Determining number of passes, weave or not - GTAW

[Welder Dave]

The welds look good but it would have been better to weld inwards from both ends so you don't leave the crater at the end. The crater is a potential site for a crack to develop. This can be important on critical welds. I'd consider steering components fairly critical.

[husq2100]

The welds look good but it would have been better to weld inwards from both ends so you don't leave the crater at the end. The crater is a potential site for a crack to develop. This can be important on critical welds. I'd consider steering components fairly critical.

Fair point. I do think a good welder could do it in one go in one direction though.

[husq2100]

The second one (for the other side) came out a touch better. Well the weave did on tab, my fillets weren’t as good on this one .... one day I’ll get all my good welds on one piece lol

[husq2100]

Regarding amp control and being able to drop or cool towards the end of a weld run. I have downslope, 0 - 15 seconds. Now as far as I can tell , let’s say I set it to 5 seconds, then I have to guess/know when I’m 5 seconds from the end of weld and let off the switch... seems like something that will take A LOT of practice??

[Showdog75]

140-180 amps probably. Lap joints takes less amps then the other welds with the thicker metal. Leg height should be 3/4 to the full height of the thickness of base metal to be considered structural and leg height no taller then the thinner piece of metal if there’s 2 different thickness metals being welded together

Where do you get this? You are one of the reasons I quit posting here because of the nonsense you post. Sad part is people probably listen to you. 140-180 amps are you serious? Please

[motolife313]

Testing myself

[Welder Dave]

Fair point. I do think a good welder could do it in one go in one direction though.

On something critical a good welder would know not to leave a crater at the end. It's kind of welding 101, eliminate as much as possible potential for cracks to propagate. Take it as info to remember for the next time instead of questioning it.

[husq2100]

On something critical a good welder would know not to leave a crater at the end. It's kind of welding 101, eliminate as much as possible potential for cracks to propagate. Take it as info to remember for the next time instead of questioning it.

Can you define crater? To me that is a concave hole , it’s lowest point is lower than the weld profile??

My pics may not be very clear, but on the finished product they are not. I would call it a “mound” for lack of better term. The “mound” is higher than the weld profile and even the one that has the tiny pin hole has the bottom of hole higher than weld profile.

Saying a good welder could do it in one pass in one direction was not question your imput mate, actually agreeing with the crater part. I’ve seen plenty of high end motor sport TIG welding and they don’t end in a crater where they stop. They are simply (MUCH!) better than me.

[husq2100]

Where do you get this? You are one of the reasons I quit posting here because of the nonsense you post. Sad part is people probably listen to you. 140-180 amps are you serious? Please

There are a few reasons people post miss information on forums....

I did balk at it with my limited experience but just put it down to him probably having a peddle. Given the tube was only 2.8mm thick, that would put it at 110 amps using the 1 amp per thou rule.

[motolife313]

140 is very doable. 180 probably a bit fast for the slow guys

[motolife313]

How bout the Lap joint done at 160 and 180? .125 thick

https://weldingweb.com/vbb/showthrea...t-Sorry-Jodie-)

[Welder Dave]

Can you define crater? To me that is a concave hole , it’s lowest point is lower than the weld profile??

My pics may not be very clear, but on the finished product they are not. I would call it a “mound” for lack of better term. The “mound” is higher than the weld profile and even the one that has the tiny pin hole has the bottom of hole higher than weld profile.

Saying a good welder could do it in one pass in one direction was not question your imput mate, actually agreeing with the crater part. I’ve seen plenty of high end motor sport TIG welding and they don’t end in a crater where they stop. They are simply (MUCH!) better than me.

Anytime you stop a weld you have a crater. In motorsport welding it is usually tubing with a continuous weld all the way around. There is no end per say.

[husq2100]

Anytime you stop a weld you have a crater. In motorsport welding it is usually tubing with a continuous weld all the way around. There is no end per say.

Plenty of welds on parts that are not tube or continuous around. So how does one stop a weld that is not continuous?

[Welder Dave]

Weld in from both ends and make sure the final crater in the middle is fully filled.

[husq2100]

.... “make sure the final crater in the middle is fully filled”.

If filling the crater is the critical part (which to me it is) I thought that was done at every end ( unless start up from that point is going to take place)with technique by the use of filler and back trailing the arc a little?

[Welder Dave]

Generally back stepping at the end is sufficient but on something critical, welding from each end inward is the best way to eliminate potential crater cracks.

[shovelon]

Underfilled terminations leave a stress riser at the end of the weld that can crack prematurely or even crack when the puddle chills. Nothing wrong with returning to the crater and filling them some more later. Underfilled weld starts are just as much as a problem as underfilled terminations. Craters are by definition a shallow termination with possibly a divot in the center where the crater crack can develop.

When starting a weld, get a uniform puddle and pack that start with filler for an adequate throat. 2 to 3 dips of your rod can pack it thick then move forward. Upon termination reduce your amps and again pack that end with filler as not to leave a underfill or crater. And upon lifting your hood you see it underfilled go back and fill it some more.

Another thing, don't drip you filler into the puddle. Cram that rod in and plump up the bead for throat thickness and strength, them jam forward. As long as your bead spacing is not longer than 40% there should not be shallow spots between the beads to create stress risers. Cram and jam. Speed is your friend.

[Munkul]

It's very simple IMO If you can't get the required weld throat/profile with a single pass without compromising on other things like root quality, heat control etc, then run it in two passes.

You already understand root penetration and weld size etc, so to me, looks like 2 passes will make a better job than a single.

TIG is really limited by how much weld metal you can stuff in without affecting travel speed and burn-through with high amps. That's why you'll see a lot of concave TIG fillet welds. It's not a problem, it's just something you have to take into account if you need a certain throat size.

[motolife313]

That’s where pumping the pedal comes in, slow the roll of the heat by pumping the pedal and you can pump up the throat with with rod.

[_Dom]

He doesn't have a pedal.

[motolife313]

He doesn't have a pedal.

I know. He’s stated it many times in the thread

[Munkul]

I don't use a pedal, i use a button with a sequencer, and that job to me looks like around 120-130 amps tops, coupled with 2-3 seconds downslope to 20% before arc termination. Maybe 140 amps if you're feeling frisky.

I can't see no crater in that pic, just a rather large end puddle... longer downslope might help... either way it doesn't look terrible.

[Joker11]

[QUOTE=shovelon;Cram and jam. Speed is your friend.[/QUOTE]

My experience tells me this is frowned upon by many women.

[shovelon]

My experience tells me this is frowned upon by many women.

Many, not all.

[Joker11]

Touche’