Some TIG problems

[PSweeney]

Been having some issues with my TIG welding, hoping you guys can give me some pointers ?

1, I'm struggling to find the right amps to use on fillet welds. If I lower the amps, I struggle to get the puddle started down in the root (although a dab of rod into the arc seems to help start it), if I raise the amps I end up with the puddle formign too quicking and undercutting on the vertical side. If I angle the arc to the horizontal piece, I loose the puddle in the corner of the joint and the bead washes out onto the flat. Welding on 3mm mild between 80-90 amps, starting high and reducing as the piece heats.

2, Been welding 20mm OD tube to flat plate. The radius around the tube is too tight for me to do in one continuous weld so I'm doing it in maybe 4 small beads. The problem I'm having is at the end of each bead, no matter if I slope down / post flow for longer etc or pull the arc back along the bead, I'm getting a small raised peak. Why is this and how can I avoid it ?

3, Gas coverage, I'm using a No6 cup for most welds (mostly 3mm fillets) which allows me to get down into the root with the tungsten but not stick the tungsten out too far. I'd like to use a bigger cup as I think I'm running a little hot (welds are mostly grey) and the tungsten point (1.2mm thoriated) is dulling very quickly, requiring re-sharpening maybe after 3-5 welds (but not due to dipping just dulled). How far out can I run the tungsten with a No10 cup for instance ?

Thanks

Phil

 

[wheresmejumper]

point 1 could be due to too long of an arc length

the raised peak is poor gas shielding,possibly from wrong torch angle if its only happening on tube to flat

uncleaned mild steel can spit back at the tungsten,contaminating it more and more as you weld.are you grinding the mill scale off first?

 

[Wendelspanswick]

A no.10 cup would be overkill, a 7 or 8 (=1/2") would be better but I imagine its just technique as small diameter tube to flat will take a while to master.
Try angling the torch at 90 deg into the fillet as you finish, its easy with tube to crank the torch back too far as you go around drawing in air from behind the torch.

 

[PSweeney]

point 1 could be due to too long of an arc length

the raised peak is poor gas shielding,possibly from wrong torch angle if its only happening on tube to flat

uncleaned mild steel can spit back at the tungsten,contaminating it more and more as you weld.are you grinding the mill scale off first?

thanks for replying, really trying to keep as short arc length as possible. I guess the raised peak is associated to torch angle as I struggle to see the puddle having moved round the tube, maybe I'm leaning it back to see.

The steel is cleaned to bright with 36 grit roloc disc, they only just take the mill scale off, maybe I need to grind it back a bit more

 

[PSweeney]

A no.10 cup would be overkill, a 7 or 8 (=1/2") would be better but I imagine its just technique as small diameter tube to flat will take a while to master.
Try angling the torch at 90 deg into the fillet as you finish, its easy with tube to crank the torch back too far as you go around drawing in air from behind the torch.

thanks yeah the small OD tube is a killer, smooth movements on such a tight radius and on a fillet is harder than imagined

I'll straighten up the torch at the end, I think I'm increasing my angle to see the weld and not getting gas coverage and as you say maybe drawing in air from behind the torch.

 

[langy]

Been having some issues with my TIG welding, hoping you guys can give me some pointers ?

1, I'm struggling to find the right amps to use on fillet welds. If I lower the amps, I struggle to get the puddle started down in the root (although a dab of rod into the arc seems to help start it), if I raise the amps I end up with the puddle formign too quicking and undercutting on the vertical side. If I angle the arc to the horizontal piece, I loose the puddle in the corner of the joint and the bead washes out onto the flat. Welding on 3mm mild between 80-90 amps, starting high and reducing as the piece heats.

2, Been welding 20mm OD tube to flat plate. The radius around the tube is too tight for me to do in one continuous weld so I'm doing it in maybe 4 small beads. The problem I'm having is at the end of each bead, no matter if I slope down / post flow for longer etc or pull the arc back along the bead, I'm getting a small raised peak. Why is this and how can I avoid it ?

3, Gas coverage, I'm using a No6 cup for most welds (mostly 3mm fillets) which allows me to get down into the root with the tungsten but not stick the tungsten out too far. I'd like to use a bigger cup as I think I'm running a little hot (welds are mostly grey) and the tungsten point (1.2mm thoriated) is dulling very quickly, requiring re-sharpening maybe after 3-5 welds (but not due to dipping just dulled). How far out can I run the tungsten with a No10 cup for instance ?

Thanks

Phil

I've run the tungsten out 1/2" with a gas lens sometimes more, no problems

 

[chrismac]

are you running on a bit on the slope down to let the bead shink/taper down in size, then start 1/2" an inch on the good bead overlapping the stop. Mild steel the motto I was told is plenty of heat and plenty of wire, keep the wire in the pool all the time, you have to move fairly quick.

If your tungsten is furring up needing a sharpen you could have gas leakage, the colour does not matter, it goes blue with the heat, in my experience.

Chris