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Old 10-14-2008, 11:31 AM   #31 (permalink)
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Quote:
Originally Posted by gascort View Post
you could add something on the front bumper right in front of the skirt to divert air around it to make sure air doesn't get under there and lift the skirt away from the car.
I'm not relying on aerodynamics to keep the skirt closed - it'll have two springs fore & aft inside the wheel well to keep it in position. The tire will push against these springs when steering. (I think basjoos also has springs inside his.)

Tango - cutting board plastic is a great idea. Thanks. More durable than coroplast, for sure.

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Old 10-14-2008, 11:43 AM   #32 (permalink)
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I think the main reason to go for rollers is the longevity of your hinges. Any
material you choose for rubbing pads will have much greater friction than rollers will.

(geek voice) Plus then, your thkirts will sound like tie-fighterth. That would be cool

Looks good so far. Looking forward to the next stage.
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Old 10-14-2008, 07:37 PM   #33 (permalink)
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So far the frame of your design looks fairly similar to mine except I used a piano hinge that extended along the entire top of the movable portion of the frame and had more clearance over the tires since I needed the room to mount the rollers.
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Old 10-15-2008, 07:59 PM   #34 (permalink)
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I got the frame pretty much finished. I will probably have to weld on a some "tabs" to mount the plastic that the tire will push when turning.



So it's on to making the actual covering that will mount to the frame.

I was planning to use fiberglass because I have more experience with it than trying to form metal. And I'm the coroplast looks a bit too "coroplasty" for my tastes.

The plan was to shape the form of the skirt sculpting expanding spray foam over cardboard as the base, then glass it, then get rid of the foam/cardboard base.

Then I got the idea that if I could build a cardboard base fairly close to the shape I wanted, I'd use drywall mud instead of the foam because (1) it's really easy to sand, and (2) I had lousy luck with the spray foam last time I used it.

So...



There's the mudded skirt, coat 1.

Unfortunately, the water content in the mud just caused the cardboard to warp terribly, so I scrapped that idea.

Plan C?
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Old 10-15-2008, 09:29 PM   #35 (permalink)
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I'd make a template from one pice of cardboard and use pre made body filler that has shreds of fiberglass in it (IE long and strong or kitty hair). then you can build up your fiberglass from there.
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Old 10-15-2008, 09:47 PM   #36 (permalink)
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Probably what I'll do. I went out on a cardboard run tonight - local furniture / appliance store dumpster. (It's supposed to rain later, so if I wanted a good piece I needed to go tonight.)
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Ecodriving test: Manual vs. automatic transmission MPG showdown



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Old 10-15-2008, 09:49 PM   #37 (permalink)
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Couldn't you make a rough shape coroplast base? That would not warp, but then again the mud might not stick well.
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Old 10-15-2008, 10:03 PM   #38 (permalink)
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Plain masking tape is also something you can work with fiberglass just like cardboard.

So get some cardboard and form it to shape and use masking tape to help hold the shape you are interested in. For compound curves use non corrugated cardboard and cut slits in it and tape them smooth. Construction paper also works good for some shapes. The resin will soak through the paper and the masking tape just like the cardboard. So after you get the shape like you want it put a single layer of fiberglass mat over it and resin and let it harden up enough to hold it's shape then put another layer on to make it strong enough to work with.

After that take it off the car and scrape any excess cardboard and tape off the back then put a layer of fiberglass over the back side to seal the cardboard in. If there are some areas that are not right you can sand them down where they need to be and repair any holes you cut in from sanding bad places out. Usually it only comes out a very tiny bit thicker but is just as strong making the parts this way. If you want it to be real thin just use thick paper like poster board paper instead of cardboard.

Also if I remember right, powdered graphite is what you mix in the resin to make the fiberglass black. That way it is black all the way through and scratches won't show up easily in it. It also hides the cardboard so you don't see it through the resin
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Old 10-16-2008, 02:16 AM   #39 (permalink)
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Composite foam is a fantastic medium for building light, strong fibreglass and resin structures. It's a thin layer of foam on a fabric backing. It is used in boat building and it comes with one side cut into small cubes so it can flex. I can't remember the technical name for it but you could call boat builders or fibreglass supply places.

There is also honeycomb which the boat people would have as well.

Enjoying your mod. Becoming inspired.
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Old 10-16-2008, 08:21 AM   #40 (permalink)
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More than one way to skin a cat.

Yuk. That's gross. Who'd wanna skin a cat?
Anyway, yet another way to do it would be to use pink or blue styrofoam from your local home improvement store. Cut, carve, and sand it to shape, then paint it with some latex paint. THEN fiberglass over that. The latex paint keeps the polyester resin from attacking the foam. Then remove the foam mechanically (grinding/sanding/ripping/tearing) or dissolve it with your favorite environmentally-unfriendly chemical.

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