Tig welding tips, questions, equipment, applications, instructions, techniques, tig welding machines, troubleshooting tig welding process
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rahtreelimbs
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    Mon Jun 14, 2010 10:39 pm

I started out MIG welding but am now advancing to TIG welding. I am just a serious hobbyist......no formal training. I always loop or weave when pushing a MIG torch. I find that this habit has followed over to my TIG welding........rather than using the dipping technique. I realize that the dipping technique is almost always needed on aluminum but is there anything wrong with looping or weaving on carbon or stainless steel???
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Not neccesarily. Jody has videos on the "lay-wire" technique, where you're weaving or walking the arc over a filler rod simply lain in the gap to be filled. I've done this quite a lot. The key here is to watch closely that the heat fully penetrates the weld; i.e. the keyhole opens as the molten filler is drawn into the puddle.

The filler rod must be big enough to fill the keyhole created, as well.

Steve
ajlskater1
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    Thu Feb 02, 2012 5:32 am

No there is nothing wrong with leaving the rod in the puddle. It just depends on the application. It comes in handing for doing like stainless piping cause it keeps that rod sheilded at all times. I use the lay wire technique all the time at work for doing our stainless pressure vessels and seals. Just got to watch the puddle and make sure you are getting penetration and not just melting the rod on top of the metal. I would practice both techniques cause there is a need to be able to do both dipping and lay wire, like trying to do the lay wire with aluminum sucks lol, it can be done using pulse or manually pulsing the pedal but the rod likes to ball up way easier than stainless rod does.
martinr
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Provided your movement is not excessive and rapid, the motion may help to get the puddle to flow and blend nicely into the sides. However, I've found that it really doesn't take much for air to become entrained into the shielding gas envelope. When I've forgotten this lesson, I've had bad porosity in steel (only visible in destructive testing where the inside can look like an Aero chocolate bar), and black peppery crap on the surface of aluminium and problems with the puddle. It may well be worse when welding in the vertical position because convection currents tend to drag air in from below.

It depends on factors such as: gas flow rate; whether a gas diffuser or a gas lens is fitted; the cup orifice size; electrode stickout; the rapidity and size (movement relative to cup orifice) of the loop/weave, whether you are lifting the electrode away too much....

Provided the loop/weave keeps the wire and electrode inside a stable, pure gas shield there shouldn't be a problem. But you'll only know that by doing some tests and destructively testing the samples with, for example, nick breaks thereby gaining confidence in your particular technique. However, the fact that you are describing an unorthodox technique suggests it could well be one that is not recommended because of the likelihood of oxygen getting into the weld.

Martin
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