I find this very interesting.

When using flux, the flux will disolve impurities on the surface and carry them out during the welding process. With the kerosene process, I trust that the billet needs to be perfectly clean as the kerosene only protects the billet and provides no means of disolving surface impurities on the billet. Is this correct?

Thanks

Brian

Brian,

I cut, grind clean with used 50 grit, and stack, whether I'm welding with flux or kerosene.

I also grind mill scale off the 1084 before the first weld, so I can't give first hand info on this, but Ron N. and others don't grind off the mill scale from the 1084 before the first weld, and report the same absolutely clean welds. Go figure.

An interesting question is this: if the kerosene welding system works, and it does, then is the theory of flux welding that we all repeat correct, or is something else going on in flux welding?

One thing about flux is that, while it may help squirt out impurities, the flux itself is a gross impurity that has to be gotten out.

John

Thanks for the reply John. This concept is becomming even more interesting. As you stated, this concept does indeed make one question what exactly is going on when flux welding -- or any forge welding for that matter.

It just goes to show that even after centuries of a tried and proven method, there is always room to learn more.

Anyone know who came up with this idea and if it was a accidental finding or an experiment?

Thanks

Brian

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Hmmm...Interesting. I've used kerosene and WD40 in closed dry welds, as in a containment box for mosaic type stuff, but never in an "open" welding situation(a regular billett)I'm having some trouble understanding the chemistry and physics behind the principles that allow a weld with such a procedure. How do the metals in use weld when covered with carbon???

JD,

The kerosene/Wd-40 don't burn inside the can, they burn when they volitize, expand and come out of the can?

Mike

This is one I've also heard about but never tried. That said, I've got 5 gallons of diesel in a can that I could use to give it a shot...I too am curious about why it works though...I hate it when I can't explain why something happens in my shop.

-d

As most of us probably tend to use steel that has been ground clean, it follows logically that flux is used primarily to get rid of nasty crusties that are formed during the heating process. It sounds like the kerosene "flux" is somehow preventing those evil oxygen nourished crusties from forming in the first place much like welding the seams shut or using a can does. The big question may be how is it that the soot or whatever byproduct of burning the kerosene seals off the steal from the atmosphere of the forge and yet manages to be "clean" enough not to introduce bad impurities, etc into the billet.

I have been involved in several conversations about kerosene welding, as well as having attended some damascus demos by smiths who use kerosene as a "flux". Somewhere during these discussions, I heard mention of a theory for why kerosene works for forge welding. I don't recall for certain who offered this hypothesis, but I will try to make some contacts to identify the individual and get him to post to this thread. Below is what I BELIEVE that I heard as an explanation of how kerosene welding works.

When the kerosene soaked billet is placed into the fire, the lighter volatile elements quickly burn off, leaving behind carbon. The carbon with its higher ignition point remains between the layers of steel until the steel heats to the temperature where combustion of the carbon can begin. The proper reducing forge fire, being oxygen deficient, forces the carbon to seek oxygen from a source other than the atmosphere of the fire to sustain combustion. The carbon finds the oxygen it requires in the forge scale (i.e., iron oxide; FeO) on the steel. By pulling the oxygen from the iron oxide, the carbon effectively changes the iron oxide back into iron (Fe).

I also heard a supporting statement made for this process saying that Japanese swords have been welded for centuries using only charcoal dust between the layers of steel.

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When the kerosene soaked billet is placed into the fire, the lighter volatile elements quickly burn off, leaving behind carbon. The carbon with its higher ignition point remains between the layers of steel until the steel heats to the temperature where combustion of the carbon can begin. The proper reducing forge fire, being oxygen deficient, forces the carbon to seek oxygen from a source other than the atmosphere of the fire to sustain combustion. The carbon finds the oxygen it requires in the forge scale (i.e., iron oxide; FeO) on the steel. By pulling the oxygen from the iron oxide, the carbon effectively changes the iron oxide back into iron (Fe).

Ok Mr. Culver, now you've got me curious...If I understand the mechanism described correctly one should be able to test this theory by taking a piece of steel with scale still attached and sealing it into a vessel packed with charcoal dust. Heat it, and then observe the steel's condition. If having the FeO (is scale Fe02 or Fe03? I always forget...) in contact with a pure carbon medium at heat will cause the scale to lose oxygen to the carbon this should in effect turn the scale on the test piece back into straight iron too correct?

This also raises a question in my mind about how iron needs to be prepared if one is making shear steel...I always assumed it would need to be ground clean for the carbon diffusion into the piece to take place, but maybe this isn't so?

Thanks for making me think a little more,

-d

Hi Robert,

I don't feel that I am knowledgeable enough to answer your questions about sealing a piece of steel in a vessel with charcoal and how to prep shear steel.

As to the correct chemical formula for forge scale, I did some brief research and found several possible variations to the formula for iron oxide. The difference in the formulas depend on how the iron oxide was created. Below are some formula examples and explanations that I found. I really don't know what formula is correct for forge scale.

"Red rust is Fe2O3 (Iron (III) oxide)"

"Rust is a combination of Ferric (Fe3O2) and Ferrous (FeO) Oxide depending on the conditions under which it formed."

I am going to try to get someone who is much more familiar with kerosene damascus welding to add to this post. Maybe we can get a true expert to answer our questions about this process.

Another though occurred to me while mulling this over. If it is indeed a coating of carbon that allows for this to happen, what would happen if you were to coat your pieces with lampblack (eg. from an acetylene torch) before stacking? It's not at all practical, but it would be an interesting test of the hypothesis. I don't have an acetylene rig though, so I can't try it myself.

-d

Not a chemist but... from an article by a chemist at American Longrifles forum... FeO, Fe2O3, & Fe3O4. Ferrous Oxide, Ferric Oxide, Ferrosoferric Oxide. The type formed is driven by the oxidizing conditions... amounts of available O2.

From DogPile "iron scale"... Iron scale, the thin film which on the surface of wrought

the magnetic oxide of iron, Fe3O4

Mike

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This also raises a question in my mind about how iron needs to be prepared if one is making shear steel...I always assumed it would need to be ground clean for the carbon diffusion into the piece to take place, but maybe this isn't so?

Thanks for making me think a little more,

-d

I watched Ric Furrer doing a shear steel demo a few years ago at Larry Harleys hammerin.

he took wagon tire, drew it out to 10 - .5x.125 strips about 6 inches long, threw them straight into a can with Case-Nit and fired it for a couple hours. grabbed the pieces out of the box, welded a handle on and forged them into a billet.

never cleaned or ground anything beyond a stiff brushing

|quoted:

I watched Ric Furrer doing a shear steel demo a few years ago at Larry Harleys hammerin.

he took wagon tire, drew it out to 10 - .5x.125 strips about 6 inches long, threw them straight into a can with Case-Nit and fired it for a couple hours. grabbed the pieces out of the box, welded a handle on and forged them into a billet.

never cleaned or ground anything beyond a stiff brushing

So they went into the can with forge scale on them, got case hardened (near surface carbon skin and/or carbonized the scale), and forge welded? Was the welding one fell swoop... out of the forge then done... or multiple reheats?

Mike

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So they went into the can with forge scale on them, got case hardened (near surface carbon skin and/or carbonized the scale), and forge welded? Was the welding one fell swoop... out of the forge then done... or multiple reheats?

Mike

steps:

after allowing the can to cool to a handleable temp

cut the end off the can

dump contents into slack tub

fish out cased bars

stacked the bars.

welded a handle

fluxed

welded

no processing was done to the bars after casing,

he drew it out into a bar, forged a 6"ish dirk fighter type blade, hardened it, and did some cutting and etching to show pattern

Thanks, Stephan...

Mike