tips on forge welding

[781]

In a gas forge use a touch rod. This is a thin rod say 3/16 not sure the metric equivalent. Heat the piece you will weld to the color you are going to weld at leave this in the forge bring the rod up to the same color and touch the piece it should stick enough to pull the piece in the forge if it will not stick in the fire it will not weld on the anvil

[Black Frog]

I do a lot reading and watching as I'm trying to soak up as much info as possible with me being so new to this.

When I'm reading up on preparing to weld, I see Mark's nice video on the subject:

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And his scarf and weld positions are like shown in the picture below.

On the other hand in Randy McDaniel's book, "A Blacksmithing Primer" on page 117 talking about forge welding he shows the scarfs almost the opposite way. So that the two angled scarf faces are lapping each other.
Is one way considered more 'right' than the other?

[iron woodrow]

6 of one, half a dozen of the other.
basically you are thickening the two parts so they can be brought back to the same thickness as the parent bars..... without making it too thin

[Frank Turley]

Kung Fuzed? Each smith probably has his own way of making lap welding scarfs. Mark gives some good tech info, but not everybody makes his style of scarf. Mark's first shown scarf is what I call a "simple scarf." I believe he laid it back on itself flat to flat, but that isn't shown. His later, lapped scarf has the little 'sharp step' in it and flat faces, all of which could be dirt trappers, if one is not careful. "The Blacksmith's Craft," an English book, shows scarfs similar to Mark's, but with a radiused shoulder and a longer "toe."

Personally, I've taken my clues from two books, Schwarzkopf and Harcourt.* Both books can be Google/downloaded. Schwarzkopf shows a rounded, rockered face on the scarf, the idea being that when the two faces meet, they are tangent in the center at first contact. This tends to squeeze/press the fused scale and flux out as one hammers. Harcourt has some very nice line drawings, especially when showing the lap welding together of two round-sectioned bars. The scarfs are narrowed to a soft point at the toe by tapering the sides of the scarf. This is to prevent the sideways spread of the thin "wings" or "ears' which would develop if the scarf were wider.

I saw Francis Whitaker make lap welding scarfs one time, and he roughened the faces by putting multiple transverse indentations on the faces with half face blows at the near anvil edge. He got the weld.

One must pay attention that there is some upset material beneath the toe (point) of the scarf. If not, a weld may take place, but the result may have a thin place either side of the weld.

*
"Plain and Ornamental Forging" by Ernst Schwarzkopf
"Elementary Forge Practice" by Robert H. Harcourt

[Glenn]

Try them all, not once, but try say 25 welds using each method Learn the method and technique and why it works or does not work.

The perfect scarf pattern is the one that works for you consistently. Realize that no one method will work for all welds, That is the reason to learn each method and why it works.

[Francis Trez Cole]

I found this information very important

http://www.youtube.com/watch?v=8jZDEtmDgxI&feature=plcp

[brianbrazealblacksmith]

Exactly, Francis! I have been talking about this for years, and that is why I have been stressing the "forge welded bundle" and the "blob weld" especially when forging A36. Most "traditional scarfs" do not allow for enough forging to secure the weld and if tested they would come apart. It is just like clay, if you cannot smash it together enough to make it one piece, it can and will peel away if put under stress.

[wolfman6]

has anybody ever forge welded wrought iron? I was also wondering it can be forge welded with other metals like 15n20 to make damascus?

[Dave Budd]

anybody weld wrought iron? Only pretty much EVERY smith for the best part of 3000 years! :D

wrought is a varied material, some nice and some not so nice to work with but generally welds very nicely. Welding it to steel takes some practice as the wrking temperatures are different. It does give some very nice effects and textures though ;) Best advice is to give it a go and see what happens

[Timothy Miller]

That's like asking if anybody has ever eaten food.

[george m.]

I've been told that as a general rule wroght iron is easier to forge weld than steel because it is self-fluxing due to its higher silica content. I don't know if that is true but it is what I have heard.

That was the original reason for pattern welding (often inaccurately called "damascus"). It allowed the supply of rare and expensive steel to be stretched by layering it with cheap and available wrought iron. The decorative possibilities were just a nice icing on the cake. Once decent qulity steel became more available pattern welding dropped out of use, at least for sword blades.

In flux,
George M.

[Pault17]

That sounds about right George. Give it a whirl, see how it works, then show the rest of us

[Steve Sells]

I've been told that as a general rule wroght iron is easier to forge weld than steel because it is self-fluxing due to its higher silica content. I don't know if that is true but it is what I have heard.

That was the original reason for pattern welding (often inaccurately called "damascus"). It allowed the supply of rare and expensive steel to be stretched by layering it with cheap and available wrought iron. The decorative possibilities were just a nice icing on the cake. Once decent qulity steel became more available pattern welding dropped out of use, at least for sword blades.

In flux,
George M.

I disagree. it was not layered to stretch steel but steeling the edges was done for that reason. Pattern welding is done for looks, even tho folding has other uses, they are not exactaly the same, its semantiacs. I have no idea where you get the idea that pattern welding has fallen away, it is still used for sword blades. I myself do most my swords in pattern welding, Therefore I think your information is false on most counts

[Timothy Miller]

forge welding is inherent to the production of wrought iron. Forge welding is the methoid of choice for joining wrought iron for centuries. Forget modern metalworking when you are thinking about wrought iron.

[thingmaker3]

One thing to remember is that WI has a much higher welding temperature than steel. The trick is to manage the fire and the metals to get both of them at the right temperatures at the same time.

For a PW billet with steel and WI, you risk overheating the steel. Keep an eye on what you are doing and make as few folds as you can get away with. Keep the WI on the outside.

I've seen some very nice pieces made this way.

[MOblacksmith0530]

Haven't tried it with 15n20 but have welded it to mild and tool steels many times. take care to follow the leads above in managing your fire and heat they are dead on.

[george m.]

Dear Curmudgen,

While there has been a renaissance in the manufacture of pattern welded blades in the 2d half of the 20th century the use of pattern welded blades had pretty much fallen out of use by the mid- to later middle ages with the increased availability of steel. The occurrence of pattern welded blades in the archeological record is much commoner in the early middle ages than later.

I figure that it is the same time/labor equation. If a smith can make a single pattern welded blade in say, a week and can make a solid steel blade in 2-3 days and the solid blade will sell for 80% of the cost of the pattern welded blade the liklihood is that the smith will turn out more solid blades. Also, in a workshop it is probable that only the master and a few journeymen are going to be skilled enough to produce pattern welded blades. If a customer wanted a pattern welded blade and was willing to pay the extra it would be done but the run of the mill output would be solid steel blades.

I will post some references in the morning.

Yours,
George

[Frank Turley]

It is true that wrought iron can withstand a higher welding temperature than most steels, but wrought iron can also be welded at the lower, sweating, non-sparking, welding heat. Witness all the edge tools made in the old days. The tool bodies were wrought iron and the high carbon steel was bird's-mouth welded in as the cutting bits, all done at the lower welding heats. High carbon steel crumbles and cracks at a too high welding heat.

[trying-it]

Wrought iron can also result in wood grain textures on flats and cable looking strands on end grain.

This is wrought and mild over 3" sq X over 5" tall. A 16-hr strong acid etch produced and shows the desired wood grain look and cable strand looking ends while the mild remains untouched by acid. Forced rust patina and clear coat provides the wood looking color. (will be a desk lamp base soon)

Stan

[tomhw]

It is true that wrought iron can withstand a higher welding temperature than most steels, but wrought iron can also be welded at the lower, sweating, non-sparking, welding heat. Witness all the edge tools made in the old days. The tool bodies were wrought iron and the high carbon steel was bird's-mouth welded in as the cutting bits, all done at the lower welding heats. High carbon steel crumbles and cracks at a too high welding heat.

Yes, I agree, Mr. Turley.

As for pattern welding, it is a decorative technique today but, in ancient times, was a mechanical way of producing a tool with a hard edge with a resilient and flexible body. centuries slow progress of steel metallurgy resulted in differential quenching, differential carbonization, and other techniques that made pattern welding obsolete. Never-the-less, the glamour of "Damascus steel" lead, in the 19th century, to the development of scientific metallurgy.

Though it is no longer mechanically necessary, pattern welding, and wootz, produce the most inetresting and most beautiful blades.

[Dan P.]

I always suspected that the "wrought iron must be welded at a higher temperature" theory came from old farts who weren't that good at welding to begin with.
Does anyone remember the "you can't fire-weld mild steel" theory? I think it probably came from the same place, but was just harder to sustain.

The main thing wrong with welding wrought to other things, particularly when it comes to pattern welding, is that wrought is much softer and will give you problems because of it.

Pertaining to the timeline of pattern-welding, its disappearance or otherwise, one book will set everybody straight; Damascus Steel, by Manfred Sachse.
It's a book that shows how pattern welding has been in constant use in continental Europe since the 18th (?) century, and presumably a long time before that, and is fully illustrated with examples. It's a book that should put to shame any idle boasters claiming to have re-discovered pattern welding!

[ThomasPowers]

Ok lets start at the beginning: early wrought iron was made with the bloomery process where the metal never really melts but forms a sludgy mass in the bottom of the furnace filled with slag, charcoal, un reduced ore, furnace wall materials, etc. This bloom can range anywhere from pretty much zilch carbon to cast iron. (Note that the Japanese Tatara furnace is a bloomery process.)

Repeated stacking, forge welding, and drawing out is used to "clean up" the bloom each cycle reducing and fining the silicates embedded in the iron mass. As we now know repeated forge welding cycles also tends to make the material more homogenous both in silicates distribution *AND* in carbon content.

Every culture I have researched that used the bloomery method of making wrought iron also seems to have come up with pattern welding whether on their own or from technological diffusion. Pattern welding in early blades was a symbol of "high quality work" showing that much time and effort was expended to make it. It also helps with the diffusion of carbon in the piece to avoid overly soft and hard areas. It also helps stop the propagation of cracks at layer boundaries.

"The Metallography of Early Ferrous Edge Tools and Edged Weapons", Tylecote and Gilmour; has a nice example of an early European blade that was made from 13 individual pieces of which 5 were pattern welded billets, (6th century IIRC). Also see "The Celtic Sword", Pleiner, for examples of piling morphing into pattern welding.

Pattern Welding in Europe pretty much died out around the year 1000, ("The Sword in Anglo-Saxon England" H.R.E. Davidson), with better more uniform steels becoming available for as we all know each weld has also the possibility of being a cold shut or inclusions and so it can decrease the strength of a blade compared to a more homogenous material one. However the making of shear steel from blister steel is pretty much a simple pattern welding process---which again allows for a more uniform carbon content. ("Steelmaking before Bessemer", vol I Blister Steel)

Having an applied harder edge material dates back even before the quench hardening of steel was know, Pleiner's shows multiple examples where higher carbon *or* phosphorous edge materials were welded to blades that were not heat treated. This technology extended until comparatively recent times---I have examples of late 19th century tools with wrought iron bodies and steeled edges or impact surfaces. (steel could cost over 5 times that of wrought iron even as late as the American Civil War!)

Pattern welding was again used in making gun barrels---the resistance to propagating cracks being a good thing here. It was also played around with decoratively around the time of the French Revolution and experienced a renaissance during the folklore nationalism of the early 20'th centuries. The Hunting and Fishing Museum in Munich Germany has a number of very well done examples made during the rise of National Socialism.

Now if you want to try your own bloomery "The Mastery and Uses of Fire in Antiquity", Rehder, has "foolproof" plans in one of it's appendices.

I strongly suggest you read "Sources for the History of the Science of Steel", Cyril Stanley Smith, if you believe that scientific metallurgy was the result of 19th century interest in Damascus steels. It covers the search for what makes iron into steel which culminates in quite rigorous experiments in the *18th* century resulting in the discovery in 1786 that it was *carbon* that makes iron into steel---a very sound foundation for "scientific metallurgy" that had nothing to do with Damascus Steel and occurred the previous century...

The first edition of "Decorative and Sculptural Ironwork" has several examples of wrought iron pattern welded with pure nickel for very pretty *non* blade uses.

[basher]

nice and thorough write up.
I make blades from wrought iron mixed with 15n20 and 10 80 /1095 equivalents and as stated above you have to choose a temperature/flux and forge atmosphere that will meet the multiple material requirements of both the materials to be forge welded.
and yes wrought iron is much squishier than steel.
wrought iron sits on the gas forge/coke forge boundary as far as heat requirements go.
wrought iron is not "a" material. it can be all sorts of materials varying in carbon and silicates and other impurities.
whilst smiths may have been sad at its demise engineers must have celebrated the coming of mild steel.

[ThomasPowers]

But look at all the fun they had in the 19th century trying to cast the largest cast steel ingot! (Mention of this can be found in "The Arms of Krupp" including Krupp cutting a chunk off an ingot that was accused of just being cast iron and forging it as cast iron *doesn't* forge...)

Two *very* *good* lines that bear repeating!
"wrought iron is not "a" material. it can be all sorts of materials varying in carbon and silicates and other impurities.
whilst smiths may have been sad at its demise engineers must have celebrated the coming of mild steel."

[tomhw]

"Ok lets start at the beginning:"


Well said, Thomas. The literature and tradition of ironwork spans millennia. I have not read it all- not nearly, but I still read and still forge. Anyone who wishes to learn this craft should read everything and hammer daily.