Replacing metal body panels with plastic

[silverhawk_184]

hi,
i have a 97 ranger that has all metal body panels; some of which are in need of a new paint job. This got me thinking, what if i were to replace these heavy all with light, home made body panels. These would be made by vacuforming negatives and then positives, then reinforcing them with a spray type foam insulation. and epoxy on metal brackets (before the foam).

i could even go and make wheel skirts built in.

i mainly drive in town so weight is very important.


Theoretical Procedure:
-Setup
1. make a vaccum platform out of duct board (the stuff department stores use to hang small merchendise on hooks on) and add thin board in the center to cover holes.
2. make vertical rails to align plastic onto the form
3. make a kiln out of scrap bricks i have
4. have a large sheet of stainless steel between heating source and plastic chamber to distribute heat.
5. insert a metal bladed fan between bricks in the back of the kiln for convection current
6. use 2 or more shopvacs in platform
-Procedure
1. Remove body panel from vehicle
2. place body panel on vaccum platform and use sand to make it sturdy and prevent plastic from going under body panel
3. apply some kind of lubercant to body panel. ive read petrolium jelly might work.
4. heat up plastic sheet with a frame until the center droops x inches
5. start up shopvacs
6. take plastic out of kiln
7. quickly align up vertical poles and slide plastic down onto the form
8. wait until plastic cools but is still pliable and remove form body panel
9. sand plastic and fill in any imperfections
10. drill small holes in the peaks of the plastic, for air to come out.
11. repeat steps 2-9 to make positive replica
12. make mounting brackets out of scrap metal to match those on origional and attach with plastic epoxy
13. use spray insulation foam on underside of new body panel for strength (about an inch or two in thickness is all that is needed)
14. test for a fit on vehicle and scrape to remove foam where needed
15. prep for painting as stated in the link below, and proceed to paint.




painting plastic body panels and different types
Background on vacuforming
More info on body painting

[shovel]

A while back, I saw a "custom car" from England that had all home made body panels - it had begun life as a Pajero and the owner scrapped the body (for whatever reason) retaining the floor, seats, dash, and windshield. For the rest he built a wooden frame, stretched pantyhose, and laid glass.

Came out looking pretty silly, chiefly because of the fiberglass "hanging" and forming concave surfaces between the frame pieces - but it sure did look lightweight. Not sure if this helps your idea along at all but there it is

[bikin' Ed]

First, I see no reason for your outlined proceedure not to work. It does seem rather costly and labor intensive. For all of your effort, you will only loose a small percentage of the weight.

My suggestion would be to sculpt a new body design, one that is far more aero than your original, out of foam panels. Cover them with fiberglass. You can use all of the same mounting attachments and hardware glassed into your new body.

You'll achieve about the same weight reduction, save yourself a lot of work, have a more aero vehicle(aero counts, even in town), plus have a one off vehicle, unlike any other.

[silverhawk_184]

thanks, but im afraid, there are very few changes one could make to a pickup to make it more aero and still street legal. besides the obvious angled bedcover, radiator gaurd, sealing the joint between bed and cab, undercarrage cover, and wheel skirts.

i already have a billit grill, which probably helps block air, and looks awsome, but has an annoying resonance at 50-60mph.

i always thought fiberglass was heavy and expensive when compared to plastic.

[nimblemotors]

"Fiberglass" is made from glass fibers and plastic (resin).
You can make it very lightweight by making it very thin, there is fiberglass cloth that is very thin, like rice paper,
Surfacing Veil Mat • Ultrathin: TAP Plastics
But won't have much strength, sandwiched with foam, it might be strong enough to keep its shape, but a rock would probably dig a hole into it.

Originally Posted by silverhawk_184

thanks, but im afraid, there are very few changes one could make to a pickup to make it more aero and still street legal. besides the obvious angled bedcover, radiator gaurd, sealing the joint between bed and cab, undercarrage cover, and wheel skirts.

i already have a billit grill, which probably helps block air, and looks awsome, but has an annoying resonance at 50-60mph.

i always thought fiberglass was heavy and expensive when compared to plastic.

[sid]

Also, don't let your insurance company find out about it. Anything that potentially changes the structural integrity and passenger safety could get your insurance canceled.

[redpoint5]

Effort and cost will not be worth the fuel savings, but it would be neat to see regardless. If you really want to save fuel, see about driving something more efficient in town.

[EdKiefer]

I don't mean to sound negative, but if your going to replace just the skins of doors, fenders, quarter panels and hood I think it will save nothing in the end and even be heavier .

My experience with working with fiberglass is if you want it looking good it needs many layers and filler and this adds weight. Also the skins/panels of body are not heavy by themselves . If you plain to make a full frame of glass/plastic like a Vette is thats another story but would be hard for avg person to reproduce that kind of effect IMO .

[Varn]

There is a steep learning curve to make composite parts.

If you want to try, start small, make something non structural.

I used stretched cloth to make a grill cover on my minivan and it came out good. It was not my first project