I have about 20 years experience with composites in the construction industry so I'll give you my 2 pennies.
DON'T DO IT! It will cost 10 times more money that you think it'll cost if you want to do it right.
Still want to do it?
Okie dokie.. let's cover some basics first so you have a good understanding of the shit involved.
No. 1 Resins
Polyester resin: The same shit you see at home depot , autozone, etc.. It's cheap. It's crap. Breathing this shit in will kill you. The benefit is that it's very easy to use because the mix ratio is not very critical at all. 2% is a good baseline but you can add less or more MEKP(hardener) to vary the cure time. Poly resin will actually cure if left alone by itself for long enough. It may take a year but it will cure without any hardener. You also have to work pretty fast with this stuff as it will get hot and gel real quick rendering it worthless. Oh yeah don't get the MEKP on your skin. It'll cause a chemical burn. Get it in your eyes? You're a blind fucker now. So be careful and protect yourself.
Viny ester resin: Same characteristics as the poly resin as far as mix ratios and the dangers go but superior to the poly resin in almost everyway except cost. It cost just a teeny weeny bit more.
Epoxy: This is the good shit. It costs almost 4 times as much as poly or vinyl but well worth it. There's very little odor so you can actually work with this shit in you kitchen. I don't recommend it but you can. With epoxy the ratio is absolutely critical. If the manufacturer says 3:1 ratio. It better be 3:1 or that shit ain't going to cure no matter how long you stare at it. You almost have to have a weight scale so you can meaure out the resin and hardener by weight which is more accurate than volume. You can get aways with using the metering pumps as captaincapsize suggested. The cool thing is that you can vary the pot life of the resin by using different hardeners so you don't have to hurry to get things layed up. The biggest downside to epoxy is that it is not UV stable so it will breakdown sooner or later with continuous exposure to sun light. You almost have to spray a good uv resistent clear coat to preserve it if it's going to be exposed to sun light.
No. 2 Reinforcements
CSM(fiberglass mat): It can only be used with poly resin or vinyl ester due to the fact that the binders used to hold the strands together will not desolve in epoxy. There are epoxy compatible mats out there that are sewn together rather than using chemical binders. Unless you're building molds, boats, or fabricating car bodies, you will not need to use it.
Woven cloth: This is what you want to use for superior weight savings and strength. For motorcycle parts, I recommend starting with 4oz E-glass or S-glass. S-glass is a bit stronger since the filaments are stiffer. Of course there are different types of E and S glass but we won't go into that. In my experience, I found that 3 oz 4 harness satin weave is the easiest to work with due to the fact that it conforms very well to odd shapes and is thin enough for a superior finish.
Carbon fiber: forget about it. There is none. You can't get it anymore. There's a world wide shortage.
Kevlar: A pain in the fucking ass to cut unless you have kevlar sheers. Try sanding it. You'll soon have a part fuzzy enough that even the star boyz will be envious. Normally you'd want a layer of kevlar as reinforcement at the mounting points. It is very abrasion resistent so it can be good for bodywork as well.
No. 3 Methods of fabricating parts. We'll cover the usual methods
Wet Layup: The usual way bodywork is made. You make a female mold of a part and lay up the material inside and room temp cure it. When done right, it can be quite good as almost all the bodywork manufacturers use this method.
Vaccuum Bagging: Basically wet layup, add release film, breather cloth, bagging film and suck the air out so that the ratio of resin to cloth is ideal. Not the best way but leaps and bounds better than a straight wet layup.
Vacuum Infusion: Lay up the material in the mold completely dry. Vaccuum bag it and infuse the resin into the material. Makes for the best parts this side of NASA and F1.
Prepreg/Autoclave: we won't even touch this as it is cost prohibitive and is usually only used in aerospace and F1.
Still want to try to make your part? Let me know and I'll help you out bro..
Last edited by Chunk; 04-06-2006 at 01:13 PM.