First MIG Welds, advice please

[saysomestuff]

First (EDIT-Second now!) MIG Welds, advice please

Hi Guys,

I've been lurking around the forum looking for advice on a machine and reading up on technique for a couple of months now.

I previously had a go with an old arc welder but the tube i was welding was way too thin (about 1mm) so decided that seeing as I have quite alot of welding to do on my VW project I should probably learn to MIG weld properly.

Finally got all my goodies together and had a crack this avo with my new Sealey superMIG 140, auto-darkening mask and proper gauntlets. I used the calculator to choose the initial settings (power 1, wire 5/6) and adjusted both power and wire speed quite alot to see if I could learn the differences/errors.

Using Argon/CO2 disposable I tried pull, push and weaving so there's not much consistency - I noted down what I did on each weld on the numbered sides as I didn't just fill side 1 then 2, i rotated to let the metal cool a bit so I can map your comments back to settings/techniques I used.

So anyway, I'd love some advice on which welds look sound, which look horrific etc:

SIDE 1

SIDE 2

SIDE 3

SIDE 4

 

[Furry Freak]

It looks to me as though you are building up 'scales' of weld there rather than laying down a bead. In other words, you are laying all of your weld in a sort of pile. Not sure what power you are on, but I would go higher if you can, check your gas flow is high enough and weave less. Try aiming through the steel with the tip if you follow me and go with a single line to start with. Essential to get penetration into the parent metal.

Metal looks clean enough with only a few cavities. Certainly has the makings of something in my view.

FF

 

[Sparkey]

Hi!
For almost all of the welds you lack shielding gas...or it get's blown away or you keep your torch too far from the workpiece...
But there's one bead on the number 2 pic that is quite good, the one on the top...
Other than that your welds seem a bit "cold" you should up the power a bit or decrease the wirespeed!

And try not to weave at first, you can always do that later! For now you need to search for the frying bacon sound!
Hope this helps!

 

[malcolm]

It's a lack of shielding gas sure enough. That's very common with the disposable bottle regulators. Some way to check flow rate with those things is a must - too little and you get what you got, too much and you waste gas. Peashooter is the cheapest way to check.

Depending on the regulator they often need to be turned down to max to get any gas out. Wind will blow shielding gas away - wind breaks are effective.

 

[saysomestuff]

Wow, thanks so much for your detailed responses, the more I think about it, I hadn't made any effort to shield the work although it was a pretty calm day.

So today I thought i'd finish of the little reel with some of your suggestions, here's the results, only managed 4 goes before the wire ran out.

I think I managed to get the sizzling noise quite a few times this go although it would also have a bit more of a crackly quality at intervals.

anyway, first 3 - i turned the current up to 1 max after the first weld and they're all on wire speed 4.

final one.

an inside shot

I think tbh that I'm still moving the torch too fast - it's a habit I picked up from the arc welding as the material was so thin - I've tried to slow down and hold the torch closer but at points i felt definite 'burnback' which i think might've been what caused the crackling.

Also, for reference, here's the arc welding I did last month (it's gone a bit rusty now) showing that i was too far away and moving too fast (i think!)

 

[dai]

Wow, thanks so much for your detailed responses, the more I think about it, I hadn't made any effort to shield the work although it was a pretty calm day.

So today I thought i'd finish of the little reel with some of your suggestions, here's the results, only managed 4 goes before the wire ran out.

I think I managed to get the sizzling noise quite a few times this go although it would also have a bit more of a crackly quality at intervals.

anyway, first 3 - i turned the current up to 1 max after the first weld and they're all on wire speed 4.

final one.

an inside shot

I think tbh that I'm still moving the torch too fast - it's a habit I picked up from the arc welding as the material was so thin - I've tried to slow down and hold the torch closer but at points i felt definite 'burnback' which i think might've been what caused the crackling.

Also, for reference, here's the arc welding I did last month (it's gone a bit rusty now) showing that i was too far away and moving too fast (i think!)

the arc weld looks a bit cold to me

 

[saysomestuff]

Thanks, was using really low amps as that tube was 1mm or less - I'm not too worried about the arc as I'm boning up on MIG to redo that frame.

 

[redwine300]

Hi saysomestuff, Firstly, welcome to the forum, I'm sure you will find the guy's here as friendly and as helpful as I have, As i have benefited so much, i feel it is only fair to try and put something back by way of passing on my experience so as to hopefully be of help.

Looking at your latest pictures I would suggest reducing your wire feed slightly and trying the next higher power setting. This may allow the weld pool to form more penetration and encourage a slower travel speed at the same time. If I am correct, I think you should be trying to achieve the same bead height above and below the metal. Also, it may be worth looking at your torch angle, looks a little low, this may explain the loss of shielding gas. Again, these are only my thoughts and hopefully the more experienced guy's will either concur or disagree, but I'm sure they are worth some exploring just to see if you get a better weld.

 

[Wozzaaah]

Saysomestuff, I'm going to be fairly blunt here but hopefully you won't take offence.
Those welds are pretty awful!
If you look at the edges, they sort of 'roll under' the bead which indicates that there's little or no fusion. In weld-testing terms that's classed as a 'serious' defect so is something you need to try and avoid.
You also have no travel speed or arc length consistency so hold the torch in your dominant hand, steady the neck on the index finger of your other hand and try and relax making sure you're breathing properly.
Up the power too, that will get the bead flatter resulting in better fusion and penetration. You may also have to reduce the wire speed a touch but if it starts to form 'blobs' which drip into the we;d pool then you've gone too low.
Try adjusting the wire speed control as you're welding, go up it until it starts to stutter and tries to push the torch away then back it off until it stabilises and sounds nice. Go down until it starts to hiss and 'blob' then back up again, you'll soon get a feel for what works.
Am I mistaken in thinking that the box section you used was previously painted and that you've just wire-brushed it?
If so then that won't help, take a grinder to it until it's shiny, any contamination, oil, paint, galvanising will seriously affect your welding.

Hope some of that's useful, look forward to seeing how you get on.