I have a glass fibre car with a rotten mild steel space frame chassis. Is it feasible to replace (partially replace) with your carbon fibre tubes and sections? I mean would they be strong enough. The main rust is in the main backbone chassis and the sections that come out along the sills. If i have a 1inch mild steel tube section what would i replace that with for same strength?

I would replace complete section for instance the whole backbone not just patch up the rusty bit.

Graham

Thank you for your answers!  I don't want to hijack a thread, so feel free to keep me in line.

"In most cases its easy to overengineer such things with some simple knowledge and experience, and with lightweight composites that is usually fine and still achieves what the guy wants. "  Where might I go for some simple knowledge?  I'm willing to over-engineer, and willing to have extra weight as a trade-off.  I've built machines and equipment using principles of over-engineering based on charts of structural steel strength.  And not to worry, if I am not sure of safety and strength, I'm not going to build it. A cool looking car is not worth a horrible accident.

Thanks again!