Using a 5-string neck for an 8-string build

[treevor23]

Hi, I‘m planning on building an 8-string bass for my senior year project. Initially I just wanted to build the neck myself, but seeing as I have to work on the project outside of school hours my supporting teacher has advised me to not build the neck myself, as it would be very time intensive and difficult for an amateur like me. So I was wondering if I could buy a (ideally paddlehead) 5 string bass head and remake the nut and holes for an 8 string bass.
Now, my question is, would an 8-string bass need the premade 5-string neck to be reinforced (steel or carbon fiber) ? If so, where would be the best place to buy a reinforced 5-string neck?

 

[Gary_M]

Hi, I‘m planning on building an 8-string bass for my senior year project. Initially I just wanted to build the neck myself, but seeing as I have to work on the project outside of school hours my supporting teacher has advised me to not build the neck myself, as it would be very time intensive and difficult for an amateur like me. So I was wondering if I could buy a (ideally paddlehead) 5 string bass head and remake the nut and holes for an 8 string bass.
Now, my question is, would an 8-string bass need the premade 5-string neck to be reinforced (steel or carbon fiber) ? If so, where would be the best place to buy a reinforced 5-string neck?

Hi @treevor23 and welcome to Talk Bass. First of all, I'm assuming you're talking about a double-course 8 string (4 fundamentals grouped with 1 octave string each). If that is the case, you may be able to use a 5 string neck for an 8 string bass and it would likely not require extra reinforcement.

With that said, I think you need to start by acquiring the bridge (or getting the measurements) that you intend to use. Double-check the string spread along with the bridge width, neck heel and nut width. Get a large piece of paper (or use CAD); and physically draw the layout to understand the overall layout and relationship.

Good luck and post your progress here. Lots of experienced builders willing to help.

 

[NedRyerson]

I'm planning out a 5-to-8 conversion project myself. The hardest part was finding a bridge, as they're not commonly made components anymore. I bought the Sung Il BB-208 from eBay.

I'll need to remove the 5-string bridge currently on the bass, fill the screw holes, refinish, and mount the 8-string bridge. I'll also have to plan out the string-through drilling, because the BB-808 is a combo top-mount and string-through.

Then comes plugging the existing tuner holes, relocating new ones, and replacing the nut. Since you're planning on a paddle head, that step won't be necessary, except replacing the nut unless you can buy a neck either without a nut or one that isn't slotted already.

 

[Beej]

@BeeTL is producing an 8 string double course bridge that should be available soonish? I'm not up on the deets, but he's been tagged and I'm sure will pop in with some answers.

 

[BTL]

Thanks @Beej! The 32" scale 8-string conversion necks I'm offering are based on a 4-string design with a 1.75" nut and have carbon fiber reinforcement rods. I haven't formally introduced these yet, but here's a quick photo:

When they're ready, I'll post them in the Bazaar for sale.

Along those lines, and after a quick search, Warmoth offers a 34" scale paddle neck with a 1 11/16" nut and carbon fiber reinforcement rods that gets you into that same ballpark:

For Sale - Lowe Custom Guitars 8-string Bass Guitar Bridge

My 8-string bridge is offered in the Bazaar, here:

For Sale - Lowe Custom Guitars 8-string Bass Guitar Bridge

Other available 8-string bridges are shown below:

Chrome,8 Strings Brass Flat Bottom Base Bridge,BM-108CR-XB-1
Chrome,8 Strings Flat Bottom Base Tail,TS-108CR-XB-17087
Bass bridges > BB 208 1 페이지

Thanks for thinking of me!

 

[Flamingo21]

My 8-string bridge is offered in the Bazaar, here:
For Sale - Lowe Custom Guitars 8-string Bass Guitar Bridge

Until today, I didn't even know TalkBass has a Bazaar.

 

[treevor23]

Thanks @Beej! The 32" scale 8-string conversion necks I'm offering are based on a 4-string design with a 1.75" nut and have carbon fiber reinforcement rods. I haven't formally introduced these yet, but here's a quick photo:

When they're ready, I'll post them in the Bazaar for sale.

Along those lines, and after a quick search, Warmoth offers a 34" scale paddle neck with a 1 11/16" nut and carbon fiber reinforcement rods that gets you into that same ballpark:

For Sale - Lowe Custom Guitars 8-string Bass Guitar Bridge

My 8-string bridge is offered in the Bazaar, here:

For Sale - Lowe Custom Guitars 8-string Bass Guitar Bridge

Other available 8-string bridges are shown below:

Chrome,8 Strings Brass Flat Bottom Base Bridge,BM-108CR-XB-1
Chrome,8 Strings Flat Bottom Base Tail,TS-108CR-XB-17087
Bass bridges > BB 208 1 페이지

Thanks for thinking of me!

Wow, that middle one would be perfect, since I am going for a Black and White color scheme! Would you be willing to disclose how much one of these might cost? Because I am seriously intrigued…

 

[BTL]

Wow, that middle one would be perfect, since I am going for a Black and White color scheme! Would you be willing to disclose how much one of these might cost? Because I am seriously intrigued…

I can shoot you a private message with that information, sure. As far as other options go, Alloy Guitars might be worth looking into. They may have a ready-to-assemble paddle neck that is pre-programmed to suit your needs.

[Invalid or Expired Link Removed]

 

[BTL]

Here's a paddle-head 5-string neck from China with the correct nut width, but it's only 30" scale.

5string Bass Guitar Neck 24Fret 30inch maple Rosewood Fretboard Paddle Head | eBay

If I were to use this neck in an 8-string build, I'd modify the taper so the heel is 2.5" vs 2.75". I was unable to locate anything similar in 32" or 34" scale, but it's probably out there somewhere.

@Ric5 may be able to provide additional insight.