AG09: Fretless 6s with a twist

After much dicking around, rethinking, and not a touch of experimentation, I've finally "decided" on a design for a six string.

+ 35" string length (maybe going to 33"... stay tuned)
+ 80mm bridge (16mm string spacing, monorails)
+ 51mm nut (was 44mm, oops!)
+ single ceramic soapbar passive VT
+ 14" fretboard radius
+ lightweight tuners, individual string bridges (not as shown)
+ laminate body
+ laminate edges (a la M. Lairat's Stega basses)

Materials will likely be rimu and blue gum (for body and laminates), Qld mahogany and jarrah (neck).

The laminating thing is interesting, though a touch tricky with these woods (or is it my complete inexperience with the process? ). First step was building the bending iron. That was cool. Then making molds, cutting laminate pieces, gluing them up, and then cleaning the results. Basically I made the bottom curve as a test piece and it came out pretty well for a first effort (pics to follow). Hooray!

 

Initial work on the edges meant owning a bending iron. Checked YT and decided to make one ($30 or $400? No brainer). It, after a few attempts, came out pretty well. The cartrige heater is a 400W unit and gets insanely hot. I have this thing at around 220C indicated and I am about at a 4/10, so 400W is overkill. At times more is not always better. The body is 2x4 pine, the holding parts ceramic pot stands, and the pipe itself some Al tubing I found lying around stuffed with alfoil. The controller unit I got from eBay and mounted in a jiffy box etc. It works pretty well, though I have nothing to compare it with. Its built big enough so I can play with side bending down the track.

Here is the competed unit with my initial test molds in a half-finished state in the background...



Pot holders doing their thing...



A spring acts as protection for the cartrige wires



and running it up for the first time (temp in deg C )



Time to use it to create the bottom curve for the bass. Using a laminate of rimu and blue gum (floor boards and fence post repectively) to make a 300mm curve, 14mm thick, 30mm wide. I cut five laminate layers of around 3mm on the bandsaw, curved them to basic shape using the iron, then sandwiched them into the mold with copious amounts of Titebond (I was going to use hide glue but forgot), and then clamped it tightly, and left it overnight...



Mostly okay, though I'm going to have to work on my bending some (a few small gaps). The piece came out looking like this



A bit manky, and more uneven than I'd like, but I did make it oversize just in case. Off to the bandsaw, then the spindle sander, and then some light hand sanding and the technique seems to show promise...



This should come up nicely when oiled. Hooray! And it is really strong. I'm going to be monitoring it for movement over the next few weeks to see how the glue and all stands up but I suspect it won't move very much at all.

Making the mold for the top piece will be interesting: It is quite a lot larger, though the curve isn't quite so tight. Still, if this piece is indicative, I may well be doing more laminations as part of future builds.

 

This may be a thing. The woods I'm planning on using are very tough, so I'm not too concerned about meat, but space might be an issue. I haven't got to that stage just yet.

 

Huh. I've seen many folk mention the benefits of a 35" scale for the B but you're suggesting a well-built 34" will sound as good and make the lower portion of the neck more playable? My preference would be for a slightly shorter neck... hmmmm

 

I've just seen that part of your build, @Jisch. That looks really neat. What gave you the idea to go down the steambox route? For me, I have have space issue that rule that approach out, but it clearly works well.

 

Cool! Thanks for the info and I'll look forward to see what you've come up with. So much fun, right?

 

Okay. I can see, and hear, that. Given I am not a fretless player, and I haven't picked up a 6 string bass, I really have no skin in the game so going to 33" might be just the thing. Thanks for the info, @GMC

 

No! Epic fail on my cut-and-paste job! Thanks for spotting the obvious, @Beej. The correct value is 51mm. Doh!

As an aside, I notice you are from Vic. I lived there for quite a few years and miss the place a lot. Where abouts are you located? I used to live on Wark St after giving up a place in View Royal... sigh I still remember the air. It's a magic place...

 

I do miss the place... Oh well, we work with what life gives us. I'm so grateful to have lived there for as long as I did

 

The bending iron is simply another approach to steam bending. I was more wondering about the choice of a steaming box as opposed to the iron or something like a Fox-style bender. Working in a small shop, my choice is more limited by storage space, so I'm using the iron, but that doesn't make it the "best" option. Hence my question