Any advice?

[Boss]

Havnt welded tig for about 5 years now so I'm rusty as hell and am now realising that my 2 years at college barely scratched the surface. I bought a maxtra POS and finally got it running. Can people let me know what they think, any pointers to make them better?(apart from the shakeyness) admittedly not much cleaning went on in the pics and am Wondering if that attributed to the blue weld?

This is the chassis for my tube bender that
I am converting to hydraulic. Ignore the mig, not my best work

 

[J.B. Welding]

I'de give you job mate. Practice makes perefct>?< Don't forget to keep your tungsten super clean and maybe drop the heat a bit if its bluing? Good luck with your project!

 

[backpurge]

The weld discolouration is perfectly acceptable, better this than turn the juice down and not get enough fusion

 

[Boss]

Good to know, cheers fellas.

I want to brush up on it because I'm going to tig weld my tube frame,thought using a 2.4 rod so I got a little more coverage with a 2.4 tungsten and a gas lense would be ok.

Does that sound correct or do I need a bigger tungsten?

 

[Bristolbulldog]

Wish I could tig that well!

 

[Boss]

It's not as good as the pics make out, the lousy iPhone camera hides a multitude of sins

 

[Mid Wales welder]

Looks good, I found sometimes just 1 extra litre per min on the gas can help with the bluing.

 

[Boss]

So is the blue a sign of gas starvation?

 

[hotrodder]

No, it's just 'heat tint' aka temper colours. Everything gets more reactive at high temps so heat steel in air and the surface oxidises. As temps increase the oxide layer thickens which refracts light differently producing various colours, initially yellows/straw which darken through reddish browns, purples and then blues as the layer thickens (still crazy thin though) before turning opaque grey like the root side of the outside corner did as it cooled from molten in the air

The colours that form while welding depend on all sorts of things including surface finish of the material, millscale for example is a thick oxide layer...
Also take the outside corner weld which is undersized for the plate thickness. Obviously with thick plate/heavy wall pipe that's dealt with by additional passes to fill and cap the joint but with thinner stuff that can be welded in a single pass there's less material to act as a heat sink and so the colouring typically changes i.e. it's easier to get 'good colour' or even no colour on thick stuff than it is with thin

As Backpurge said, worry about heat tint colours and you can easily end up producing undersized welds with LOF (lack of fusion) defects which is a FAR bigger deal. When it is actually important (titanium, corrosion resistance of stainless etc) various other things are done for example purging the backside of the weld and removing heat tint with pickling pastes or using trailing shields to increase argon coverage

 

[Boss]

Wow, thanks for that, very insightful. I did move a little faster on that pass just to see what would happen but diddnt realise you could get the temper colours within the weld. There was another pass over the thick plate but I deleted the photo from my phone, first attempt at a weave, had no idea how to do it and it diddnt go well.

 

[Boss]

Yeah, it diddnt go to well. I ordered a few bits the other day so I can use a thicker rod. Going to have another go tomorrow.

Also looking at one of those parweld ergo grip torches, anyone had any experience with them?

 

[Boss]

Had a bit of time on my frame over the past few weeks and i seem to be munching through tungstens I don't know if it's because I'm doing something wrong or if I'm pushing it too far but they ball up pretty quick

 

[backpurge]

I would avoid putting such a large weave down as there is always going to be the danger of centre line cracking, particularly if you don't get enough filler wire into the joint, you are far better off using stringer beads

Also you could do with tying the ends of the welds in a bit better, especially if it is a component that is going to have any sort of stress on it, these are just minor points and your welds do look pretty good.

Your comment about the tungsten balling up is interesting, this is normally something that only happens when you are using AC, what colour is the tungsten when you have finished a run? A photo would be handy

 

[Boss]

I did not know that, thanks. I ran a run to fuse it then put the weave over the top.

It's a red tip tungsten, I grind it twice and take the tip off.
I thought it maybe a lack of gas as I only have a no 5 ceramic at the moment.

 

[backpurge]

Is your post weld gas flow running for long enough

 

[Boss]

I will have a look and play today. And add some more pics.

 

[Boss]

So I found a no8 ceramic and I turned up the post flow a little, still not behaving quite right

Start

First run

2nd

Full length on the other side. About 3/4 through this the arc started wandering around

Making me out to be a bit of a liar as it isn't as bad as it has been lol.
Am I asking to much out of a grind or is this normal? Welcome any constructive criticism but be gentle with me lol

 

[Lawnmowerboy]

A good rule for postflow is a second for every ten amps.

 

[backpurge]

Not sure you mean by "asking too much out of a grind" but your tungsten looks to be getting contaminated from somewhere

 

[overload]

When you grind your tungsten, make sure not to overheat the tip, and don't bother grinding the tip off. Keep it sharp.