Suitable plastic for one piece electric guitar.

[dougmurray85]

I'm looking into the feasibility and some suggestions for plastics for CNC routing a one piece guitar (body, neck, and headstock) from a single sheet of plastic. The fretboard and other components are separate.

The plastic needs to come in sheets at least 1235 x 451 x 40mm and opaque in colour.

The attached image is to scale. The strings stretch over 672mm and exert a force of around 70kg, tapering from 75mm at the bridge to 55mm at the nut. The side view has the body at 40mm (up to 50mm if possible) with the neck tapering down to 20mm at its thinnest at the nut. There will be two truss rods to provide extra resistance to the string pull.

Acrylic has been used in the past by other luthiers, but a common complaint is the inferior resistance to buckling compared to wood, even with truss rods adding some resistance.

The weight of the material is not a factor. It would be preferable if the fretboard could be the same material, but I'll source another material.

Cheers in advance.

 

[dougmurray85]

*Edit:

Source another material for the fretboard if the suggested plastics will not resist scratching from nickel and steel guitar strings.

 

[MikeHalloran]

Acrylic is probably the least awful choice, but unreinforced plastic is a terrible material for a guitar neck. It would work okay for an electric guitar's body.

Okay, what about reinforced plastic? Pultruded glass reinforced polyester is used to make chemical resistant floor grating and some similar, straight, products. It's less well suited for a tapered object because milling the taper cuts some of the fibers. You might be able to do a custom layup of a guitar neck by preplacing the fibers in a tapered cavity and then infusing a thermoset resin. Investigate the vacuum infusion process now popular on boat hulls.





Mike Halloran
Pembroke Pines, FL, USA

 

[dougmurray85]

Cheers Mike.

Looks like I'll give up the idea. I wanted to completely skip on molding plastic as the work and cost involved far outweighs the benefits.

My next hair brained idea is bamboo ply. Wish me luck!