Working with carbon fiber.
06-07-2002, 05:40 AM
#1
Burning Brakes
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Working with carbon fiber.
Would it be posible to make a carbon fiber peice that replaces the Heater cover between the battery and the fuse box up by the windshield? It is broken and cracked on every 944 I've ever seen. I have never worked with carbon fiber kits and I'm just wondering how hard it would be to mold this... I could just buy a new one but I want something more durable.
Thanks,
Thanks,
06-08-2002, 02:56 AM
#3
Race Director
Sure, piece of cake! Not sure if it would be worth the effort for you though.
First you need to make a negative mold. Perhaps out of fiberglass. Spray mold-release compound all over your part. Lay down gel-coat first, then lay down 2 layers of fiberglass mat and resin. Wait until it's tacky to the touch. Mix some 2-part foam (available at surfboard-making outfits). Lay down a 1/4"-1/2" layer of foam on top of fiberglass. When that's dry, trim around edges to expose original fiberglass layer. Then lay down 2 more layers of fiberglass (meeting up with original layer around the edges) to completely enclose the foam. When everything's completely dry, pop mold off part and you're ready.
Inspect mold and make any fixes and repairs. Spray mold-release compound on mold. Lay down a thin layer of gel-coat. Then follow with a layer of woven carbon-fibre. Add thin layer of resin. Next is one layer of unidirectional carbon-fibre oriented at 30-45 degrees to wowen layer. Another thin layer of resin. Lay down on more layer of unidirectional carbon-fibre at a mirror-image angle to the first (-30-45 degrees compared to woven layer). Lay down heavy layer of resin. Wait til the whole ensemble is dry. Pop off from mold, trim/finish edges and you're set!
First you need to make a negative mold. Perhaps out of fiberglass. Spray mold-release compound all over your part. Lay down gel-coat first, then lay down 2 layers of fiberglass mat and resin. Wait until it's tacky to the touch. Mix some 2-part foam (available at surfboard-making outfits). Lay down a 1/4"-1/2" layer of foam on top of fiberglass. When that's dry, trim around edges to expose original fiberglass layer. Then lay down 2 more layers of fiberglass (meeting up with original layer around the edges) to completely enclose the foam. When everything's completely dry, pop mold off part and you're ready.
Inspect mold and make any fixes and repairs. Spray mold-release compound on mold. Lay down a thin layer of gel-coat. Then follow with a layer of woven carbon-fibre. Add thin layer of resin. Next is one layer of unidirectional carbon-fibre oriented at 30-45 degrees to wowen layer. Another thin layer of resin. Lay down on more layer of unidirectional carbon-fibre at a mirror-image angle to the first (-30-45 degrees compared to woven layer). Lay down heavy layer of resin. Wait til the whole ensemble is dry. Pop off from mold, trim/finish edges and you're set!
06-08-2002, 03:48 AM
#6
Race Director
I guess for that 'trick' look. You can simulate it with fiberglass by adding enough black coloring to the resin so that's it's semi-transparent. Then light will still bounce off the fiberglass layers to give it that woven carbon-fibre sheen (even though unidirectional is much stronger).
06-08-2002, 07:08 AM
#7
When I was in the Navy, i attended the Synthetic Strucures Repair School, or somesuch military name.
We worked on quite a few cool types of resin/fiber composites, including some really killer low temp carbon fiber for repairing FA-18's.
It is amazing how easy it is to work in composite. Until just recently, I flew ultra light remote control electric aircraft. Some of my lightest composite planes were under 4 oz., which in nothing considering that many full function aircraft are under 2oz. But the ability to make my own parts and wings was extremely useful.
You can make molds from anything, wood, clay, metal, sawdust, whatever. Or you can use the part you want copied. Just coat it well in release compound like Danno said. Then gel coat, then start layering your fiber, whether carbon or glass. Use at least 3 layers of fiber, more is good, but dont get crazy with the 2" thick stuff, the epoxy will not set well. It all really depends on the type of duty your new part will see.
Work in low temps if possible, to allow you the longest set times. Fast-setting epoxy sucks. The longer your set time, the stronger your final set strenght will be. this makes for durable parts, with fewer "weak spots" Dont move the part during the set time. It will cause microscopic fractures in the epoxy.
For cheap and easy jobs, Lemon Pledge makes a fairly decent release agent, and 30 minute epoxy can be thinned with alcohol to use on glass. Not too thin, just enough to get it to brush on easier. Experiment, its easy to find stuff you wouldnt mind having another of, or lighter.
For some really cool electric jet, under 10 oz!, I have used balsadust (think sawdust sanded off of a big chunk of balsa.), sprayed with 30 minute epoxy out of a pump spray bottle to make the entire intake ducting. It was sprayed onto a paper towel tube covered in Saran Wrap that I added some Play-Doh I heisted from my kids to make the intake the right shape to flow the air faster. I used the Hoover to draw a vacuum on teh entire thing, after covering with saran wrap again. It was really light, under 5 grams for the entire thing. makes me think I might try molding my quarter-panels. LOL!!! With carbon, I could get them under 5lbs I bet, not really strong, but super light. Vacuum tables are easy to make, and you can make professional looking parts with ease with a little vacuum.
Want a new splitter? It might be easier than you think, and probably 50% maybe 75% of the cost, once you figure in a little extra for first time practice materials and "oops" stuff. But after you learned the basics, anything else is cheaper cause you wont need to do it twice. It would be fairly easy to make a reverse mold with a 2x8 and a router bit. Or a positive mold from clay or wood, just sand to shape. Or make some of those killer brake ducts to relpace the fogs, like that killer blue car. Only scooped like an actual intake, to accelerate the airflow. Hmmm....
I am babbling.
Oh yeah, wear gloves. Epoxy causes a reaction based on exposeure. Everyone becomes allergic, some faster than others. DOnt get it on you. And wear a mask when you sand, and eyewear too. It can attack your nasal and lung tissues.
Fun stuff!
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
We worked on quite a few cool types of resin/fiber composites, including some really killer low temp carbon fiber for repairing FA-18's.
It is amazing how easy it is to work in composite. Until just recently, I flew ultra light remote control electric aircraft. Some of my lightest composite planes were under 4 oz., which in nothing considering that many full function aircraft are under 2oz. But the ability to make my own parts and wings was extremely useful.
You can make molds from anything, wood, clay, metal, sawdust, whatever. Or you can use the part you want copied. Just coat it well in release compound like Danno said. Then gel coat, then start layering your fiber, whether carbon or glass. Use at least 3 layers of fiber, more is good, but dont get crazy with the 2" thick stuff, the epoxy will not set well. It all really depends on the type of duty your new part will see.
Work in low temps if possible, to allow you the longest set times. Fast-setting epoxy sucks. The longer your set time, the stronger your final set strenght will be. this makes for durable parts, with fewer "weak spots" Dont move the part during the set time. It will cause microscopic fractures in the epoxy.
For cheap and easy jobs, Lemon Pledge makes a fairly decent release agent, and 30 minute epoxy can be thinned with alcohol to use on glass. Not too thin, just enough to get it to brush on easier. Experiment, its easy to find stuff you wouldnt mind having another of, or lighter.
For some really cool electric jet, under 10 oz!, I have used balsadust (think sawdust sanded off of a big chunk of balsa.), sprayed with 30 minute epoxy out of a pump spray bottle to make the entire intake ducting. It was sprayed onto a paper towel tube covered in Saran Wrap that I added some Play-Doh I heisted from my kids to make the intake the right shape to flow the air faster. I used the Hoover to draw a vacuum on teh entire thing, after covering with saran wrap again. It was really light, under 5 grams for the entire thing. makes me think I might try molding my quarter-panels. LOL!!! With carbon, I could get them under 5lbs I bet, not really strong, but super light. Vacuum tables are easy to make, and you can make professional looking parts with ease with a little vacuum.
Want a new splitter? It might be easier than you think, and probably 50% maybe 75% of the cost, once you figure in a little extra for first time practice materials and "oops" stuff. But after you learned the basics, anything else is cheaper cause you wont need to do it twice. It would be fairly easy to make a reverse mold with a 2x8 and a router bit. Or a positive mold from clay or wood, just sand to shape. Or make some of those killer brake ducts to relpace the fogs, like that killer blue car. Only scooped like an actual intake, to accelerate the airflow. Hmmm....
I am babbling.
Oh yeah, wear gloves. Epoxy causes a reaction based on exposeure. Everyone becomes allergic, some faster than others. DOnt get it on you. And wear a mask when you sand, and eyewear too. It can attack your nasal and lung tissues.
Fun stuff!
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
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06-08-2002, 07:14 AM
#8
[quote]Originally posted by Danno:
<strong>I guess for that 'trick' look. You can simulate it with fiberglass by adding enough black coloring to the resin so that's it's semi-transparent. Then light will still bounce off the fiberglass layers to give it that woven carbon-fibre sheen (even though unidirectional is much stronger).</strong><hr></blockquote>
I have used regular food coloring to make some really cool CF-look sailplane wings in rainbow colors. I wonder if it would be practical to add other types of dyes/paints to the epoxy. It would be possible to make some pretty cool faux-CF stuff, but in candy colors to match paint. I think it would be cool as crap to have a Guards car with the interior dash parts that everyone puts wood or CF trim on already, but have the trim in a deep blood red CF.
Or mix a bottle of Testors aluminum/silver model paint in the epoxy, make a killer silver CF. My only concern is the weakening of the epoxy bonds. But interior trim isnt a particularly high stress component.
Bah, babbling again, off to bed.
<img src="graemlins/sleep.gif" border="0" alt="[sleep]" />
<strong>I guess for that 'trick' look. You can simulate it with fiberglass by adding enough black coloring to the resin so that's it's semi-transparent. Then light will still bounce off the fiberglass layers to give it that woven carbon-fibre sheen (even though unidirectional is much stronger).</strong><hr></blockquote>
I have used regular food coloring to make some really cool CF-look sailplane wings in rainbow colors. I wonder if it would be practical to add other types of dyes/paints to the epoxy. It would be possible to make some pretty cool faux-CF stuff, but in candy colors to match paint. I think it would be cool as crap to have a Guards car with the interior dash parts that everyone puts wood or CF trim on already, but have the trim in a deep blood red CF.
Or mix a bottle of Testors aluminum/silver model paint in the epoxy, make a killer silver CF. My only concern is the weakening of the epoxy bonds. But interior trim isnt a particularly high stress component.
Bah, babbling again, off to bed.
<img src="graemlins/sleep.gif" border="0" alt="[sleep]" />
06-08-2002, 07:44 PM
#9
Three Wheelin'
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You can just use one layer of carbon on the exposed sides and use a layer or two of roving/mat/E-glass underneath to build up some thickness and make it cheaper. Graphite/Carbon is about 5 time more expensive than glass.
Or maybe a carbon/aramid weave to create a nice eyecatching color contrast and add a bit of durability.
Or maybe a carbon/aramid weave to create a nice eyecatching color contrast and add a bit of durability.
06-08-2002, 11:42 PM
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this is some pretty cool stuff. i never knew it was that easy to produce carbon fiber and fiberglass parts. where do you get the materials for these kinds of projects.
06-09-2002, 12:41 AM
#13
Three Wheelin'
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<a href="http://www.aircraft-spruce.com/" target="_blank">Aircraft Spruce</a> has a huge catalog with all kinds of good stuff for DIY fabricators. Their target is builders of experimental aircraft, but the same materials are directly applicable to auto fab work.
Look in your phone book for local fiberglass shops. If you live in a coastal area or near a lake, there should be many local sources since they use a lot of glass for boat repairs/construction. On the west coast, we have
<a href="http://www.tapplastics.com/stores/index.html" target="_blank">Tap Plastics</a>.
Look in your phone book for local fiberglass shops. If you live in a coastal area or near a lake, there should be many local sources since they use a lot of glass for boat repairs/construction. On the west coast, we have
<a href="http://www.tapplastics.com/stores/index.html" target="_blank">Tap Plastics</a>.
06-09-2002, 01:02 AM
#14
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[quote]Originally posted by sean bartsch:
<strong>this is some pretty cool stuff. i never knew it was that easy to produce carbon fiber and fiberglass parts. where do you get the materials for these kinds of projects.</strong><hr></blockquote>
For non-load bearing parts, the rigidity and durability are not as important. If you want to fabricate load bearing parts, you should have a good understanding of the loads that the parts will experience and engineer your parts accordingly.
<strong>this is some pretty cool stuff. i never knew it was that easy to produce carbon fiber and fiberglass parts. where do you get the materials for these kinds of projects.</strong><hr></blockquote>
For non-load bearing parts, the rigidity and durability are not as important. If you want to fabricate load bearing parts, you should have a good understanding of the loads that the parts will experience and engineer your parts accordingly.
06-09-2002, 07:33 AM
#15
Yeah, you definately dont want to be fabbing A-arms from carbon honeycomb your first time out. Although it is possible. Just think about the B-2 bomber. With a full load of munitions, fuel and crew, the carbon wing doesnt droop one inch. And that plane has no internal spar, the wing is hollow! That is some serious bad-**** composite.
But homemade interior trim, or a simple splitter, would be a good project. Just dont be too sad if your first effort isnt what you hoped. It isnt hard, but experience shows.
I have been thinking more about the splitter, and how to do it cheap. At this point, I figure about $60 worth of materials could make a pretty nice gel-coated race-type splitter. Depends on what type of mold you made. And your level of handcrafting skill. If you made the original mold from foam covered in a light layer of glass, you could probably do it for under $50.
I would buy about $20 worth of styrofoam blocks from a hobby/craft shop, pieces that were 8-10" wide, 1-2' long, and at least 3" thick. Old ladies use this stuff for everything. Hot glue 4 or 5 together to make a section long enough to fit the front end with some overlap. Add [ieces to make the bends at the sides of the car. Then just cut/sand to shape, making sure you frequently check the fit to the front end of the car. It would probably be wise to make a paper template with your batwing, or off of the front spoiler. It shouldnt take long since its styrofoam, and if you screw up, its cheap. Then lightly glass the finished piece. Be careful to use a low-heat epoxy/resin. No fast set stuff.
Then just apply release, build up a nice thick layer, and let it set up. Sand it smooth and do any finish shaping, gel-coat, and paint. Then drill your mounting holes (go back and "paint" in a thin layer of epoxy into the drilled holes), and shazam. (well, it might be smarter to paint last.) You could also concievably just glass over the foam mold, using the foam as a structural component. You would need to make the mold thinner and slightly smaller to compensate. I also like Danno's surfing foam, but its kind of pricy compared to the styro, and once glassed, both will be plenty strong. I have even tried that "insulating foam in a can" stuff, with mixed results. It is light, but hard to apply well. You can also laminate in all of your mounting brackets if you plan ahead.
Like Chris pointed out, I am interested in finding out what kind of structural integrity a splitter needs. How much stress will it see at 150MPH? 200lbs? More or less? I know I can build a piece strong enough to stand on/jump on without breaking, but mounting? Would the splitter need to be popriveted? or would L brackets work? It could be applied flush to the existing spolier, but it would require more work and prep/finish time.
I would try one, but since I am currently prepping for a move, I cant really start busting the tools and stuff out of the boxes, my wife would harm me.
You could also make one pretty easy by taking one off of a buddy's car and copying it.
I am actually thinking for myself, maybe a mold made in plaster or clay, one like this...yeah right, in my creams. Hehe, I am gonna leave that typo, lol.
This is some sexy glass work.
This is toooo! Having seen a photo of a 944/951 with the rear quarter panel inserts from a Boxter, I think that this would be Uber-Svelte on a 951.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
But homemade interior trim, or a simple splitter, would be a good project. Just dont be too sad if your first effort isnt what you hoped. It isnt hard, but experience shows.
I have been thinking more about the splitter, and how to do it cheap. At this point, I figure about $60 worth of materials could make a pretty nice gel-coated race-type splitter. Depends on what type of mold you made. And your level of handcrafting skill. If you made the original mold from foam covered in a light layer of glass, you could probably do it for under $50.
I would buy about $20 worth of styrofoam blocks from a hobby/craft shop, pieces that were 8-10" wide, 1-2' long, and at least 3" thick. Old ladies use this stuff for everything. Hot glue 4 or 5 together to make a section long enough to fit the front end with some overlap. Add [ieces to make the bends at the sides of the car. Then just cut/sand to shape, making sure you frequently check the fit to the front end of the car. It would probably be wise to make a paper template with your batwing, or off of the front spoiler. It shouldnt take long since its styrofoam, and if you screw up, its cheap. Then lightly glass the finished piece. Be careful to use a low-heat epoxy/resin. No fast set stuff.
Then just apply release, build up a nice thick layer, and let it set up. Sand it smooth and do any finish shaping, gel-coat, and paint. Then drill your mounting holes (go back and "paint" in a thin layer of epoxy into the drilled holes), and shazam. (well, it might be smarter to paint last.) You could also concievably just glass over the foam mold, using the foam as a structural component. You would need to make the mold thinner and slightly smaller to compensate. I also like Danno's surfing foam, but its kind of pricy compared to the styro, and once glassed, both will be plenty strong. I have even tried that "insulating foam in a can" stuff, with mixed results. It is light, but hard to apply well. You can also laminate in all of your mounting brackets if you plan ahead.
Like Chris pointed out, I am interested in finding out what kind of structural integrity a splitter needs. How much stress will it see at 150MPH? 200lbs? More or less? I know I can build a piece strong enough to stand on/jump on without breaking, but mounting? Would the splitter need to be popriveted? or would L brackets work? It could be applied flush to the existing spolier, but it would require more work and prep/finish time.
I would try one, but since I am currently prepping for a move, I cant really start busting the tools and stuff out of the boxes, my wife would harm me.
You could also make one pretty easy by taking one off of a buddy's car and copying it. I am actually thinking for myself, maybe a mold made in plaster or clay, one like this...yeah right, in my creams. Hehe, I am gonna leave that typo, lol.
This is some sexy glass work.This is toooo! Having seen a photo of a 944/951 with the rear quarter panel inserts from a Boxter, I think that this would be Uber-Svelte on a 951.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />