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What electrode to use on wrought iron?

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Note that fusion welding of wrought iron doesn't result in wrought iron but in cast (low carbon) steel as the silicate stringers that affect so many of the properties of WI will float off as slag.

These same stringers are what makes modern welding of wrought such a pain as they melt at a lower temp than the metal and makes forge welding easier as they act as build in flux. (and note forge welding is at a lower temp than fusion welding)

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No I was suggesting nothing; just pointing out that fusion welding of Wrought iron gives you a different material. I would have to know what the problem actually was before making a suggestion and even then it might end up being to braze a mild steel wear piece to the wrought iron.

The Byers book on Wrought Iron speaks about arc welding it. If I get a chance I'll reread that section tonight. I've only forge welded it myself but have a weldor friend who has quite graphic and profane comments on trying to fusion weld the stuff.

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When I posted this question I capitalized certian words hoping that I would not have to explain every detail of the repair job I face. I said arc welding was my ONLY choice and this is why. The gates were cut free of the stone posts at the hinges with a torch, not by me I might add. The eye of the hinge was split like a Babbitt bearing cap. The gates will be painted before installation. Even if arc welding had not been invented yet, forge welding is out of the question. Half of the hinge is still in the post. The weld has to be made with the gate and hinge in place. Gas welding would take a long time and a LOT of heat. There are four vertical butt weld joints in 3/4" X 2" flat bar. Now, back to my original question, Is there anyone who knows the proper techinque for arc welding wrought iron with a stick machine? It was mentoined to use 6010 6011 7018 or 7014 to do the job. No doubt all of these rods will stick it back together but is one better than the other? What about a nickel rod? These welds will hold all the weight of the gates, about 500 LBS each. I guess what I would like to hear from someone is, "Use a XXXX rod. It has been tested and produces high strenght welds in wrought iron" Thanks for all the answers so far. Danny

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Hey DannyD,
thanks for the question. Imagine if you asked a bunch of veterinarians what brand of shampoo works best for a wooly mammoth. They will all have an idea or opinion. Some may have even washed a wooly mammoth. But without the proper or at least some of the information, you will get a bunch of different answers.

Your second post filled in a lot of blanks. The gates are big, heavy and have to be welded in place while held in place. Sizes of material and look of the final finish open up different avenues of possibilities. Brazing would be a great lower temperature choice and the strength is there. As Forgeman said, 7018 would work and the strength is there. Tig is also a good choice for very localized heat and, if you have the ability or provisions, you could use WI as the filler and gain benefits of not adding any foreign material to the weldment.

As for pictures, we just love pictures. and any pictures of 'old" stuff is generally welcomed.

Oh Yeah. if you told us wehre you were located, there might even be somebody nearby that could provide better assistance too

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"Wrought Iron, It's Manufacture, Characteristics and Applications" James Aston and Edward Story

"In welding WI by the electric arc process the best welds are produced when the welding speed is decreased slightly below that used for the same thickness of soft steel. This procedure is desirable because with reduced speed the pool of molten metal immediately following the arc is kept molten for a longer period of time, thus making for a more complete elimination of the gases and affording the entrained slag an opprotunity to float out of the weld metal.

Also it may be necessary to employ a slightly lower current value than is used with the same thickness of mild steel, particulary in welding thin sections where there is a possibility of burning through the material.

Excessive penetration into the face of the parent metal should be avoided. The penetration should be no greater than that required to obtain a sound bond between the deposited metal and the parent metal, because fusion of an excess quantity of the parent metal tends to carry slag into the weld metal.

Any good quality low carbon rod either coated or bare can be used with wrought iron, but in general the coated rods are used more extensivelly in current installations."

In the O-A welding section it suggests using a rod with the same tensile strength as the WI (27-30 Kpsi)"

There is also tables of suggestions for joint prep, spacing, number of passes, size of electrode, rate of travel, etc.

This book was published by the A. M. Byers Company who commercialized the last major method of making wrought iron---they have a lot of experience with mamoth washing.

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I would avoid 6010/6011 because of the strong gouging arc. When WI is arc welded and the slag floats out, it shrinks a bit and this sometimes causes undercut.

Personally, I would consider 7018 with a cap of 6013 which is a low penetration rod that gives a very pretty bead. I would also think about welding downhill since this puts less heat into the weld.

It would be good if you could experiment on a piece of scrap WI in a similar configuration but I realize this may not be possible.

Oxy acet. would be my choice. Perhaps using some soft tie wire as filler rod. That stuff has very little carbon. Oxy acet is not that slow especially when you have to set up for just a couple of welds. But then I am not looking at the actual job so I cant really judge.

Do not use Wild & Curly shampoo to wash the mammoth. You will never be able to comb him out and he wont fit thru the bathroom door.

Edited by maddog
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  • 7 years later...
On September 3, 2008 at 3:47 PM, ThomasPowers said:

Few indeed will be the welding supply places that know what real wrought iron is; most will tell you it's mild steel.

Very true.

Most guys at welding supply stores have no experience.

I have had great luck stick welding wrought iron.

I use a small rod 3/32" 7014 or 7018

Also run at the low end of the heat. Just enough amperage to keep the rod from sticking.

Really watch the puddle and react accordingly. The slag formation behind the puddle will be a little different than welding mild steel, but you will get the hang of it.



Another key thing I have found repairing wrought iron is the prep work.

Clean the joint with a wire wheel.

The cleaner the better.

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  • 1 month later...

6013 will mix better than a 7018 lohy you will be doing a lot of grind then weld grind then weld as the interlayers float out 

Nothing will be truly structural after electric welding of proper wrought iron. Take care what you promise and take on 

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Audel Welders Guide suggests "O-A with a neutral flame and low carbon steel welding rod will produce high quality welds", "Attempts to use high carbon steel welding rods to increase weld strength should be avoided"

Wrought iron, Its Manufacture, Characteristics and Applications suggest that for arc welding speed is decreased and a lower current is suggested avoiding deep penetration into the base metal.  It also provides a table on welding details.

I would NOT suggest using wrought iron as a filler material as you are already having to deal with the slag in the weld adding more is contraindicated (the slower speed suggested for arc welding is to keep the puddle liquid longer to allow the slag to float to the top!)

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