On 1/5/2012 9:30 AM, Ed Huntress wrote:
On Thu, 5 Jan 2012 09:23:48 -0700, "Bob La Londe"
wrote:

wrote in message
...
On 1/1/2012 9:34 AM, Bob La Londe wrote:
snip

perhaps switching to explosive forming would be easier/more fun?

Ooooh! Now that sounds fun.

Let me correct something I said about the tooling. In production, a
big aluminum-forming die for explosive forming typically would be
Kirksite, or ductile iron for a long run, and enough of it to sink a
ship. That's what I've seen in operation.

But they do make dies out of concrete and concrete/fiberglass for very
short runs. I don't know if they're for standoff forming or contact,
but I suspect you need the standoff method to form boats.

That involves an explosive pressure upwards of 40,000 psi. How they
contain that with fiberglass or concrete is beyond what I know.

In any case, it's one heck of a lot of concrete and fiberglass.

there's also hydro-forming, but you may face similar $ related problems.

and it's not as much fun.