I've used charcoal dust and it worked fine. The carbon between the layers is key. There are several threads on kerosene welding, under the Damascus Steel topic.

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I've used charcoal dust and it worked fine. The carbon between the layers is key. There are several threads on kerosene welding, under the Damascus Steel topic.

Steve,

Thanks for the reply. I read all the kero info when I was having little success welding with it. Still couldn't get it to work. So after watching Bob Kramer demo the process, I realized that I wasn't allowing the billet to soak long enough. That and 2250 deg made the difference. So from now I'll sprinkle carbon powder between the layers and eliminate the kero. Several yrs ago, Tom Ferry told me he was welding w/o flux and I didn't believe him. I better send him an email and eat some crow...crow w/wine <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' />

John

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Steve,

Thanks for the reply. I read all the kero info when I was having little success welding with it. Still couldn't get it to work. So after watching Bob Kramer demo the process, I realized that I wasn't allowing the billet to soak long enough. That and 2250 deg made the difference. So from now I'll sprinkle carbon powder between the layers and eliminate the kero. Several yrs ago, Tom Ferry told me he was welding w/o flux and I didn't believe him. I better send him an email and eat some crow...crow w/wine <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' />

John

Where do you find powdered carbon?

Where do you find powdered carbon?

Most pottery supply stores carry it along with red iron oxide. Probably either black or red would work. Black iron oxide at Georgies Pottery Supply in Portland is $8.00/lb.

John

You can also try Alpha Chemicals at the link here. They have red and black iron oxide and sell 5 lbs for about $15 shipped.

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You can also try Alpha Chemicals at the link here. They have red and black iron oxide and sell 5 lbs for about $15 shipped.

Mike,

That's a deal! I mixed the iron oxide into a slurry by adding water to it and by using a throw away paint brush to apply it to the billet pieces. That made the process a whole lot cleaner.

thanks,

John

You can also buy spray lubricant that is pure graphite and it works just as well. Eliminates those nasty white lines.

Got a question about comments in this thread. There is discussion about using black iron oxide, as if it was carbon. Black iron oxide might be black, but that doesn't make it carbon.

Am I missing something?

|quoted:

Got a question about comments in this thread. There is discussion about using black iron oxide, as if it was carbon. Black iron oxide might be black, but that doesn't make it carbon.

Am I missing something?

Steve,

You're probably not missing anything. I just tried it because I had it and it works. That's all I can say. I mix it into a thick slurry using water and paint it on with a brush between the layers. I like it because it's not volatile and as such, the process of stacking/welding moves a little quicker. What is the point of kerosene if not to prevent oxidation of the steel between the layers? What do you think?

That being said, I wonder if anything is needed if the stock is clean, and the soak time is adequate. I haven't had much time to explore alternatives as paying work in the shop takes priority at this point. Input always welcome.

Thanks,

John

www.gearhartironwerks.com

I just tried it because I had it and it works.

It's hard to argue with something that works.

Black iron oxide is Fe3O4. Essentially, magnetite. I've done some research on mill scale and forge scale. They are essentially the same thing. Magnetite is the primary component of forge scale and mill scale.

It seems counterintuitive to introduce to a forge weld the material that you wish to avoid. I could only assume that making a slurry of the black iron oxide creates a sealed anaerobic condition between the layers of steel. The temperature and reducing atmosphere of the forge fire is either enough to extract the excess oxygen molecules, or somehow causes them to be assimilated into the layers of steel.

I have forge welded layers of steel that still had mill scale on them (only as a test). The welds were sound and I could not see any visible difference in the welds, compared to welds made on clean steel. I read somewhere that the smiths who make kris blades prefer to have their steel very rusted before forge welding. If it isn't rusty enough to suit them, they will bury it in the ground to rust it more. I don't know if this is fact. But, it is food for thought. Perhaps we don’t know enough about what exactly happens during a forge weld.

Almost all of my forge welding is done on cleanly ground steel with kerosene, or the layers are tightly MIG welded shut.

Steve,

I used to meticulously grind all the mill scale off of my steel before forge welding billets as well. Then a MS (who shall remain nameless) looked at me and said "why are you wasting all that time and steel? The flux will clean that scale off when you get it to temp." When I went to using diesel (instead of kerosene) I wondered if it made a difference. So far it hasn't mattered whether I use steel with mill scale or not. Then again, even with the fuel gas, I still use a little flux to read the heat of the steel before welding. Maybe the flux provides the cleaning, the fuel gas provides the extra carbon, and using both is the best.

I certainly fall into the category of someone who "don’t know enough about what exactly happens during a forge weld." I just know what works for me.

I always grind off the mill scale, but have never worried about removing rust.

At our hammer in weekend before last I watched J D Smith weld several billets with NO flux or carbon adding fuel on billets I prepped and using my forge press and air hammer. He is calling this method Bareback welding and all it requires is a reducing atmosphere in the forge.

What seems to be happening in this method it that the carbon necessary to form CO2 and strip the oxides front the surface comes from the steel it's self. This is can be seen if the billet is cut polished and etched after the first weld (with out much drawing of the bar) a very thin line can be seen that etches very brightly, brighter than the 15m20. I think this is due to decarb around the weld boundary, this disappears after forging due to carbon migration and is only a few thousandths wide to start. Using this method the welds are flawless and very strong even after only a single pass, just as with the Kero welds.

MP

|quoted:

At our hammer in weekend before last I watched J D Smith weld several billets with NO flux or carbon adding fuel on billets I prepped and using my forge press and air hammer. He is calling this method Bareback welding and all it requires is a reducing atmosphere in the forge.

What seems to be happening in this method it that the carbon necessary to form CO2 and strip the oxides front the surface comes from the steel it's self. This is can be seen if the billet is cut polished and etched after the first weld (with out much drawing of the bar) a very thin line can be seen that etches very brightly, brighter than the 15m20. I think this is due to decarb around the weld boundary, this disappears after forging due to carbon migration and is only a few thousandths wide to start. Using this method the welds are flawless and very strong even after only a single pass, just as with the Kero welds.

MP

OK, you convinced me to try it...again1 <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' />. I actually did inadvertently but never followed up because I was so focused on the kero dunk at the time.

Thanks,

John