8 Aug
2007
8 Aug
'07
8:49 a.m.
On 7 Aug 2007 at 21:39, Chris M wrote:
I bring this up for argument's sake. I had
thought
they were plated with tin. Now...that may not make a
lot of sense (and according to Roy isn't even true),
but is coating something with tin (i.e soldering) and
plating a surface largely different in the durability
of the coating?
Apples and oranges, for the most part. "Tinning" something requires
that the base metal molecularly bond ("wet") with what's being used
for a coating. On the other hand, it's possible, via several
processes, to plate just about any metal onto anything, even
nonconductive plastics.
Hot-dipping/tinning requires that the substrate melt at a higher
temperature than the material used to coat it. Dipping copper into
liquid iron to coat it, for example, would only result in melting the
copper.
As a general rule, plated coatings tend to be thinner (but they don't
have to be) than hot-dipped coatings. The next time you put a new
roof on your house for example, try using electro-galvanized nails
instead of hot-dipped ones. You'll have rusty nails in less than a
year.
There is one other method used for coating, and that's vapor
deposition ("sputtering", PVD, etc.) which tends to produce coatings
much thinner than plated ones.
I don't know if that answers the question.
Cheers,
Chuck