First go at TIG

[Pete.]

More practicing this weekend. These are the best of 'em. Square plate is 2.5mm sheet with runs of 4043 (shiny) and 5356 (dull). Larger piece at the back is 2mm and the little'un is 1mm thick. near the edge some welds got a bit too hot and I couldn't keep up.

I was having trouble striking an arc with the 1mm. Had the set turned down too low but to turn it up enough to get a decent arc meant I had to move fast or gain too much heat. My next set is definitely having a pedal.

 

[Richard.]

Looks to me like you have this well mastered. Have you had any practice with fillet joints. This looks like your next step and by your progress so far I would say you will soon nail that too.

 

[Richard.]

To be real critical you have small craters on the ends of your runs. Set a down slope on the machine and a 5-7 sec gas post. When you come off the trigger and the current starts to faze out the metal will still be fluent so give it a final dab just before the arc goes out and keep the torch held over the weld end until the post gas has completely stopped.

 

[Pete.]

Thanks Richard.
I have the post flow set to 8 seconds but I have no slope control so I've been experimenting with trying to put a dab of filler just as I let off the arc to allow for the shrinkage. Most often it just sticks the rod in the weld pool though.

 

[mr migwire]

bleeding norra mate thats looking good for only having the tig plant a short while,

 

[hotrodder]

Thanks Richard.
I have the post flow set to 8 seconds but I have no slope control so I've been experimenting with trying to put a dab of filler just as I let off the arc to allow for the shrinkage. Most often it just sticks the rod in the weld pool though.

I know we covered a hell of a lot in a couple of hours but do you remember me pointing out that i briefly restruck the arc to sort the crater? Add an extra dab of wire just before letting off the button and then if (when) a crater forms briefly restrike and it should be levelled/filled.

In the real world when not running beads on offcuts (time to quit that and concentrate on butts, outside corners and fillets) craters are only usually an issue on final tie ins which gives a couple of other options... with scratch TIG on pipe for example instead of stopping at the final tie in you can keep going but much faster so the weldpool freezes and then break the arc. Another way is to circle the torch as you break the arc i.e. keep it moving as the weldpool freezes

 

[Pete.]

I picked up a stash of practice material today from my mate's guillotine scrap bin, so armed with a pile of stainless and ally tokens I'm going to start practicing my butts and fillets. With the few I've done already I've had trouble tacking the edges together without them burning back. On ally it seems to happen very easily so I get in with a dab of filler but the rod burns back and I end up with an unsightly dollop of filler. Looking for some advice on how to avoid this.

By the way someone is selling the exact same welder I have as a non-working unit. I'd buy it for spares but it's up in Widnes and I'm in Kent. It's at a very low price right now and I guess that (like me) few people realise the 3 phase units will run quite happily on 240V domestic supply. 321558057413 if it interests you.

 

[Paul.]

With the few I've done already I've had trouble tacking the edges together without them burning back. On ally it seems to happen very easily so I get in with a dab of filler but the rod burns back and I end up with an unsightly dollop of filler. Looking for some advice on how to avoid this.

Put the end of the filler rod in the joint before you arc up then a quick blast to join all 3 pieces together.

 

[Pete.]

Cheers Paul, I'll have a crack at it and report back later.

 

[Pete.]

Practicing with joints on thin stainless. Outside corner, not too bad but I lost the fusion a couple of times.

Now a fillet. The mess in the middle is where I started, but had to wind up the power three times to get going.

And an inside corner. Seemed damn near impossible, I switched to a smaller ceramic and stuck the tip out and I still couldn't see too well.

 

[Pete.]

Then some more fillets and a little butt weld to finish. I'm amazed at how much the material warps and lifts off the bench. How do you combat that?

 

[Jan]

At first look I'd say you're progressing by leaps and bounds. I wish I were doing as well. Mind you: I've got a lot of other, more urgent projects to clear out of the way.

As for warping; that's a simple product of heat going into the metal in a small area at a time. Nothing can be done about that in most circumstances as the heat can rarely be taken away by a heat sink fast enough to make much difference. Once you take that into account it's just a matter of making more tacks closer together so that there's less room for the metals to move away from each other before you blaze away with a long run. On MIG welding you usually just run a short bead, repeat a few inches away and continue until you get to the end of the joint. Then you 'go back' and start to fill in the unwelded portions. The resulting weld may not be as pretty as a single continuous bead, but at least it should be strong! On thin materials such as car bodywork this can look like a series of tacks that join up (after a fashion) and usually require a fair bit of grinding back to be smooth enough for overpainting. I doubt that TIG would look any nicer.

 

[Pete.]

Really struggling with fillets on thin ally. Butts I can do a pretty good job on 2mm and fairly passable on 1.2mm but fillets are another matter. Have trouble getting them going then if I get close enough to get the pool going I touch down when I add filler or if I pull away the arc gets too long and it all goes horrible. Turn the amps up and it burns back. On 2mm it's a lot better but I still struggle to get it going a bit.

Going to have another crack tonight on 2mm with a 2.4 tungsten instead of the 1.6 on 2mm.

 

[Richard.]

your machine does not have adjustable freq Hz, fillet welding Ali tig is hard at the best of times for people starting out but with fixed Hz that makes it harder still as tightening up that arc with 100-120 Hz would make it more bearable on the thin stuff. I think it's time to put your hand in your pocket before the lack of functions on your machine prevent you progressing further. I get the feeling your enjoying it so it will be a worth while investment.

 

[Windy Miller]

your machine does not have adjustable freq Hz, fillet welding Ali tig is hard at the best of times for people starting out but with fixed Hz that makes it harder still as tightening up that arc with 100-120 Hz would make it more bearable on the thin stuff. I think it's time to put your hand in your pocket before the lack of functions on your machine prevent you progressing further. I get the feeling your enjoying it so it will be a worth while investment.

If you want Pete, you can have a crack at it with my machine. I've been meaning to get it sorted with some new ceramics & stuff for ages - it would give the kick up the @rse that I need to get it done! Might even get myself a nice sexy little torch like yours!

 

[Pete.]

your machine does not have adjustable freq Hz, fillet welding Ali tig is hard at the best of times for people starting out but with fixed Hz that makes it harder still as tightening up that arc with 100-120 Hz would make it more bearable on the thin stuff. I think it's time to put your hand in your pocket before the lack of functions on your machine prevent you progressing further. I get the feeling your enjoying it so it will be a worth while investment.

So what I am experiencing is normal? That's good to hear and gives me hope. I'll get cracking with the 2mm practice and leave the 1.2mm alone. Is there any other way of manipulating the arc via grind or stickout etc? Maybe use a heavier tungsten and grind it to a point?

If you want Pete, you can have a crack at it with my machine. I've been meaning to get it sorted with some new ceramics & stuff for ages - it would give the kick up the @rse that I need to get it done! Might even get myself a nice sexy little torch like yours!

That's very generous mate. I might take you up on that and buy whatever bits you need to get it going. It would be nice to see what I'm missing by way of controls.

 

[Paul.]

You can experiment a bit with tip geometry, using a 2.4 and grinding it in 2 stages can be useful, the thicker electrode carries the current and dissipates the heat, and the smaller tip concentrates the arc, when it balls it should look like the lower picture, don't forget to keep the grinding marks in line with the electrode,

 

[Wallace]

That's a cracking bit of info, I can think of a small job I struggled with where that would that probably would have been a big help.

 

[Richard.]

So what I am experiencing is normal? That's good to hear and gives me hope. I'll get cracking with the 2mm practice and leave the 1.2mm alone. Is there any other way of manipulating the arc via grind or stickout etc? Maybe use a heavier tungsten and grind it to a point?



That's very generous mate. I might take you up on that and buy whatever bits you need to get it going. It would be nice to see what I'm missing by way of controls.

Yes very normal. It's not impossible to produce acceptable fillet joints with fixed Hz and with the advice given on the geometry of the tungsten from Paul above this will help further as tungsten design is a big player on the width of the arc produced. However like I said your loving your tig welding and your not going to understand fully how AC freq and balance really do effect the weld produce until you have those variables on your unit. You will love it even more and have a lot more questions to ask once you start using them. Oh most important if you do buy a unit with those functions I would suggest you buy a pedal too as creating a puddle and end craters will not be a problem again for you.

 

[Pete.]

It'll be on my list but probably not until after Christmas.You're right I am enjoying the learning of a new skill, it's something I've wanted to do for some time.

Some 2mm ally fillets. Gotta get some more material as I only has a couple of sheets of 2mm where I had a bunch of 1.2.