Tig Debate???

[balerjoe]

I work in a milk process plant which we are currently under expansion. We have some really good tig welders here from all over the US. I've read here on the forum that the proper way to use filler rod is dab and move I've even seen some nice pics that Andy made where this was done. But all the guys here say not to use filler that way. They have shown me all you need to do is start your puddle slowly bring your filler in and move along inserting the desired amount of filler. There welds come out nice. I've tried the dab technique but I my welds just don't look a good as when I leave the filler down and move it over letting the heat suck the filler into the weld. But my question is my way the right way or am I making a cold weld. If the contrast is true way are some way I can improve my filler ability?

[HAWK]

balerjoe,

There a several ways to do it:

1) Start the puddle, add filler, move the torch forward, add filler,
move the torch forward, add filler, etc. Keep the filler within
the gas envelope or totally away from it to minimize oxidation.

2) Start the puddle, put your filler in the puddle and push it in as
as you advance the torch. Always keep the filler in the puddle.
I use this method on hard to weld alloys and some fillets. A
VARIATION OF THIS SOUNDS LIKE WHAT YOUR CO-WORKERS ARE DOING. IT
SOUNDS LIKE THEY ARE KEEPING THE FILLER WITHIN THE GAS ENVELOPE,
BUT ONLY ADDING FILLER WHEN THE JOINT APPEARS TO REQUIRE IT.

3) Walking the cup is a variation of the above technique where you
"walk" the cup from side to side while advancing it forward and
keeping the filler in the arc at all times. This works well on
fillet welds, but is best reserved for pipe welds. As your bevel
in the pipe joint becomes smaller due to the addition of filler
metal a smaller cup will be necessary for each weld pass in order
to continue walking the cup until the joint is completed.

4) Start the puddle, pull the torch back and simultaneously add some
filler. advance the torch, again pull back the torch and again
add filler at the same time. This is an older method and is not
very common anymore. The bead results are typically somewhat
less appealing than welds made with method #1.

There is no wrong method here. All these are valid methods taught in GTAW schools. Many times it is personal preference. Sometimes the method is dictated by the material and joint type such as "walking the cup" when pipe welding or using the technique your co workers use when producing a structurally sound weld with a flatter profile. This can be useful when dye penetrant testing is required since they are no prominent freeze lines for the dye to become caught in.

I hope this helps.

[Canuck]

In school I had the chance to work with an amazing welderthat did this. I watched him do stainless pipe like this. All he did was get a puddle and lay the rod over the joint and wash it into the sides of the pipe. Mind you this was beveled sched 40 pipe which is much thicker I would think than what you do in the dairy plant. All of these welds passed the bend tests performed on them.

[HAWK]

Canuck,

I use it on sched 10 SS through Sched 40 API5lXXX pipe. It is easier to grab and maintain a rythym on the sched 40 pipe since it is thicker and I try to make 3 passes with 37.5 degreee end bevels.

[Canuck]

Hawk

When I watched my friend do it he also did three passes but used a 30 degree bevel. Thanks for the reply.

[ASKANDY]

balerjoe,

Welcome and good question!

Been out on vacation this last week. Came back early. I see I missed quite a few topics!

Anyway,
How I decribe the dab-move method is to get people into a rhythm. As you improve on rhythm, you pick up speed and soon you do not even need to stop when dabbing, just keep moving along the joint dabbing filler into the open root. It takes more practice because you are moving along a bit faster and it's easy to over-run yourself. Some people even lay the filler in the joint and move the torch across the joint and filler at the same time giving a smoother bead appearance. I'm not a fan of this proceedure unless you are welding thin enough material to get proper root fusion.

Hope this helps.

A-