Tig welding .... single pass & multi pass

[motoxscott]

Here we can discuss the two methods of TIG welding.

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[fishd00d]

gonna need lots of popcorn for this one!

[goofballracer]

I like double pass cause if the first pass isnt so pretty double pass will clean it up a bit

just my .02

[motoxscott]

I would personally like to hear Derek's thoughts on the matter.

- Scott @ Camburg

[goofballracer]

Dump?

[Chase 2]

Seriously, why do it at all?

I'm not buying your heat argument, mulit cold passes vs one good pass. Look at the pics of Dumps work, look at the size of the heat affected area, it ain't that big.

You mentioned the TIG process being developed for air craft industry, yes it was but, I'm pretty sure it was developed for aluminum. At the time what we now call TIG (then called Heli-arc due to the use of helium as shielding gas) was being developed, the industry standard method for joining 4130 airframe tubing was plain old simple gas welding! AND that was without PWHT (that's post weld heat treating for you non-welders), and you want to talk about heat affected area? You want to talk about aircraft safety? Sorry kids, it all sounds like some guy who drives a desk put a spin on it for marketing to me.

Many times this weave people are doing is much wider of a weld than needed. For 10 extra bonus points, would some one else please inform the general public what the Welding Industry Standards aspect ratio for the height and width of the fillet as compared to the base metal should typically be?

The multi pass weld has it's place in heavy, thick material where the material is beveled prior to the joint being welded. But people, you not dealing with those thicknesses in the off road industry. Your waisting your time and money with a technique used by slackards to cover cr@ppy work.

Oh and by the way the welding industry no longer calls it TIG, (just like they no longer call it Heli-arc) its now called GTAW thats Gas Tungsten Arc Welding.

[Jerry Zaiden]

Seriously, why do it at all?

I'm not buying your heat argument, mulit cold passes vs one good pass. Look at the pics of Dumps work, look at the size of the heat affected area, it ain't that big.

You mentioned the TIG process being developed for air craft industry, yes it was but, I'm pretty sure it was developed for aluminum. At the time what we now call TIG (then called Heli-arc due to the use of helium as shielding gas) was being developed, the industry standard method for joining 4130 airframe tubing was plain old simple gas welding! AND that was without PWHT (that's post weld heat treating for you non-welders), and you want to talk about heat affected area? You want to talk about aircraft safety? Sorry kids, it all sounds like some guy who drives a desk put a spin on it for marketing to me.

Many times this weave people are doing is much wider of a weld than needed. For 10 extra bonus points, would some one else please inform the general public what the Welding Industry Standards aspect ratio for the height and width of the fillet as compared to the base metal should typically be?

The multi pass weld has it's place in heavy, thick material where the material is beveled prior to the joint being welded. But people, you not dealing with those thicknesses in the off road industry. Your waisting your time and money with a technique used by slackards to cover cr@ppy work.

Oh and by the way the welding industry no longer calls it TIG, (just like they no longer call it Heli-arc) its now called GTAW thats Gas Tungsten Arc Welding.

This is where I think you don't get it. The first pass is a very hot little rod almost fusion weld connecting the ID wall of the tube. The second pass is for filler material and the third is to finish filling and making sure the puddle is not undercutting the material.

Now go look at the process for welding nuclear tube or welding tube for the oil industry. I think after you do this research you will change your mind.

The top welders in this industry weld Robby's stuff. They are both from the Nuclear world and there welds and technique and bar-none. Both use the weave pattern and it is not for the look.

[movindirt]

Seriously, why do it at all?

I'm not buying your heat argument, mulit cold passes vs one good pass. Look at the pics of Dumps work, look at the size of the heat affected area, it ain't that big.

You mentioned the TIG process being developed for air craft industry, yes it was but, I'm pretty sure it was developed for aluminum. At the time what we now call TIG (then called Heli-arc due to the use of helium as shielding gas) was being developed, the industry standard method for joining 4130 airframe tubing was plain old simple gas welding! AND that was without PWHT (that's post weld heat treating for you non-welders), and you want to talk about heat affected area? You want to talk about aircraft safety? Sorry kids, it all sounds like some guy who drives a desk put a spin on it for marketing to me.

Many times this weave people are doing is much wider of a weld than needed. For 10 extra bonus points, would some one else please inform the general public what the Welding Industry Standards aspect ratio for the height and width of the fillet as compared to the base metal should typically be?

The multi pass weld has it's place in heavy, thick material where the material is beveled prior to the joint being welded. But people, you not dealing with those thicknesses in the off road industry. Your waisting your time and money with a technique used by slackards to cover cr@ppy work.

Oh and by the way the welding industry no longer calls it TIG, (just like they no longer call it Heli-arc) its now called GTAW thats Gas Tungsten Arc Welding.

Did not the use of gas welding effectively do the job of PWHT? The greater the heat effected area the larger heat gradient. This does not leave a sharp change as would a small heat effected area and why PWHT should be done on welds of 4130 with small heat effected area. Correct?

[CRAIG_HALL]

I'm sure most industrial pipe work welding is over 1/4" thick(oil & nuclear industry) and requires multipass welding, not necessarily a weave...I'm sure when the're weldind thineer material it's not as common. of course if we used a 1/4" tungsten and equal size rod you may be able to do a single pass.

[partybarge_pilot]

Now go look at the process for welding nuclear tube or welding tube for the oil industry. I think after you do this research you will change your mind.

All the stainless tube I have welded in fuel farms has been single pass.

The top welders in this industry weld Robby's stuff. They are both from the Nuclear world and there welds and technique and bar-none. Both use the weave pattern and it is not for the look.

Since I'm going for My weld test at San Onofrie tomorrow, I'll let you know. From what I hear, the fab shop is full of old race car builders.

I personally don't really have a preference as done properly both will work. The weave just takes longer and only happens if someone is paying for it.