[TheForge] OK, now I'm mildly perplexed...

[Andy Vida]

Hochewa@aol.com wrote:
> 
> In a message dated 2/14/2004 2:50:26 PM Eastern Standard Time,
> osan@netlabs.net writes:
> 
> > The grain is fine, which I expected, but what I didn't expect was the
> > seemingly high silica content.  I've etched quite a lot of wrought iron
> > and the quality has ranged from basically muck bar to highly refined.
> > In no case did I ever get such a glassy sheen.  I'm assuming this
> > indicates a higher proportion of iron silicate (where's Hochella when
> > you need him?).  Is this in fact the case, or is this odd visual
> > the result of something else?  I etched in HCL to exhaustion.  Could
> > the ferric chloride have caused this?
> >
> 
> To All,
> Beats me!  I would first try fresh acid.  The next thing I would do is cut
> one of the links in half to expose the transverse section and then etch again.
> Let me know.

	OK, I did this.  Fresh acid seems to have revealed the regular
	dull-ish grain.  The end grain etched VERY deeply... and I find
	the grain isn't as fine as I'dve expected.  Voids in the end grain
	far larger than I would have expected from iron employed in a
	high stress component such as a roller chain... unless it wasn't
	high stress :)

	Speaking of manufacture, as I look at it, I'm wondering if this
	could have been built in-house, as it were.  The end of the link
	is not round but appears almost the have been cut in facets with
	a chisel... perhaps it's just the years under water?  You can
	see a scan here at http://netlabs.net/~osan/Photos/WI_Chain_Link.jpg

	The pitch of the chain is about 6".