This is from a post July 2011 "Keroseen VS Flux"

I put together 2 billets of 01 and 15n20 (small stack 8 pieces each) today and I did not clean the scale off the 01 before tacking it together. I let them cool and sprayed one down with WD40 and the other did nothing to it. I brought them up to welding with a rich flame in the forge and put them under the hammer to set the weld. Both billets had a solid feel so back into the forge for a soak then back under the hammer for another set, no edge forging at this point then back into the forge for another soak. Third go round I got after them hard and aggressively drew them out and straightened the edges out. The billet that had the WD40 had zero problems and the "dry stack" had just a little area close to the edges that did not take. Both billets were then ground clean with a side arm grinder, cut, restacked and rewelded in the forge in the same manner described above with the same results. Conclusion; you do not need flux to forge weld as long as you have the proper atmosphere and technique. I believe the addition of WD 40 or kerosene makes it even easier and should prevent potential flux inclusions.

Bob Kramer

Here is a picture of the test billet, materials 15N20, O1, 1080, no borax used only WD 40 (The other billet was dry welded no wd 40)

Hi John,

Thanks for the nod about Western States. Interestingly enough I just saw JD 3 weeks ago at Zack Jonas's place where I introduced him to the idea of dry welding. He had a hard time believing it until he tried it himself. The next thing he said was " I'm teaching this next weekend". In all fairness it's not my idea. Back in the early 2000's Matt Disken had a hammer in and I was teaching basic Damascus and Jim Batson was overseeing the demo. I had just fluxed my billet in the forge which was the way everyone was doing it at that time. As I stood back and waited for the billet to get hot enough Jim slid up next to me and said very quietly " you know you don't even need flux". The way he said it I thought he was pulling my leg and I put it out of my mind. Cut to 8 years later, and we where having trouble with inclusions in our Damascus at the shop and I could not figure out what was going on. I futzed with everything and still inclusions. Then I realized that we had just gotten a new bag of anhydrous borax and I suspected that was the problem. Dr. Batsons voice came a calling from the past and so I thought what the heck I'm going flux less , dry ,nada, nuttin. Strangely as I put the billet into the forge I was afraid. I realized that I had been doing it this way ( with flux) for 14 years and everyone else I knew did it that way too. I guess my fear was it's not going to work, it can't work, this is not the way it works. Well it worked as you already know. It will even work with mill scale on. It will not work with forge scale on, at least not for me. Tig welding the seams will also work but it's not needed for simple steels . In industry, like Hitachi, where they are making stainless Damascus they Tig the edges. My experience is that as long as you set the weld properly the first time you don't need flux. Once in awhile if I'm a pinch too aggressive on the first weld I'll flux the edge just for insurance. In my opinion flux is a contaminant that is used in a pinch.

a rare check in here for me. Yes indeed, Bob demo-ed that technique for me when last I saw him. I was duly astounded. The following week was spent amassing as much info as I could on practical considerations and best practices for this method of forge welding. I tried just about every contingency; Mill scale on...Mill scale removed; Forge scale on...forge scale cleaned off, reducing forge ...oxy rich forge, setting welds in the hydraulic press, at the hammer, in a leg vise etc. and MANY other scenarios. I now have a set of best procedures that insure the success of this technique 100% of the time. Up at the "Dragon's Breath Forge" hammer-in, a few weeks ago, I demo-ed my findings before a gathering of interested bladesmiths. I developed a sizable billet of "W's" at a high layer density all without a single drop of flux or oil of any kind. Needless to say this astounded the onlookers much, as we've all been told for years just how essential flux is to insure good welding. NOT true. In fact, it isn't at all necessary.

When I've organized my findings a bit more to write it all down in a format we can all understand, I'll get it out there on the forums. I've dubbed this technique " Goin' Bare-Back".

Bob,

Thanks for the response. I had a much better day on Sat and made a 15 layer billet of 1095, 5160 and L 6. I welded dry and had 2 minor edge issues in the billet that is 18 x 2.25". I was kind of proud of myself and enjoyed a couple of shooters of single malt scotch after. I'll post a pic when I get to the shop on Mon.

This has been a real learning experience for me and I certainly appreciate the helpful suggestions.

John

I want to express a big thank you to both Master Smiths Bob Kramer and JD Smith for taking the time to share their considerable knowledge and expertise.

I have to say that it is refreshing to see so many ABS members that are willing to share the skills that they have worked hard to learn and master with others to advance and promote the ancient craft of the forged blade. I believe that it is this generous sharing of technical information that sets the American Bladesmith Society apart from other organizations and is largely responsible for our continuing growth.

How it all works

Hitherto we've all pretty much accepted flux as a necessary evil. The borax based flux commonly in use works a solvent to dissolve oxides and some other noncombustible surface contaminants. After it's been applied it liquifies and capillary action allows it to penetrate voids and crevices. and if all goes well the liquid borax along with it's dissolved oxides etc. get ejected when the steel is struck or pressed, leaving clean metal surfaces to touch without oxide barriers allowing the bond. Problems occur when the flux gets trapped in small pockets that prevent it's escape. we all know the ugly boogers this causes. Even the most experienced among us experience this from time to time.

Welding without flux or oils simply utilizes the the chemistry of combustion to do the heavy lifting. All we do is simply step out of the way and allow the metal to do what it only naturally does.

Fire as we've all been taught needs three things ; Fuel, Oxygen and Heat. Remove any one of these from the equation and combustion ceases. creating a reducing atmosphere in the forge environment starves the fire of vital oxygen. The chemical reaction of combustion begins to seek oxygen from any available source, namely in this case, the oxides on the metallic surfaces, depleting them of oxygen and reverting them back to iron which is now quite hot and in a highly energetic state. In this energetic state the atoms of iron will undergo co-valent bonding when brought in close proximity with a neighbor. That is, two adjacent atoms will share their outermost electron orbits forming a bond. the fluxless method appears to form many more of these bonds much quicker. I can set a primary weld in a leg vise with this method and go straight to hammering the billet 90 degrees from it's original orientation with no fear of shearing layers. That is a FACT. Even the incompletely welded edges I'm able to close up completely with out the use of flux.

In the language of chemists, we are creating what is known as an Oxygen Reduction Reaction.

Thank you J.D. and Bob. Great information and I will be trying this out. Welding without flux would be great, both for me and my forge. Thank you again for all your work and the willingness to share it.

Brion

JD's demo did in fact blow my mind a bit, until I got my head around what he was doing ( and JD thank you SO much for demoing at our hammer-in!)and realizing that the chemistry is similar to making steel from Ore in a direct reduction furnace (bloomery).

My thoughts after having a bit of time to think about and talking it over with my business partners, the bare-back method works and works well. How well it works for everyone will I think be contingent on a few things, the reducing atmosphere at high temps in the forge is a must and some forges will work better than other for it(In general I think it will work better with venturie burners rather than blown)and I don't think you could repeatablely do it in a coal or charcoal forge.

A few other types of welds I think will still require flux (welding the eye on tomahawks, welding the tip and edge on traditional Viking sword, etc) but how much this method speeds up and simplifies the whole process of making a billet is just incredible!

MP

I also want to thank Bob and JD for their input on this topic!

JD, I very much am interested in hearing more about your best procedures. An area of particular interest to me is your findings on welding with mill scale vs. forge scale. I've been quite successful at welding billets with mill scale on the pieces, but welding with forge scale has defied me. I haven't found a good explanation for this.

At the 2012 Heartland Bladesmithing Symposium, I was scheduled to do a demo on forge welding with kerosene. Right after being scheduled for this demo, I had some time to experiment with forge welds and successfully welded up some billets without flux or kerosene. I could no longer in good conscience do that demo and tell the attendees that welding with kerosene was the best method. I wound up demonstrating a kerosene weld as promised, but went on to weld some dry billets that still had the mill scale on them. My message to the attendees was that there was more for us to learn about forge welding.

Also thanks again. J.D. I was also wondering about your setup. Do you clean the steel or leave the mill scale on? Also, are you welding the sides with a welder before. I will be trying some myself and will see what happens.

Brion

OK, let's get down to brass tacks.

Mill scale seems to offer no obstacles to welding. Sides need only be tacked in such a way as to prevent and minimize layers bowing outwards as the billet heats up...use a low current to prevent deep penetration of your weld material.

If the faces to be welded are well planished and flat, thin layers of forge scale will work if they are allowed to sit in a reducing atmosphere for a bit longer. This takes more than one heat to set the weld properly. Cleanly finished surfaces work the best though.

so far I've worked this at relatively higher temps (2000F+) I will be making more attempts at establishing a lower temp range; more like borax welding temp ranges. I've also determined that process will work with atmospheres that aren't all that reducing; as long as you've got at least 3-4 inches of plumes emanating from the forge opening, you're good to go. with forge scale you need to choke it way back ...that is starting with a very hot forge, then choking the fire back once you've gotten the billet heated through and evenly and letting it soak there for at least 2 full minutes with a long plume out of the forge . It will weld with light forge scale. This seems to be a function of the thickness of the scale. thicker scale means more soak time in a reducing flame. Get this technique down pat and you'll find yourself taking MUCH less time to complete billets, if for no other reason than that there are no problems along the way( bubbles, voids, de-lams, etc), you just move straight ahead.

As well, setting the welds in your Hydraulic press is the best way to go, alternately doing it under the hammer will work as well, but you must not cream that billet on your first few hits, just give it a few love taps , front to back. On your very next heat you should hit it a bit harder; on the heat after this, you should be good to draw it out from any direction or orientation without failures.

|quoted:

JD's demo did in fact blow my mind a bit, until I got my head around what he was doing ( and JD thank you SO much for demoing at our hammer-in!)and realizing that the chemistry is similar to making steel from Ore in a direct reduction furnace (bloomery).

My thoughts after having a bit of time to think about and talking it over with my business partners, the bare-back method works and works well. How well it works for everyone will I think be contingent on a few things, the reducing atmosphere at high temps in the forge is a must and some forges will work better than other for it(In general I think it will work better with venturie burners rather than blown)and I don't think you could repeatablely do it in a coal or charcoal forge.

A few other types of welds I think will still require flux (welding the eye on tomahawks, welding the tip and edge on traditional Viking sword, etc) but how much this method speeds up and simplifies the whole process of making a billet is just incredible!

MP

Matt,

I've already done some very successful multi billet work goin' "bare-back". this week I'll be trying it on welding the bit to the cheek of an axe one of my students is building. I'll check back in on that later here.

well I do hope you prove me wrong!

Okay, I made up a billet , 9 layers, of 1084 and 15n20. Fired up the forge, mine is venturi, and adjusted the mix for a reducing atmosphere. The billet was brought up to heat and allowed to soak. Then to the power hammer and presto, light hits and a welded billet. No flux or kerosene was used, totally dry, mill scale left on. I did do two heats for welding. Then flipped the billet 90 degrees and hit on edge, no delaminations at all. The billet has been drawn out. Needless to say my method of making damascus has just changed. No splatter, or borax powder flying around. Thank you Bob and J.D.

Brion