WI info

Following is an excerpt from an early (unedited) paper on WI, If you guys like it I will post more. If there is a more appropriate forum let me know, I do not want to upset anybody by clogging up the isles!
I also want to say that in no way am I an expert in this area, I am by no means a master smith, nor do I hold a degree in metallurgy. The following is just what I have learned along the way and what works for me. If you see discrepancies or outright false hoods in the following, by all means post a correction! Thank you.



Ways to identify wrought iron:
1.&nbsp &nbsp &nbsp &nbsp Chemical
2.&nbsp &nbsp &nbsp &nbsp Physical
This paper will not treat on the chemical as I have little experience in those methods and they seem, on the whole, to be impractical for small shop use. It should be mentioned however that chemical identification of wrought iron is carried on in much the same way as for other metals. Various acids and reagents will yield serviceable results and if this interests you I would not discourage further investigation. The main advantage to chemical identification is that it is not destructive in the degree that a physical test is. Therefore it would be better for preservation tasks. Also, it is more accurate than physical testing, as some fine grades of iron may possess slag fibers of such diminutive stature as to be invisible to the naked eye. (Would you believe 250k per square inch?)

Physical tests that indicate wrought iron are simple and quick to perform. With only minimal experience most people can readily identify many grades of wrought. It is of import to note, however, that mere identification will give you no idea of the working properties. The iron must be worked before its quality can be assessed.
The first thing to look for is the grain pattern. This is an indication of slag fibers within the material that have become elongated due to hammering and/or rolling. In many cases the fibers are readily apparent on the surface of the piece, however better grades may not contain visible grain, and some hot rolled steels may exhibit grain,as the result of rolling errors, without corresponding slag inclusions. For this reason the “Nick and fracture” test is generally considered to be the most reliable. To perform this test simply cold chisel partly through the material and bend the piece slowly to fracture the remaining thickness. At this point the grain should be obvious, and if a piece is wrought the grain may appear like hickory.

Having identified a particular piece as wrought iron, the next step is to work it a bit and see if it will be useful for your particular purposes. There are some fundamental qualities to look for.
Wrought iron takes a little more experience to work than steel and someone with no experience would do well to experiment a little with no deadline or expectations before attempting to render and important piece from this demanding material. In general it should be worked hotter than mild steel and it is this area that I have noticed most beginners having trouble. Do not be afraid to really heat a piece, achieving a lemon yellow or greater before beginning to forge it. At low heats WI tends to delaminate, which will be evidenced either directly as a crack on the surface or “shadows” within the iron which indicate differential heating. When drawing down or squaring round stock this problem becomes exacerbated by the fact that grain orientation is unknown. For this reason it is best to take a heat at the end of the rod before beginning work. Estimate the position of the grain and then using a fairly heavy hammer, smartly square the end of the rod through this plane. If you judged correctly the end will square nicely, but if you were off the fibers will shear and the end split, revealing the grain orientation. Simply flux and reweld, hammering through the newly established plane. To illustrate this point, make a “knife hand” (fingers straight and rigid, thumb collinear with digits) and place the pinky side ridge on the table in front of you, fingers pointing away, thumb side ridge pointing straight up. (As if you just Karate chopped the table). Imagine that your fingers are the fibers of the iron. If you were to push straight down on you’re top (pointer) finger. You would compress all of your fingers together. Tilting your hand 45 dgs. And performing the same function would separate and crumple your fingers. If a piece does delaminate it is nothing to worry about, simply flux and work the next heat at a welding temperature and it should close. One thing to be aware of is that some iron will crack laterally, or across the grain, this should only be used for gradual bends or pieces that will not be weekend by this attribute. The only way I have found to avoid lateral cracks is to circumvent them, cutting off the iron that is subject to them and welding a stronger piece in its stead.

Hey Bro, you ARE at the right place to post this. There's some that this will really appeal to, and some who just aren't there (yet). So post away. As long as I'm the moderator, I'll never turn away useful information--even if it's only useful to just one person. We're all here to learn. I, for one, really appreciate your taking the time to post it. Glad to have you hanging out with us too.

When it comes to learning, an old saying my father used to say comes to mind..."Never go into a battle of wits half armed." yuk yuk