Body building polycarboate vacuum forming

[mocky]

I used to build formula style bodies at uni and the process goes like this.

1. Get blocks of polystyrene foam, get the denser stuff as it holds a smoother shape when sanded.
2. Make accurate sections at intervals from think plywood or mdf. This gives you a guide to shape the foam. The more accurate and numerous the plywood sections the better, but remember wood takes longer to sand than foam.
2. With a hotwire cutter get the foam blocks into the appropriate size. Then in an alternating fashion glue the foam and wood section using a water based adhesive, such as "liquid nails water base".
3. Begin shaping by sanding the foam areas. Remember to go slow here as it is easier to take material off than put it on. Long light strokes over big areas will get a smoother curve than short strokes. It is also very easy to over sand in the foam areas since the wood is much more difficult to sand.
4. Cover in a thin layer of epoxy or fiberglass-epoxy composite
5. Use a light automotive filler and cover the whole mold and fill in any big holes.
6. Sand the filler layer smooth with 2000grit as your final sandpaper. This is the longest step and the most important, go slow as any mistakes here will great affect the end finish.
7. Paint over it with acrylic paint.
8. Give it another sand with the finest grit you can get your hands on.
9. Apply mold release agent if necessary or gelcoat(a semi-deformable layer that provides a protective layer to the mold to give it re-usability.
10. Ready to make your final product

Very time consuming process, but it's always better to go slow and get it right during the sanding steps than fixing errors after you waste time and money making faulty prototypes. Bog and bondo does dissolve polystyrene, hence a thin layer of epoxy or fiberglass is applied to protect the foam and the mold from impacts. I have heard of people using covering films used in R/C aerofoil construction substituting the epoxy layer.

Due to the complex nature of the Lola bodies you should divide into sections, which can then be glued together later, this way also allows you make mistakes without jeopardizing the entire mold.

[SpeedAssault]

MOCKY, that is really cool experience.

Wow , Thank you so much guy. This is huge help.

so great I can use Polystyrene . I hear ya on using the wood for the sections but I dont know how I would get them just right. I dont have a model to copy from. So I thought I would just start shaping my Styrofoam and use my good eye and measuring
At my last job the model dept used some kind of foam to shape the machine,keyboard,etc. I though I would have to figure out the name and then wonder if I could afford it since I lost my job in 2008.

This makes for a challenging long build. I normally don't worry about cost and do what I can to do it the correct way, but I'm low on cash. all this building money comes from selling things, sucks loosing my job.

Thank you SO MUCH again !