Plane irons- wrought iron?

[greg Forster]

I have quite a few old/ used up plane irons, with "laid-on" steel. Is the iron portion of the blade true wrought iron? I have both English and American irons; my interest is that I'm always looking for a source of high quality wrought iron to re-forge.

[george wilson]

Depends upon how old the iron is. I even have had a recently made Marples jack plane,back in the 70's, that had a laid on blade.

The farther back plane irons go,the more angle there is on the beveled corners at top of the iron. In the 18th.C.,the irons had round tops. Then,they chopped off the corners at 45º. As time went on,the angles got longer and longer down the sides of the blade,until today we have the long,tapered angles.

If the blade has 45º angles on its top corners,it is probably wrought iron.If you polished the back of the iron smooth,by filing,then polishing with abrasives,it would show little streaks of silicon inclusions. A drop of nitric acid turns wrought iron GRAY,not black. You probably don't have nitric acid(it's on the list of things explosives can be made from). Polishing a part of the blade,and just soaking in vinegar might be enough to bring out a woody looking grain structure. You might have to soak it for quite a while as vinegar is weak. Lemon juice would also work,as lemon juice is used by knife makers who make damascus steel knives to bring out the pattern.

I have also used Clorox to bring out damascus pattern pretty quickly.

[David Keller NC]

Greg - The catch is that an uncut iron in good shape is worth considerably more than the wrought iron that's in it. I was considering the same thing, but decided it was better to buy wrought iron that salvage it from plane irons.

[george wilson]

You can get wrought iron from old decorative iron fences. Look for a wood like texture in the rust patterns. Old bridges used wrought iron,too. Light house fittings and old anchors were wrought iron.

It was used because its layers of silicon inclusions prevented it from rusting all the way through. Most of the wrought iron we got for Wmsbg. came from salvaged bridge metal.

About 30 years ago,a bunch of us got together and bought out the remaining round bar stock from the New England Lighthouse Fitting Co.(think that's the whole name.)

[David Weaver]

I agree with David. If you can figure that they are wrought iron, I would sell them in the S&S - they are usually good fine-grained irons, even if a little soft from time to time.

[george wilson]

I have read that mild steel came into the prominent use because it electric welds better than wrought iron. So,when electric welding was invented,wrought iron was on the way out,except for the types of uses I mentioned above. Wrought iron FORGE welds better than mild steel,so blacksmiths still like to get it if they can.

[David Weaver]

A google search yields remarkably little about wrought iron other than that there is an english company looking to get wrought iron and offering it for sale.

Japanese tools will come with it new (recycled, though) if you are willing to pay for it, though you don't have to pay too much for it. I have seen comments from various vendors that it is from anchor chain, bridges, and structural sources.

I have also seen unscrupulous comments from some japanese tool vendors that make it out like it's a lot rarer than it is.

Though, I suppose that's common in marketing. I also remember a guitar maker talking up ash as if it's something rare and exotic.

Searching for wrought is muddied by the fact that there are scads of products marketed as wrought that clog up the search engines - when they are nothing more than mild steel bent into a pattern and painted black.

[Mike Henderson]

Real wrought iron was made by a process that didn't completely melt the iron. The iron was a mass called a bloom, which consisted of iron and slag. The bloom was hammered to attempt to drive out the slag but it never produced pure iron - the iron always contained some of the slag, usually in streaks as George pointed out. The big advantage of real wrought iron is that the slag interrupted rust and withstood adverse conditions better than pure iron. Note that real wrought iron usually does not contain much carbon, certainly not enough to harden it through heat treating.

The problem was that making real wrought iron was VERY labor intensive and thus more expensive than the processes that replaced it (Bessemer and open hearth). The Bessemer and open hearth produced what was called "mild steel', iron with a low carbon content and essentially no slag (but maybe some other impurities). After Bessemer and open hearth mild steel replaced wrought iron there were still calls for real wrought iron. Some well known steel maker patented a process of making "wrought iron" from mild steel, by pouring slag back into the mild steel and stirring it some way to entrain the slag in the mild steel. I only read about the patent so I don't remember the process real well. Even that was more expensive than mild steel and it never went anywhere.

Mike

[george wilson]

I believe you refer to "Byer's iron" (sp?) It had technically the same chemistry as wrought iron,but not really the same structure since it was not WROUGHT by hammering the slag out of the bloom. They used to have some of this iron in Williamsburg in the 70's.

There is a new product out,called something like "Pure Iron." The maintenance blacksmith got some to try out,and we got a sample from them when I was toolmaker. I may not be calling it by the correct name as I didn't use it,or buy it.

I have some 1/2" square wrought iron that a guy bought to make a railing around his porch for. New,it has a lavender,smooth coating on it rather than the brown rust you always see. This is Ferric oxide,rather than ferrous oxide,which mild steel,or any carbon steel produces.

This stuff might be o.k. for outdoor use,but it is miserable stuff. I actually sawed part way through a sample,and BY HAND with a pair of pliers,was able to peel back the metal like a banana peel. It would separate in layers due to the silica layers in it.

I have also played around with old shotgun barrels. It is entirely better,and tough as blazes,but still wrought iron,better refined.

[Mike Henderson]

I found the reference on that wrought iron process. It's the Aston process. There's a bit in Wikipedia, here (http://en.wikipedia.org/wiki/Wrought_iron#The_Aston_process), on it.

Mike