On Tue, 01 Mar 2005 11:09:02 +0000, doozer
wrote:

I am curious. What could you possible want to install for 150 to 200 years?

I would imagine given that amount of time dissimilar metals will corrode
significantly. Probably to the point of failure. Is it vital that they
are dissimilar metals and that they are irreplaceable for 150 years?

Its not actually me that is using it but a fellow building
conservator, working in the attic of an important building - the
ceiling is trying to fall down and we are trying to stop it doing
that. Standard practice is to do everything in stainless (threaded
rod, screws, washers, wire etc) so I was surprised when they started
using aluminium wire

Aluminium is an interesting case because it is actually a highly
reactive metal* but in the presence of oxygen it forms a tough oxide
(rust) coating that stops further reaction. Perhaps as long as you don't
continually damage that coating (e.g. they joint is completely
immobile) it might last quite well.

It should be immobile so lets hope so

Anna
~~ Anna Kettle, Suffolk, England
|""""| ~ Lime plaster repairs
/ ^^ \ // Freehand modelling in lime: overmantels, pargeting etc
|____| www.kettlenet.co.uk 01359 230642