wrote:
On Tue, 28 Oct 2014 22:00:58 -0500, Califbill
wrote:

True North wrote:
StinkyJim sez

"There's marine grade aluminum and there's tin can aluminum."


You'll be happy to know Stinky, that my boat is marine grade aluminum and
it's at the dealer's right now being repaired under warranty.

What alloy is it? That will tell you if it is marine grade.

I have all sorts of aluminum on my boat and it all seems to be holding
up OK.
I assume the pontoons and rails were marine grade but the square tube
was whatever they use for construction, the expanded metal is from a
welding shop, the jump seat and dog loading platform is from a data
"rack" and I have some gussets cut from road signs.

You need 50xx and 60xx alloys. Very minimal copper in those. 60xx is
tougher, and harder to bend, so most at 50xx of different tempers.