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LewsTherin · 05-05-2006, 12:20 PM

Manufacturing Parts Using Composites

Okay, now that we know how to do the easy stuff (necks, lol, and I KNOW ITS NOT FINISHED YET SO DEAL), we can get to the exciting stuff; making bridges, nuts, tailpeices, pickguards, cavity covers, knobs, etc.

Pickguards/Cavity Covers

These are the really easy ones. They're flat. They're not structurally important. And, you can do just about whatever you want with them.

For this section, materials we will need:

BASIC COMPOSITE STUFF
-Carbon fibre (you can also use fibreglass, or kevlar b/c they look different)
-Plastic (epoxy or polyester, whatever)
-Scissors (for cutting raw material)
-Disposable foam brushes
-Mixing cups and stirrers
-plastic squeegee
-plastic wrap
-Masking tape
-Rubber gloves (this stuff is sticky as all hell)
-Acetone (only thing that'll clean it up. Acetone stops the epoxy reaction in its tracks.)
-Rags (to use with acetone)
-Newspaper and cardboard (to create disposable work space. You DONT want to get plastic resin on your moms carpet)
-Some additives, maybe, if youre using epoxy. Hi-Density filler is a good one if you want to put a screw/other peice of metal in. Colloidal Silica is good for stopping runny epoxy. Aluminum powder is good for added UV protection. (UV is epoxy's archnemesis, btw).

OTHER STUFF
-Dremel
-Drill
-Sandpaper/steel wool
-GOOD respirator
-Eye protection

Okay, so heres the plan. First, you plan out what shape you need. Then, you cut out said shape once, twice, thrice? Its up to you. A single layer is a bit thin. Or, you can cut it out once, then use random little peices to create a funky design with the grain (carbon fibre has a sort of checker pattern to it. It also comes in twill). Whatever, its your pickguard.

Note, Id recommend cutting out a shape thats bigger than what you think you want, casting it in composite, then sanding/shaping it down. Its easier to take stuff off than to put it back on.

Next, lay down some plastic wrap, and tape it down (so it stays down). Mix up some resin. Take your first layer, wet it with resin, plop it down on the plastic wrap. Do the same with your next layer. Make sure they line up and whatnot. Smooth it out with the squeegee, make sure there are no air bubbles.

Like with the neck, you can do like 3 layers at a time. Depending on the hardener you use, epoxy takes either about 8 or about 24 hours to set (when with carbon fibre or whatever). It takes either about 15 or about 30 minutes to set in the pot. Work quickly.

Once the material has set, its now time for normal stuff. Don your respirator and eye protection, fire up the tools, and finalize the design, as well as putting in holes for pickups, screws, etc.

Tailpeices

Okay, so most basses dont have tailpeices. But, maybe youre building a custom bass, and want to use a tailpeice/bridge combo (think, upright/violin style). Now these ARE structural parts, so youll have to pay more attention to the grain on your reinforcing material. This is relatively advanced work.

We'll start with a flat, rectangular peice for our example.

These are the directions the grain should be in (Since its a weave, it actually goes in two sets of directions, front back left and right).

To make this peice, we will start with five (5) layers of cloth, 3 longer and 2 shorter. They will be stacked up L/S/L/S/L. The short peices should be about 1.5", the long ones about 2". The extra half inch on the long peices will be folded up to create the front of the tailpeice.

We will need a mould with a square corner. Two (2) peices of wood glued together will work fine. Now we will:

-Saturate the first layer, fold the last .5" over the corner of the mould
-2nd layer, no fold.
-3rd layer, fold
-etc, until the 5th layer.
-Let this set. Once it does, take it off the mould. You should have a rectangular base with a 90 corner going up (looks kinda like a standard fender bridge, backwards).
-Cut strips of cloth to go on the back of the folded up portion.
-Add these 3-4 at a time, until the folded portion is about 3/8" to 1/2" thick.
-Drill holes for strings and screws.

(UNDER CONSTRUCTION, BBL)

05-05-2006, 12:20 PM	#7
LewsTherin MX Warwick Club HUZZAH! Join Date: Oct 2004 Location: CMass USA Posts: 8,590	Manufacturing Parts Using Composites Okay, now that we know how to do the easy stuff (necks, lol, and I KNOW ITS NOT FINISHED YET SO DEAL), we can get to the exciting stuff; making bridges, nuts, tailpeices, pickguards, cavity covers, knobs, etc. Pickguards/Cavity Covers These are the really easy ones. They're flat. They're not structurally important. And, you can do just about whatever you want with them. For this section, materials we will need: BASIC COMPOSITE STUFF -Carbon fibre (you can also use fibreglass, or kevlar b/c they look different) -Plastic (epoxy or polyester, whatever) -Scissors (for cutting raw material) -Disposable foam brushes -Mixing cups and stirrers -plastic squeegee -plastic wrap -Masking tape -Rubber gloves (this stuff is sticky as all hell) -Acetone (only thing that'll clean it up. Acetone stops the epoxy reaction in its tracks.) -Rags (to use with acetone) -Newspaper and cardboard (to create disposable work space. You DONT want to get plastic resin on your moms carpet) -Some additives, maybe, if youre using epoxy. Hi-Density filler is a good one if you want to put a screw/other peice of metal in. Colloidal Silica is good for stopping runny epoxy. Aluminum powder is good for added UV protection. (UV is epoxy's archnemesis, btw). OTHER STUFF -Dremel -Drill -Sandpaper/steel wool -GOOD respirator -Eye protection Okay, so heres the plan. First, you plan out what shape you need. Then, you cut out said shape once, twice, thrice? Its up to you. A single layer is a bit thin. Or, you can cut it out once, then use random little peices to create a funky design with the grain (carbon fibre has a sort of checker pattern to it. It also comes in twill). Whatever, its your pickguard. Note, Id recommend cutting out a shape thats bigger than what you think you want, casting it in composite, then sanding/shaping it down. Its easier to take stuff off than to put it back on. Next, lay down some plastic wrap, and tape it down (so it stays down). Mix up some resin. Take your first layer, wet it with resin, plop it down on the plastic wrap. Do the same with your next layer. Make sure they line up and whatnot. Smooth it out with the squeegee, make sure there are no air bubbles. Like with the neck, you can do like 3 layers at a time. Depending on the hardener you use, epoxy takes either about 8 or about 24 hours to set (when with carbon fibre or whatever). It takes either about 15 or about 30 minutes to set in the pot. Work quickly. Once the material has set, its now time for normal stuff. Don your respirator and eye protection, fire up the tools, and finalize the design, as well as putting in holes for pickups, screws, etc. Tailpeices Okay, so most basses dont have tailpeices. But, maybe youre building a custom bass, and want to use a tailpeice/bridge combo (think, upright/violin style). Now these ARE structural parts, so youll have to pay more attention to the grain on your reinforcing material. This is relatively advanced work. We'll start with a flat, rectangular peice for our example. These are the directions the grain should be in (Since its a weave, it actually goes in two sets of directions, front back left and right). To make this peice, we will start with five (5) layers of cloth, 3 longer and 2 shorter. They will be stacked up L/S/L/S/L. The short peices should be about 1.5", the long ones about 2". The extra half inch on the long peices will be folded up to create the front of the tailpeice. We will need a mould with a square corner. Two (2) peices of wood glued together will work fine. Now we will: -Saturate the first layer, fold the last .5" over the corner of the mould -2nd layer, no fold. -3rd layer, fold -etc, until the 5th layer. -Let this set. Once it does, take it off the mould. You should have a rectangular base with a 90 corner going up (looks kinda like a standard fender bridge, backwards). -Cut strips of cloth to go on the back of the folded up portion. -Add these 3-4 at a time, until the folded portion is about 3/8" to 1/2" thick. -Drill holes for strings and screws. (UNDER CONSTRUCTION, BBL) Last edited by LewsTherin; 05-08-2006 at 06:05 PM.