Pulse Tig welding

Noticed various articles on this newer system which seems to be a lot better for dealing with thinner materials

Anyone got experience using it?

There also seems to be a cold weld system doing the rounds just now, mainly just kids mucking about

Edited By Ady1 on 05/11/2021 00:36:44

My 10+ year old TIG welder has pulse capability. Pulse works well, easier than trying to modulate with the foot pedal. Not sure why cold welding is so named as it clearly isn't a cold process. It's just a series of tack welds, essentially an extreme example of pulse welding.

Andrew

I wonder what the weld penetration is like ?

Would this cold weld method be approved by a boiler inspector.

I have always (recently) wondered how firebox stays are fixed on a welded copper boiler. The outside ends of the stay would be OK, but how do you seal the inside ends?

My TIG welder also has the pulse capability. As Andrew pointed out this is NOT a cold process, rather it is a way to control heat input.

Especially on thinner materials, with a continuous arc not only melts the metal to form the weld bead, but also can add so much heat into the surrounding metal that the entire piece burns through before one has successfully welded it.

The pulse process allows the operator to define the on-off welding current time such that only the required amount of heat is used. Usually, this just means a more controlled welded seam, without dumping unneeded additional heat into the surrounding area. And, yes, the process can be so slowed down to the point that it is, in effect, a sequence of 'tacks'.

Another benefit of the pulse process that I might mention is that used at higher frequencies the pulsating arc agitates the weld pool and encourages a better blending together of two edges of butted metal.

Of course the pulse process is only another 'tool' and one usually has to practice a bit to find the correct pulse settings (frequency, on-time, base current). Best to do this on some scrap before you tackle the actual work piece.

One other use that I have found for the pulse process is smoothing out the edges of extremely thin cut metal (such as stainless steel). For this I set the pulses at a somewhat slow rate (something like 2 to 5 pulses per second) and the welding amperage only sufficient to 'bead' the edge but not cause it to melt back. In this way, I can run the pulsed arc along the edge of the metal, the series of little beads forming a smooth, rounded off edge.

The youtube video that followed Ady's link explains and puts 'cold welding' into perspective better I think. What 'Mr Weld' shows fits with Andrew's comment and Speedy's concern with lack of penetration.

Not magic. I'd imagine it's useful for tack-welding and joining thin materials, but risky on anything heavier or where penetration matters. If I had one I'd play with it, and I'm sure it's a good thing in the right circumstances. But it does look likely to be misunderstood or abused as a way of faking good looking, but weak, welds.

Dave

I would suggest the video link below as a good introduction to possible uses of the pulse feature.

Testing TIG Welding Techniques

I've been using a device called a PUK welder for some time now. It's similar to the Orion pulse welder shown in Ady1's last link. It's specifically designed for jewellery and dental work, but useful for all sorts of small things, such as tack welding small items prior to soldering. It has a 10x self darkening binocular microscope and items to be welded are hand held right next to the weld point. I typically use it for welding new tips to claws without removing the stones.

I take exception to Ady1's statement about kids mucking about, it requires considerable practise, experience, and skill to use properly.