[TheForge] Identifying Wrought Iron

[Albin Drzewianowski]

Jim,

See my answers inserted in your text below.

----- Original Message ----- 
From: "Jim Beard" <regionalchaos at gmail.com>
To: "Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Monday, January 29, 2007 11:11 AM
Subject: [TheForge] Identifying Wrought Iron


> Howdy Kind Folks!
>
> Now that the domain is working again...  I had a question about
> identifying wrought iron.  Whats the best way to go about it?  I'm
> assuming you want to be able to see the grain to
> actually tell, so cutting it would likely be the easiest way?  What
> about filing down the surface?  Would that expose grains in wrought if
> they were there?

The most conclusive way for a blacksmith (vs a metalurgist who has a lab 
full of wiz-bang equipment) is probably a spark test.  When held to a 
grinder,  wrought iron gives a very distinct spark pattern: short red sparks 
with no starbursts.  Get a piece of known wrought iron to use as a 
comparison piece.  Collect a number of samples of known steels:  AS36, 
coilspring, old file(high carbon), etc.  Then lightly touch each to a 
grinder and notice the difference in the sparks: color, lenght of sparks, 
amount of forking  and numbers of starbursts.  You want to apply the same 
amount of pressure each time, and do it in dim light if possible.   Now that 
they have battery powered 4 1/2" grinders, you can do this test in the field 
(scrapyard).

Another test which is much more distructive, is to cut a piece half way 
through and then place in vice and bend over and snap the piece,  the 
resulting break will look like you had broken a piece of green wood, it 
would have a fibrous look to it.  Try the same thing with a piece of mild 
steel for comparison.   This test not physically practical in your case with 
1 1/2"  thick chain.

>
> I'm rather new to smithing (being beating hot iron once a week or so
> for the last year at a friends forge) and as such don't have much
> experience identifying metals.  Last week however, I was out at the
> local steel scrap yard (I try to go once a month or so), and found a
> few large chain links.  The links were over a foot or more long, and
> the metal was about 1.5" in diameter.  The metal had been painted over
> (i think) and was covered in a thick layer of dirt.  I couldn't really
> see the surface of the metal.  However, it did seem like it had a
> grain to it.  Almost like the surface was one of a tree branch.  The
> links look like they had been lap welded on one end (as opposed to the
> middle of a side, which is what I have seen examples of..).  Anyway, I
> wondered if these were old Wrought Iron links..

The distinctive bark like look to wrought iron is the result of heavy rust. 
The surface layers of iron rust away, leaving the layers of slag. Usually if 
the item is painted you will not get this affect, unless it was painted have 
rusting.  Becareful removing the paint, if infact it was wrought iron, 
chances are the pain used had a high LEAD content.  So avoid fumes if 
burning off the paint and avoid the dust if grinding/sanding off the paint.

> Also (I'm sure this is a can of worms here) but I've read some
> information about Wrought that says it was not as nice to forge as
> mild steel, yet I hear smiths talk about finding it and liking it too,
> so I'm a bit confused.  Is it easy / hard / fun / boring to forge
> with?

Working with wrought iron is DIFFERENT.  You need to work at a VERY high 
temperature - yellow into white.  Also, you need to take the direction of 
the "grain" into account as you would take the grain of a piece of wood into 
account when making something.



> Thanks!
>
> Jim

Regards,
D-ski
Westminster, MD