https://www.youtube.com/watch?v=MirwxiV ... e=youtu.be
He struggled greatly trying to get the aluminum to "stick" to the acrylic trying epoxy and eventually just screwed it down from the top which I wouldn't like at all. Don’t like the screws through the top of the fretboard. I think cutting on a CNC, it would be easy to cut a dovetail lengthwise and opposite on the neck. Slide on from the headstock side. One screw behind the nut keeps the neck in position.
Here is my idea drawn out rough in Corel Draw for the neck cross section at the 12th fret. These dimensions are for an Ibanez GWB-35 because I had them. Width, radius etc.. I don't know about the truss rod inside, I just guessed.
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I also got curious about the hardness of aluminum vs ebony or some other wood for a fretless fretboard. Looked up the "hardness" on Aluminum. Hard to compare to wood because there is no "Janka" scale on Aluminum, but someone has done the comparison on the Brinell Hardness chart. Australian Buloke is the one of the hardest woods around and has a Janka of score of 3,760 lb, its BHN score is 11.48. Pure aluminum is 15 BHN and hardened AW-6060 aluminum is 75 BHN, Even mild aluminum would make a harder fretless neck than most woods. I have a bass with a Panga Panga neck which is only 1,640 Janka. For reference, a favorite for fretless necks is Gaboon Ebony at 3,080.
I wonder if you had a AW-6060 Aluminum neck with round wounds could you get a good Mmmwah, or would it just sound like it was on frets?
Copper is 35 BHN and would make an awesome looking fretless neck and probably 4 times harder than Ebony.
Copper gets this green oxidation with age. I kinda like the green oxidation. With the string wear under the strings and the green oxidation between, it would look incredible on a relic-ed bass. Think P bass with a grey primer, black undercoat and a seafoam top coat then relic-ed so that you could see through in wear spots and the oxidated neck.