Hi there, New to welding. Constructive criticism wanted

[McG]

Hi there,

I have just joined up here and thought i'd start by saying thanks for all the useful information and tips on here. I have found it all truly invaluable. I haven't done a great deal of welding in my time nor had any formal tuition. I started playing around with TIG around a year ago and picked up what i know from various websites or hints from friends.

I have included a few pictures below of some of the welding I have done recently, some of which I think is good (for me), and some not so good. I'd like if you guys had a look and told me what you think I may be doing wrong or anything I could do to better my skills.

The machine I have been using is a Cebora, and the material in the pictures is BS4T45 and varies from 1mm to 3mm. Using between 40 and 80 amps with a 2.4mm thoriated red tungsten electrode and A31 rods.

Also i'm hoping to try my hand at practicing some aluminium welding soon.

Thanks
Dave

(Edit - apologies for posting in the wrong section, i have just spotted that this is specifically for learning MIG)

 

[madkayaker]

more filler needed and try to get the fit up a bit better on the lug (last pics) it looks like you had a fair gap round the back and you have needed to much heat and the weld pool has collapsed

 

[Engineer]

Try a 1.6mm tungsten, and filler rod.............looks like too much heat, and too slow travel speed may be a problem, which will be compounded by 2.4 tungsten, and possibly also 2.4 filler?

 

[rtbcomp]

Moved to TIG section.

 

[McG]

Thanks for the replies, it is 1.6mm filler rod that I have been using. I have been trying to use as low an amp setting as possible and yes moving quite slowly along. I find that is the only way for me to keep a steady(ish) hand and maintain a good arc gap. Do you think using a 1.6mm tungsten would have a big effect?

I had figured that I wasn't using quite enough filler rod, do you have any hints or tips on this? Or is it simply a case of adding more filler before moving along?

Excuse me if some of my questions seem very basic, I am just starting to get into TIG welding properly.

 

[Engineer]

Using a 1.6mm tungsten should make things much easier..........the only way to improve actual technique is through practice, and I would suggest getting some scrap material and spend some time on the areas you are not confident with.

Finally if you dont have a foot pedal, then getting good welds will be more difficult, and it would be well worth getting one if at all possible.

 

[hotrodder]

I would suggest getting some scrap material and spend some time on the areas you are not confident with.

x2. I would suggest you start off with some flat plate first as it'll speed up the learning curve i.e. keeping a consistant arc length, controlling/reading the weldpool properly etc is hard enough when first starting out and until you've developed some muscle memory adding the constantly changing angles that go with positional welds on tubing isn't going to help

Some specific things to watch for...



Pretty much the entire weld is undercut which is a killer with respect to fatigue failure- a notch at the surface combined with a localised reduction of wall thickness. Crater/fisheye/pinhole defects when ending a weld... typically the result of abruptly shutting off/breaking the arc and another great stress riser that'll sometimes initiate a crack immediately- the crater circled in red looks like there could be a crack there but could just as easily be a stray arc mark as in the one to the left.



Left circle is a more typical pinhole from abruptly breaking the arc. When these are at the edge of a bracket (along with the missed edge to the right) they're perfectly placed for a crack to grow from as the frame/chassis flexes in use

'Slope out/down' is a great aid in avoiding craters when ending a weld, the current winds down over a preset time either to nothing or a preset crater/finish current after the pool freezes (or done manually with a foot pedal). Adding an extra dab of wire can help too. With more basic kit that doesn't offer slope or a foot pedal then typically you keep the torch moving for example on the final 'tie in' weld when welding around tube you could say keep on going but increasing speed which'd result in the pool cooling and freezing more gradually

With harder, stronger materials like T45 (and especially with the sort of things typically made from thin wall alloy steels) things like undercut and crater defects become a much bigger deal

 

[McG]

Thanks again for the replies, some good tips. I'll try to get some 1.6mm tungstens and get some practice in.

I will have to take another look at the welder settings, I haven't played around with the settings much and I guess I should try and learn everything that each setting does before I try to do any more.

Thanks again,
Dave

 

[gavuk]

Finally if you dont have a foot pedal, then getting good welds will be more difficult, and it would be well worth getting one if at all possible.

If you have a foot pedal then they can be very useful,BUT, i wouldn't rush into splashing out sometimes more than £200 on pedal..Ramp out is often built into machines and can be used very effectively,.....learn the basics of torch and filler rod manipulation on steel to start ...Your welds aren't really that bad ,seen a lot worse,the tag in the last 2 pics lets you down a bit
For more info on pedals look here tig pedal.....If its an ac/dc machine i'm sure it will will have ramp out or ramp down ,check out the tutorial at the top of the page from Tig Paul,and add more filler and practise those starts and stops .... ....