On Mon, 10 Dec 2007 20:48:04 GMT, Brian Whatcott
wrote:

On Mon, 10 Dec 2007 00:14:16 -0600, cavelamb himself
wrote:


THere have been at least a million aluminum airplanes produced. All
were riveted. Wonder why?


Lowest bidder?


not hardly.

Best fastener for the material.

Rivets were the best fastener for ships until they started welding
plates (then a few Liberty ships sank before the subs got 'em.)

Brian W

Most of the high strength aluminum alloys are not weldable.

See Materials specification for 2024 - one of the more commonly used
aircraft alloys:

Welding

Welding may be done by use of resistance welding or inert gas
consumable electrode arc method. However it must be noted that, in
general, welding by any means is NOT recommended for this alloy
because of the degradation of corrosion resistance that occurs as a
result of weld heat. A repeat heat treatment should be done if welded.

Bruce-in-Bangkok
(Note:remove underscores
from address for reply)