I have also dry welded billets of stacked steel with the mill scale still on. It worked. While I was able to weld the initial stack, I had problems closing the welds after folding, or restacking. I first wondered if there was some difference between mill scale and forge scale. But, I can't find any reason that there should be. I'm just not confident enough to risk this type of weld on a billet that I have a lot of time invested in.

I have watched old silent videos of blacksmiths forge welding different items. They always continue hammering the weld area long after the welding heat was gone, then returned the piece to the fire to heat for another welding pass. Perhaps they were forging the weld area down to close it up and bring the layers of steel tightly together for the next welding pass? Closing up the material would protect it from the fire and make the fit between the material more like that of a stack of flat layers. A variable in watching the techniques of the old smiths is that they were almost always working with wrought iron. Wrought iron contains silica, which makes it somewhat self fluxing. So, I'm not certain that the steels that we are working with should be viewed with the same potential for welding in that manner.

I am also not confident that a propane forge is capable of creating the same carbon rich, reducing atmosphere as a coal or charcoal fire. I'm sure that individual propane forges have their own unique capabilities, based on their design efficiencies.

My research into forge welds really began when I started working on damascus gun barrels. The curators of the gun museums in Belgium say that the old barrel smiths did not use a flux. My first reaction was; "no way". However after some experimentation with forge welds, I am not so certain. The old gun barrel damascus was laminations of steel and wrought iron. And the smiths were using charcoal forges. Maybe they didn't need a flux.

And then; there is the fact that the old smiths sometimes DID use flux. There are all kinds of old recipes for welding fluxes. But, I don't know what conditions caused the old smiths to decide that they needed a flux. Steve McGrew, of Incandescent Ironworks, has compiled a great list of old flux recipes. Download the Word document of this list. There is a lot more information provided on it than the PDF version has.

Flux Recipes

I wish that I had more time to research this subject. It would be great to pull together a group of the best damascus smiths for about a week, to experiment and analyze forge welding.

I wish that I had more time to research this subject. It would be great to pull together a group of the best damascus smiths for about a week, to experiment and analyze forge welding.

Steve

You have a great idea!

When that happens, can I come and watch?

My background is more in blacksmithing than blades, but I can't count the times I've coached people learning to weld... By far the most common obstacle is turning the forge way up to get maximum heat and getting a highly oxidizing flame. Just learning to set the propane forge to a rich mix is magic.

I've done a little experimenting with no flux & no grinding recently and found that the scale can be converted back to steel with a long enough soak at welding temp (in a reducing environment). My success wasn't without failures though. The last billet that I did this way had some scale inclusions in it that didn't completely convert back to steel. I probably didn't allow a long enough soak before doing the first squeeze in the press.

What I decided was that it can be done but not with the certainty of removing the scale before the cut & stack. It was an interesting & informative experiment(s) but I haven't quit my old ways of welding yet <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//wink.gi f' class='bbc_emoticon' alt=';)' />.

Gary

I've done a fair amount of experimenting w/o flux, and have to admit that not using flux is by far preferable. In a controlled atmosphere and temp, the welds are by far cleaner. I do think that it is sometimes difficult to avoid white lines, or the billet coming apart despite mig/tig welding the edges/sides in the final weld for a 'w' pattern. The only exception for me is a totally dry weld where the billet is completely welded around all seams and soak time is extended. The downside is that initial billet material loss is much greater.

john