Kirkham Motorsports University Bronze Coupe Fender

[David Kirkham]

Originally Posted by Jamo

Somebody told me somebody wanted a bronze piece to go with a copper one, but I didn't believe him.

So...comparing arruminum, copper and now the time you've had with bronze...what is each material like? Weight? Softness? Durability from skin rashes?

I swear...there are not many folks walking this planet who can repeatedly knock my socks off...amazing stuff.

Doubting Jamo,

Seeing is believing.

Aluminum is very light and quite soft. Aluminum is 1/3 the density of copper or bronze. (Copper is slightly denser than bronze as bronze is copper alloyed with something else, usually tin). In our case, the silicon bronze we are using is about 97% copper and 3% silicon. The silicon helps it to weld and gives it a beautiful golden color.

Copper is softer than bronze, but harder than aluminum. Silicon bronze has a yield strength of around 50,000 psi. The aluminum in the original AC Cobra had a yield of around 10,000 psi. So, you can see the bronze is a beast to form. We had to heat the bronze up to lift it off the die then slap it back down (while hot) to get it to lay down against the die. It was a real job. But, it really made a beautiful part when we were finished. So far, no skin rashes

As for knocking socks off--wait until next week. Sandwich is cooking up something really cool in the mill right now.

David