On Wed, 10 Aug 2016 07:32:39 +0700, John B.
wrote:

On Tue, 9 Aug 2016 06:37:42 -0400, "Jim Wilkins"
wrote:

wrote in message
. ..
...
All of the aluminum on my plane is 6061T6 - rivetted.
All flight surfaces and flight structures.

Aluminum boat trailers are routinely welded.

What's the difference?
--jsw

The boat trailer is probably not made from 6061 aluminum :-)
Actually, it is.
See
http://www.easternmetal.com/pdfs/alu...components.pdf