what are the limitations of "lift tig facility" xti160/pro arc 180/175SE

[MoreWellie]

These all come with "lift tig facility" as there are no built in gas controls/down slope/post gas etc. What does this mean for the welding process

I understand you can get a tig torch with gas control but how do you stop the weld and still keep gas coverage for the necessary 5+ seconds?

Is it realistic to expect to weld thin sheet with this sort of welder?

If you already have mig are there any advantages with this sort of tig on thin sheet?

 

[Tom Orrow L]

You can achieve very good TIG welds with a simple lift TIG machine, jody from welding tips and tricks shows a lot of brilliant techniques for working them real nice.

I'm no expert TIG welder myself but i've done a fair bit of lift TIG with my old set and the way I would finish the weld was simply to "circle out" which was kind of like moving my torch in a small circular motion whilst slowly creeping away from the work piece, whether thats the best way to do it I couldn't tell you. Richards the man to ask, the forums very own TIG god.

Thin sheet can be welded quite easily with lift TIG, 1MM/2MM easy.

I believe i'm correct in saying that one of advantages of TIG on thin sheet are that it puts less heat into the plate, making distortion a little easier to control. Someone please correct me if i'm talking out my backside.

*I WAS TALKING OUT MY BACKSIDE IT APPEARS *

 

[Jim Davey]

Right, you have pretty much figured out the major drawback of TIG LIFT function, it welds just great but the issues come at the end of the weld, you have to snap the torch away from the work piece to break the arc then whip it straight back to protect the hot metal from oxidising. This is problematic and can ruin the finish on an otherwise good quality weld seam. Some machines like certain models in the Fronius Transpocket range have an arc sensing circuit that sees the voltage change when you lift the torch above a certain height and slope out automatically but they are more money than cheaper makes of TIG kit with slope, HF and pulse so no benefit there really.
If you want to TIG, and you haven't already shelled out fort a stick set, keep saving for a TIG.

As for sheet metal, its difficult to manage the distortion on thin sheet welded with TIG as the process is much slower allowing heat to build up for longer, it also requires a lot more skill and greater accuracy of fit up (MIG will easily fill a gap with little in the way of technique, but TIG won't, it melts away edges not touching each other and requires deft handling of torch angle and filler rod to overcome it's natural tendency to melt away from the arc. MIG is what I'd use for sheetmetal repairs to vehicle bodywork, but if I had a 1.5-2mm mild steel sump to modify for example, I'd use TIG with a 1.2mm filler and be happy I'd get a good result, BUT I'd be conscious of the fact all my fit up prior to welding would have to be spot on.

 

[Kent]

Tig is worse on distortion as it runs slowly along
Once over we only had scratch - still did good work but once you give everyone hf start skills and practice are soon lost
I don't do much at all now and had to pretty much re- teach myself after a long break from welding and fabrication
If your welding over the pass just come out to the side to maintain coverage
If your not come onto a copper plate as a " run off"
Alternatively just snap sideways
I like to feed extra filler at the end it cools the pool some and helps prevent the pin hole ( someone might tell me that's bad but it's what I do)

The advantages on thin sheet if we are talking ms is a neater smaller weld than mig ( better looking) over mig

My opinion if you don't need a pretty little unground bead is mig it!

 

[BrokenBiker]

lift arc on my first xti160 saved me a few times when my mig was dead and i had to get something thin welded up...with practice you can break the arc and still get coverage

 

[Jim Davey]

I'm not saying you can't doo good work on a lift tig, but its a lot easier to get good results on what is already a high skill process with the addition of a few useful features you only get on a dedicated stick set.

 

[BrokenBiker]

I'm not saying you can't doo good work on a lift tig, but its a lot easier to get good results on what is already a high skill process with the addition of a few useful features you only get on a dedicated stick set.

totally agree, every tig job ive done would have been much easier with HF and a bit of downslope

 

[Mr Fro]

I've been practicing with my lift/scratch TIG on my CWS welder. I put a pneumatic foot switch in line with the gas supply so it's not flowing while I'm not welding. Still, it's a bit of a art to lift off at the end of a run and avoid blowing through or cratering but maintaining adequate gas coverage.

I think having a proper set up with all the controls would be waaay easier than all this scratch stuff.

 

[Freddy0309]

I can't remember if it was lift or scratch start but didn't jody from welding tips and tricks showed a way to make a foot pedal to cut the current?

 

[Jim Davey]

He did do that. Doesn't really matter if it was scratch or lift, the pedal is just to break the arc at the end of the run. However the effort that went into making the pedal could've been better spent earning the money to just buy a TIG, I think he said himself that it was more done as an experiment because he had time on his hands and wanted to see if it would work. Personally a big pedal with exposed copper conductors at full welding current potential next to an earthed bench etc. is a recipe for an accident.

 

[henry Kadzielski]

Good morning gentelmen
I now have an essetti thor 200hf with down slope and have had for some time. Previously lift arc or scratch start, which ever terminology you prefer. The HF start with down slope is the 'bees nees'. I myself don't use the down slope as seldom weld realy thin material, nothing below about 1.6mm. At the end of a run just quickly pull the torch along the welded seam to finish. Most of my work is pipe joints so all finish at the begining. It is much easier with the HF start, however no biggi to return to lift arc, just would take some adjustment.

 

[MoreWellie]

Thanks everyone

The more I read about it the more I thought that my need for tig was coming out of tool envy. Now I have it confirmed! not sure whether to fell happy or sad

 

[Richard.]

Are we talking lift or scratch here because there very different. You don't need to break the arc on lift arc Tig. That's scratch start. LIft is simply the same as hf start but you need to start in contact. Release the switch and it will slope and post if the unit allows.
Scratch is a permanent live torch where flicking off and breaking the arc is needed and in inexperienced hands can be a poor tool. A good user can avoid contamination and post gas issues. I learned on this process. Tig is a very usable forgiving process in the right mans hands. Distortion is more of a problem but can be controlled with travel current and on nice machines pulsing.
Jim I don't see bridging a problem with Tig personally. I try to avoid bad fit up with any process but Tig will bridge seriously big gaps but again devotes more skill from the user.

 

[BrokenBiker]

Are we talking lift or scratch here because there very different. You don't need to break the arc on lift arc Tig. That's scratch start. LIft is simply the same as hf start but you need to start in contact. Release the switch and it will slope and post if the unit allows.
Scratch is a permanent live torch where flicking off and breaking the arc is needed and in inexperienced hands can be a poor tool. A good user can avoid contamination and post gas issues. I learned on this process. Tig is a very usable forgiving process in the right mans hands. Distortion is more of a problem but can be controlled with travel current and on nice machines pulsing.
Jim I don't see bridging a problem with Tig personally. I try to avoid bad fit up with any process but Tig will bridge seriously big gaps but again devotes more skill from the user.

my lift arc doesnt have any sort of switch at all and i have to whip out of the arc to end it...and yes mine is called lift arc, i dont need to scratch to start the arc, just touch the work piece and then lift off

 

[Richard.]

my lift arc doesnt have any sort of switch at all and i have to whip out of the arc to end it...and yes mine is called lift arc, i dont need to scratch to start the arc, just touch the work piece and then lift off

Is the torch permanently live bb.
What ever they may call it I would say that's scratch.

 

[Kent]

I am surprised by what you said there about lift. This is not entirely correct most mma with tig inverters have lift and the torch doesn't have a switch and is as you say permanent live as in scratch.
When I refer to scratch I mean just that and any DC mma set
That buddy I have has always needed scratch but strangely if you knock it onto tig by accident it starts on the lift of a 2.5 7018
The Lorch Micor stick has a cracking lift ignition however but again manual gas valve and no slope and no switch

 

[Jim Davey]

Lift arc and scratch start are different ways of initiating the arc, lift is kinder to the tungsten. But the both however end the arc the same way, snap out, they and get the gas back onto the job as fast as possible.

Gap bridging is easy if your skill level is high enough, don't forget though this is greatly helped by heat control with a pedal, you won't get that option on a stick set with tig torch added to it, therefore it might be a bridge to far (no pun intended) for the beginner.

 

[Kent]

Is the torch permanently live bb.
What ever they may call it I would say that's scratch.

I think that might be a case of never having suffered what we used to have real scratch start

 

[BrokenBiker]

yes the torch is permanently live, but there is no scratching involved...ive used scratch start sets and the one i used was a mare to get started, was like striking a match, the xti is just a gentle touch onto the work and as soon as you lift off it starts the arc. i think it uses the anti stick function from the MMA side to do it, and i also think it incorporates the hot start as the arc flares up for the first second or so, although that could partly be me long arcing it after starting the arc

 

[Richard.]

Ah ok. I've used a lot of scratch start units where you flick off the job or filler to strike up but when ever ive used lift arc (rarely) it's still been contact ignition but on a Tig unit where the torch isn't live. I've not used lift arc on a permanent live before so perhaps that's my confusion.
Again though live lift or scratch in capable hands is are very usable processes. Scratch devotes practice with starting to avoid sticking where as lift is a more controlled start. I used to strike up a lot off the filler rod when using scratch