fiberglass or steel?

[kennyd]

we like to use expandable foam from ,aircraft spruce co. its called x-30 2 part and if goes a long way . remember it expands alot !!

[astroracer]

If you build a buck out of MDF you can stretch T-shirt material over it to soften the lines. Once you get the look you want apply fiberglass resin to the material to stiffen it up and then glass over that. Works very well for making soft, smooth curves without a lot of effort.
Mark