Trouble tig tacking steel

[Noods]

Hi All..

I'm trying to tig weld DC with my esab 160 a couple of 2mm thick steel brackets to 2mm square hollow section..

I'm still not really sure on quite how I should tack them on..

I've tried turning up the amps and giving it a short blast.. I've also seen people tacking with filler rod... I seem to be failing to get a tack at all..

Advice would be really appreciated please..

Thank you ..

 

[hotrodder]

There'll be some vids covering tacking in the TIG tutorial at the top of the page. Without pics don't really know where you're going wrong but as excessive arc length is usually involved... http://www.mig-welding.co.uk/forum/threads/arc-length.7862/ If the pieces are touching then filler is optional for tacks, if there's a gap then obviously you need to add some wire or the edges will just melt back

 

[whm_fab]

as hotrodder said, fit-up and arc length are key - even a 1mm gap will require filler 99% of the time.

Also, when tacking, make sure you have a freshly ground pristine tungsten, this is very important

 

[langy]

As Pete said close arc length, perfect fit and sharp tungsten, any gaps and filler will be needed.

 

[norlander]

I seem to be failing to get a tack at all.. try playing with different cup sizes and use a gas lens and extend the tungsten a bit-you may find you can rest the cup on the job and rock it over and get the puddle going -google walking the cup.
You can also lay the filler in and walk the arc onto it in some circumstances try a google on laywire technique-theres a few dodges you can use that might work for you.

 

[Wallace]

I had problems tacking up when I first started Tig, after a few tips from the likes of Hotrodder and Langy etc I finally nailed it and as if by magic they started to appear. The arc length was my problem, not deep enough into the root and a lack of power.

 

[Richard.]

Clamp both peaches together to give you the use of both hands and help with the fit up (if it's possible to clamp)

 

[Richard.]

Peaces I meant.

 

[Paul.]

Peaces I meant.

Or even "pieces"

 

[Richard.]

Or even "pieces"

That's the one. Got there in the end .

 

[rohart]

Sounds to me he isn't getting a puddle. You need to melt material on both pieces, you need to be able to see the puddles, and thee two puddles must mix. If the pieces were originally touching, there's a good chance the two puddles can touch and coalesce before they melt back.

Once the two puddles mix, cut the current and that's a tack.

If the puddles melt back, creating a space between them, add filler to one puddle until it mixes with the other. That's your tack.

If the puddles melt back so the arc can only get at one piece, add filler till the puddle wets the other piece, wait till a puddle forms on the second piece and the puddles mix. That's your tack.

If one piece is dirty, it will stop the puddle from the other piece from wetting it. You'll get lots of spluttering, and you won't be able to see what's going on.

If both pieces are touching and really clean, you're using sufficient amps, your electrode is clean and the gas preflowed, it's a piece of cake.

 

[overload]

Set it up so it behaves like a on/off switch. No up slope, no pulse, high current only and a quick down slope (1 sec max).
Use a dab of filler when you see a puddle appear and then turn the torch off. Job done.