hole I'll need to drill, and that is for the output jack, which I usually place on the rear of the instrument. The connections I'll make with the soldering iron, are as follows: taking the hot wire from the pickup and soldering it to the left lead on the volume control. The other pickup wire will get soldered to the back of the volume control (or to the third lead on the volume control, and then the control is also soldered so it is against the back of the volume control), which will be the electrical ground connection. A wire is soldered to the center lead on the volume control, and the other end will get soldered to the tip connection on the output jack. Another wire is soldered to the back of the volume control (ground) and the other end to the sleeve connection on the output jack, along with the ground wire that is in contact with the bottom of the bridge. This may sound somewhat confusing, and if you don't care to install the electric portion on the bass, again a trip to your local guitar repairperson is a valid way to handle this work.

I always test my instruments with the cavity cover left off, so I can validate everything is functional before closing it up. I usually make the cavity cover out of a rigid plastic, and have used a clear plastic once, which allowed me to see through it to determine how large I should make it. This was somewhat helpful when I changed the design of the cavity on my Les Paul, so I could make room for other electronics. I pre-drill the holes in the cavity cover, so they will sit flush or slightly below the surface. I then use the cavity cover as my template to create a matching recess in the instrument back, and also to mark the exact location for the screw holes. The last step is to paint the clear plastic, unless you like the visual aspect clear provides. ***(I plan to write additional information regarding the actual pickup install, after I have the electronics in possession. This will be on my personal blog: Leelairdwoodworking.com . Feel free to check into my blog in the not-too-distant future, if you are interested in that type of further information.)

Now that the intonation is set, the bass sounds like it is supposed to sound, while playing all over the fingerboard. During this playing, to make certain all was right, I became more aware of an issue I'd noticed earlier, but was now pushed into the spot light. The lower cut-out area I made, on the thinnest-string side of the bass, wasn't pronounced enough and the interaction between it and the heel of the neck needed some help. As there was a fair amount of wood I decided to remove, I started by using some of my full-sized Swiss carving gouges to rough out both the cut-out and the heel of the neck, and then followed with my Auriou rasps (#9 and then #15) and then sandpaper in a range of grits.

Still working to remove material from the side of the neck
and in the cutout, so playing will be easier

This allowed playing on the highest frets with much less contortion than I originally experienced. Just remember to take this type of removal slowly, making sure not to work against the grain's direction, especially with the gouges. Also, I ratcheted my movements down even further, when I was getting close to the fingerboard intersection. This area can be very hard to repair, if you take a big gouge out of the edge of the fingerboard, or you hit this area with a coarse rasp.

I thought I might try leaving the surface on the bass's body, directly from the spoke shave and/or plane, as the clarity and glow is top notch. Unfortunately, there were some small areas that I just couldn't quite get to behave, so in the end I sanded the body, neck and headstock. I sanded from 120-grit up through 220-grit, stopping at that level to apply some Danish Oil.

The headstock and the horn on the lower section of the
body are showing how the rest will look after the Danish Oil
is applied. The headstock veneer is curly Cherry
and the body Mahogany

I drilled and attached the two strap buttons, one on the upper horn and one at the center portion on the rear edge of the body. I like to use the buttons that lock the male section, that is pre-attached to the guitar strap, once it is inserted. There is much less chance that the strap can accidentally slip off, and have your important instrument possibly crash to the floor.

When I originally started this bass, I wasn't quite sure if I wanted to spray a Nitro finish on my bass, like I did on my Les Paul, or go with an oil/varnish blend. I chose to use Danish Oil, as it soaks into the wood, and depending on how many coats are applied, can range from warm to somewhat glossy finish. I applied the Danish Oil somewhat liberally, wiping off any excess with a dry rag, and making sure to let it sit until it was dry.

Body of bass while the second coat was drying.

After the second coat was dry, I went back and lightly sanded with 320-grit sandpaper, which knocks down any little dust nibs. I decided to sand up through 800-grit and then applied two more coats of Danish Oil (the oil-application portion is something I do, even if I had stopped at 320-grit). I find the Danish Oil I applied earlier seems to act like it locks the wood fibers together, so the subsequent sanding with finer grits works faster and more efficiently (you really don't need to do much more than a light sanding with the finer-grit paper held around a felt block, touching all of the surfaces). The "locking wood fibers" aspect may be a figment of my imagination, but it has worked well every time I've tried, and on every species of wood on which I've applied it. You will noticed the Danish Oil doesn't penetrate as much, after the finer-grit sanding. With this, don't apply the Danish Oil too liberally (almost sparingly is best, while ensuring you cover all the surfaces), but make sure to check the wood after it sits for a few minutes. Some areas of the bass absorbed the Danish Oil much more readily, so I reapplied to those areas, until all areas are no longer accepting oil. Using a dry rag, I wiped off all of the excess finish, and again checked it after a couple of minutes. There were a few spots that released some more finish, after the short wait, and I repeated this a couple of times until there was no further signs of excess oil. After the last coat of Danish Oil is completely dry, I'll likely apply a nice high-grade wax, which is something I've used often on this type of surface. While I love the wax on furniture and boxes I've made, I'll have to see if this also works on my bass.

The back of the bass after sanding up through 800-grit,
just waiting to finish drying, so it can get some wax

This photo shows the heel/back connection and up the neck. So close to dry

The finish on the bass is taking a little longer to dry than planned, as we have higher humidity right now. I bought fresh Danish Oil just before applying it, to make sure I didn't use an old mix that might not ever cure completely. Now is the time to be patient. After the wax is on and buffed, it'll be time to again install the hardware and play it acoustically until the electronics are here.

Thanks to everyone that followed the build over the last few months. It was a great deal of fun and pressed my skills in an enjoyable way. If you've ever thought about building a guitar or bass, now may just be the time. Please let me know if you have any questions or comments.

Lee Laird has enjoyed woodworking for over 20 years. He is retired from the U.S.P.S. and
works for Lie-Nielsen Toolworks as a show staff member, demonstrating tools and training customers.
You can email him at lee@lie-nielsen.com or follow him on Twitter at http://www.twitter.com/is9582

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