[rahtreelimbs]

If you are using a scratch start tig setup......no pedal.....no downslope. What is the proper way to end out a weld and avoid craters and such.

[weldin mike 27]

Speed up at the end of your bead until the pool is very narrow. Snap out and then get the torch back over the puddle quickly to give a little gas

[Mike Westbrook]

You can always end on a tack weld

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[cj737]

I also lay the torch for a more cure angle to push the puddle to the end, adding a bit of filler to help avoid a crater. All depends upon the material and position.

[Poland308]

Speed up at the end of your bead until the pool is very narrow. Snap out and then get the torch back over the puddle quickly to give a little gas

90 percent of everything I do is scratch start. Like this method, or if it’s real critical that you don’t get any arc marks you can always snap out along your filler wire. Use it like a ground rod.

[tweake]

or use a run off tab.

edit: i should add....... whats your best way to snap out ?

[MinnesotaDave]

If not using the good advice already given, another way is all about timing.

At the end, quickly add a few extra dabs of rod and then snap out immediately (snap back to shield the weld).

It's how I usually do it. It's how I "button off" - not sure why I call it that

[tweake]

........... and then snap out immediately (snap back to shield the weld)...........

thats something i found difficult and produced a lot of swearing. mainly because the arc re-established.
to stop it the arc restarting i had to hold way off, way out of range that the gas would do anything.

[Artie F. Emm]

Reluctant to join the thread because i'm so far out of my depth. Would it be practical to add a normally closed foot switch to the ground cable? Stomp the switch to interrupt the ground, arc stops but gas keeps flowing.

[Poland308]

(thats something i found difficult and produced a lot of swearing. mainly because the arc re-established.
to stop it the arc restarting i had to hold way off, way out of range that the gas would do anything.)

Use lift arc and turn off your high frequency.

[cj737]

Reluctant to join the thread because i'm so far out of my depth. Would it be practical to add a normally closed foot switch to the ground cable? Stomp the switch to interrupt the ground, arc stops but gas keeps flowing.

Some lift arc machines still rely on a foot pedal as an option to modulate the amperage. Lift Arc or Scratch Start is purely for machines that don't have HF start, or when you don't want to rely on HF because of out-of-postion welding. (Think moving around a large structure where you are tacking or welding, and you don't want to drag a foot pedal with you).

You could always go with a 2T or 4T torch switch. But as Poland said, if snapping out and returning to shield causes the arc to reinitiate, then you're still active on HF. LA/SS machines often have a programmed post-flow to cool the tungsten. So returning to shield the weld should not cause an arc start.

[Artie F. Emm]

^^^ Thanks for the explanation. I see a lot depends on the individual equipment setup: I had in mind a Thunderbolt or Tombstone with a basic torch.

[tweake]

(thats something i found difficult and produced a lot of swearing. mainly because the arc re-established.
to stop it the arc restarting i had to hold way off, way out of range that the gas would do anything.)

Use lift arc and turn off your high frequency.

no HF on that machine. DC tig only, no pedal, no switch, no gas solenoid. its multi process so tig is a really basic add on.
like adding tig to an arc welder. live all the time. common sort of setup.

i found rotating the torch was the best way for me to snap off. but rotate it back it could restart, even if your an inch off the work.
ended up simply rotate and lift torch up and away, and forget about trying to cover with gas.
in the end i was so annoyed with it i got another welder with HF, pedal etc. which was good as i ended up doing aluminum.

once that gas is pulled off the work, oxides form instantly. so i fail to see the point of snapping off then putting gas back on, damage has been done. that really shows up on stainless.
this is where a run off tab is probably better. then it doesn't matter how bad the end of the weld is as its thrown away.

i think jody has a few videos on this.

[cj737]

no HF on that machine. DC tig only, no pedal, no switch, no gas solenoid. its multi process so tig is a really basic add on.
like adding tig to an arc welder. live all the time. common sort of setup.

in the end i was so annoyed with it i got another welder with HF, pedal etc. which was good as i ended up doing aluminum.

once that gas is pulled off the work, oxides form instantly. so i fail to see the point of snapping off then putting gas back on, damage has been done. that really shows up on stainless.
this is where a run off tab is probably better. then it doesn't matter how bad the end of the weld is as its thrown away.

i think jody has a few videos on this.

If it’s DC TIG only, how did you do ally with it?
The benefit of shielding gas on ally after the arc stops is to help cool the ally slowly, avoiding heat cracks. Also somewhat true on steel as the shielding still helps prevent oxides from entering the weld while it cools. Yep, mandatory for stainless, but still a great idea for all materials

[tweake]

If it’s DC TIG only, how did you do ally with it?

i got another welder (acdc tig) and used that for aluminum.

my other welder is a multi with DC only lift tig.

[cj737]

If it’s DC TIG only, how did you do ally with it?

i got another welder (acdc tig) and used that for aluminum.

my other welder is a multi with DC only lift tig.

I suspected as much; the old "bait and switch" on us! Damn tricky Kiwis Thought you had somehow developed a method to DC TIG ally without Helium and were holding the secret close to your vest.

[weldin mike 27]

Jody has a video of making a knife switch on the stinger cable so you can cut the current but keep the gas shielding

[cj737]

Jody has a video of making a knife switch on the stinger cable so you can cut the current but keep the gas shielding

I’ve just run a gas valved torch that is manually opened and closed as needed. Allows pre- and post-flow control as I deem necessary. Can be a bugger to remember to open it though.

[wronghand]

Ya one final big dab and snap out QUICK. It can be done fast enough to maintain gas coverage. Industry standard for field welding AS pipe is still a scratch start rig on an engine drive welder. I do it all the time and manage to NOT oxidize the end of a weld. It takes a lot of practice tho...

[Louie1961]

In addition to the knife switch video, Jody did this video because of a question from me (those are my pads of beads he shows in the video!!!)...use a copper spoon

https://www.youtube.com/watch?v=28NRNYACv9I