On Sun, 30 Aug 2009 09:48:33 -0400, Joseph Gwinn
wrote:

In article ,
Ned Simmons wrote:

On Fri, 28 Aug 2009 22:08:51 -0500, "Martin H. Eastburn"
wrote:


I bet they had a mixed iron and copper system and did themselves
in without using current breaks - plastic joints.

The absence of ions would rule out galvanic corrosion, no?

I'm not sure that deionized water is in fact free of ions, because the
beads used to fill the water treatment gadget are called ion *exchange*
beads or media. The implication is that they have traded one kind of
ion for another, not that all ions are removed.


The exchanged ions are hydrogen ions and hydroxyl ions.
H + OH - H2O

Does distilled water attack copper et al? I would think not, because
copper stands up to rainwater pretty well.

Rainwater is a long way from distilled water, at least here in the
Northeast. I can't speak to whether distilled water and DI water
affect copper differently. I wouldn't think so, but my experience is
limited to choosing materials compatible with DI water for industrial
processes.

--
Ned Simmons