Carbon fiber, 3d Printing, Styrofoam, Surfboards, and Balsa wood.

I don't know about you guys, but I like my instruments made from wood It's nice to have new technology and stuff, but I still like to have (and make!) my instruments in wood...

 

I'm pretty sure that you wouldn't get an acceptable surface finish.
Molds are perfect and repeatable. Vacuum bags are not.

 

I've made cf necks with foam core. Here's the latest. I use truss rod for adjustment.



With vacuum bagging over a core it's pretty difficult to get that cf looks with perfect twill weave. That's why I painted this bass. It also has cf skin over alder body.

 

Great looking bass MPU! I was wondering, how much does it weigh?

 

I've done it to an extent before, however it was a timber neck through with surfboard foam and carbon fibre for body wings.

I had a pretty good local surfboard maker do the glassing for me, as I had no experience with it before. Weather wasn't fantastic when I had it done so there a was a little bit of top coat sanding that I had to do for it to be nice and level.

One thing I learned is that complex body shapes do not lend themselves well to the process, and I would recommend a design that uses broad curves more to make the layup easier. Horns are particularly tricky to get around.

Despite the timber neck, it really has that Steinberger sort of sound to it, and is light as a feather. I'm quite fond of the instrument and won't ever be getting rid of it, but it was quite an experimental idea and I'm happy to have done it, but I won't be making another

 

Vacuum bagged carbon or glass fiber does not nessessarily need a lot of sanding if done properly. Using cloth instead of mat, using continuous pieces of cloth and carefully laying the cloths over core are the key to only little sanding. And of course you have to lay the release film and bleeder cloth so that there are no wrinkles. I also use heat gun and heat the bagging film while applying vacuum to make sure that the bagging film follows the shape of the bagged item.

 

I have not weighted the bass yet. Carbon fiber neck is not lighter than wooden neck, especially if there are wenge or other heavy woods used. Body weight is the same as an alder body.

 

As a guy who has worked with the surf industry before and is a fan of carbon fiber I dig this thread.

 

Flameworker,Try using Armalon on the sufrace. It will leave behind a textyre but it's easier to sand than wrinkles. Are you using Epoxy or Polyester resin ? Some foams and Polyester dont like each other and the resin will dissolve the foam. Many years making surfboards[Poly/Epoxy],off road race car bodies,CART race cars,Aerospace parts/molds[F-18 , B-2 ,F-35 ]Snowboard,windsurfers,E,S glass,kevlar,carbon fiber

 

Polystyrene (Styrofoam) is not compatible with polyester resin (usually used for fiberglass), but epoxy can be used with it. Better to just use polyurethane foam anyway, and either resin can be used.
As noted above, cloth can give a better texture with less sanding, but it doesn't conform to compound curves as well as mat, altho it is stronger for same thickness. There's also 'fab-mat' that is cloth on one side and mat on the other, but adding layers increases the volume of resin used, and adds weight. The idea is to fully saturate the cloth/mat but use the least amount of resin.
Also, if using a porous form/substrate, pre-sealing if with resin will prevent 'starving' of the cloth due to the resin soaking into the base.

 

Carbon fiber cloth conforms pretty well. I used biaxial cloth for all but the top layer. Headless neck is perhaps the easiest shape to make as it's basically a piece of tube. For a whole bass negative mold is the way to go.
I've used only epoxy resin on my basses as I can't stand the smell of polyester resin. I've had enough of that in my younger years when working with boats.
Vacuum bagging with perforated release film and bleeder cloth is a great way to make a laminate that has just the right amount of resin for the cloth.

 

I used to use polyester[surfboards/off road car bodies] but got into aerospace and it's been pre-preg ever since. Well I did do a number of surfboards/windsurfers and a TON of snowboards with epoxy. The OP said something about "negative molds" and pre-preg is the way to go for that,autoclave curing is best however oven curing can work....plus you generally have up to 240 hrs of "out time" before the PP will cure on it's own ,helps with odd shaped cutouts and shapes.You can cut it to fit,taking care NOT to do too many splices in the exact same spots.

 

Prepreg would be the way to go but lack of autoclave or oven makes air temperature curing epoxy more diy-able solution.

 

There are a # of new prepregs that supposedly cure in a bag at room temp,and are just as strong as AC cured laminates,but I havent worked with any yet .