Criticise my Mig welding practice - pics

[Kinky John]

Hello all,

I wonder if you can openly criticise my attempts at welding for quality and to see what i may be doing wrong or what i could try to do to improve upon them.

Ive been practising on and off over the last fortnight now. My machine is a SIP 130 Turbo Migmate.

I believe the metal is 1mm thick although it could be 1.2mm, im not sure i dont have calipers. Im using 0.6mm wire, Ar/Co2 gas.

After experimenting, ive got what i believe is a fair balance of power setting (low volts>medium or equivalent to 2nd lowest setting of 6) and wire speed to give a steady crackle. Getting a better result on this setting leads me to believe the metal is slightly thicker than 1mm.


On both pieces (below), the left hand weld is a lap weld and the one on the right is a butt weld.

Reverse:

All these are butt welds

Reverse:

My main question at the moment is about penetration. If you look at the reverse i cant get the weld all the way through. I seem to have reached a limit now in my ability as i cant successfuly improve on the examples above for penetration. Higher WFS and i get excessive spatter and hole buring if im not careful. Higher power and lower WFS and there is still what is clearly too firece an arc. Lowest power and higher WFS, i get a tall weld and no penetration at all.

At my present settings i feel i am getting a reasonably good shape on the welds (not too tall or flat) and i feel there is a good balance of settings. I am obviously still having problems seeing where im going and holding a straight line !

Ive tried from a stitching method (quick weld, quick pause etc) to running a weld for as long as i can.

From what iv been readin ive been wondering if perhaps the Ar/Co2 gas is cooling the weld off too quickly and would be interested to know what may happen with Co2 but ive ran out of that now.

Anyway, any tips would be welcomed at this stage,

Regards

Mark

 

[malcolm]

Don't go for pure CO2 - it's similar to the argon mix but messes up the arc stability making welding a little more tricky.

The beads themselves look nice - looks like you've got the hang of things. But the penetration is a bit slack. You can keep on going until there's more penetration on the back of the weld than weld at the top without risking blowing though.

Try welding for a bit longer without stopping - you seem to be stopping every 1/4 inch at the moment so all the heat is lost when you get going again. Try upping the amps a little to find the point where where you blow through too. A bit of weaving motion with the torch while you weld might help a bit - it's good for a lot of things, but the best thing is it controls the welding speed quite well and increases the difference between nice penetration and blowing through.

 

[irondarren]

You want an honest opinion ?

Your doing small runs, your stopping and then starting again which is fine, saves burning holes. But each time you start you are leaving a slight gap between where you started and where you finished. Look at the third photo bottom right this is the only one that you have started from where you have finished, now look at the fourth photo, I am assuming you have flipped the steel top to bottom which makes the weld i mentioned now the top right, it has the best penetration out of all of them. As Malcolm said weave left and right that will improve penetration and should aid in not burning holes.

Well done for posting pics of the welds to the forum, imo its the best way to get advice on whats going wrong.

Are you pushing or pulling the torch along the weld, and what sort of welding helmet are you using

 

[tonybmw]

Hi

I am new to this forum but in my opinion you are almost there, I would recomend the next power setting up and just tweak the Wire speed up also. Turning the power up without the wire speed will normally mean that the wire will burn back into the shroud, and turning the wire speed up by itself will mean that the weld will splatter and stack up on itself, you have the settings proportionaly right, just not quite suitable for that thickness of material.

The beauty of welding in short bursts is that you can weld with a higher setting and get better penetration, welding in short bursts also helps to minimise distortion when welding thin plate and repair panels. Welding on longer runs will help to build up heat and therfore penetration also, but more heat also means more distortion.

I personally always push the welder into the weld, as quite often pulling it, can lead to stacking up of the weld as it builds on top of itself, but this can be a useful technique to prevent blowing through on very thin repairs

Keep on Practising,

Regards

Tony

 

[malcolm]

Welcome to the forum Tony - some good advice there.

 

[Kinky John]

Thanks for your advice malcolm, tony, irondarren, its all much appreciated. And yes, i want it as frank and honest as possible, im not here to have my ego massaged, im here to successfully learn mig welding.

In answer to the points raised:

I have an autodarkening helmet so both hands are free.
Yes, i have flipped the steel top to bottom in the pics

Ive had another practice, pics below, this time upping the power again as suggested. I have been experimenting with both weaving and a back and forth motion on the welds below. Ive also tried to tighten up the spacings from when i start again after stopping. I havent tried to run a weld for more than an inch or so before stopping.

The welds below are all butt welds on power setting 3 or coarse volts low>high setting. I find that i have a small window in WFS to get an acceptable weld bead.

Starting from left to right, the 1st on the left is with the higher end of acceptable WFS, above which i get excessive spatter and too high a current, the arc sounds very aggressive and also the bead becomes way too flat. Also, above this WFS i hvae to move the torch quicker to avoid burning through such that then i dont really get any penetration

2nd from left is the lower end of acceptable WFS below which i get a tall weld bead with no penetration.

The middle weld is a WFS set midway between the previous 2

The 4th and 5th welds have combinations of WFS in them as i then experimented within what i think is the acceptable WFS range.

I think its fair to say that the penetration is better than in the first set of pics. However, im still only 50% satisfied with it as compared to what i think it should be like.

As i see it, my problemn is that i seem to require either more power or slower torch travel to get acceptable penetration. However, if i do this by increasing WFS i either start burning holes, get too flat a bead, have to move the torch too quickly or get excessive spatter. Slower torch movement either sees weld build building up on it self or hole burning.

Also, to be fair, overall i actually think that the welds above are too flat due to too high a power, so i could do with a more experienced eye from someone to make a judgement on that

What do you all think? Do i just need to continue practising technique on this power setting? I feel that by now i should have moved on from the level of still adjusting settings but without someone who knows what theyre doing looking over my shoulder its difficult to know when my errors are as a result of underdeveloped technique or actual incorrectly balanced settings if you get my drift.

I think that ive started to get more of a feel for settings and for what makes for a satisfactory arc. However, i still feel im missing something (but i dont know what) in order to be consistent and be able to replicate what ive done. I still feel that when i get a good looking bead its as a result of chance rather than i knowingly got set up right beforehand.

Regards

Mark

 

[irondarren]

Ok looking at the pics, i think you might be a little low on your gas flow, which should be around 10 lpm, turn up the gas, looks like holes in the weld

 

[Kinky John]

I must admit i have reduced my gas flow in order to extend the life of my bottles while im practising - otherwise id have spent a fortune by now if id got the valve right open. I shall try opening the valve a touch more though.

Whats your view on the level of penetration?

Ta

 

[malcolm]

I think you are off track. Save the thin metal stitching technique for 0.8mm sheet and go for continuous welds. That will help you get rid of the inconsistent penetration and figure out where you are.

The holes are the sort of thing you would expect at the end of a weld. The gas would be too low if you end up with bubbles in the weld or a brown covering over the weld. The weld should be clean but you might get brown stuff either side.

Go on - try a continuous weld and don't wire brush it before the photo.

 

[Kinky John]

Malcolm, could you expand a little more on how im going 'off track'. I assume you mean in my efforts to use a stitching/pulsing technique

I will try your advice regards going for a continuous weld at next practice

I do get a brown covering to the surface of both the weld and surrounding metal and i did wire brush it off before taking the pic - youve done this before havent you?
A little more gas then.

Also, ive been leaving a gap between the edges, no more than the thickness of the metal but from another recent thread on what size gap to leave, i get the impression that perhaps i should try leaving no gap on this thickness of metal - is this correct?

Ta

 

[malcolm]

Malcolm, could you expand a little more on how im going 'off track'. I assume you mean in my efforts to use a stitching/pulsing technique

Yup
It's a great technique for really thin metal, but a bad technique for anything over 1mm. Main reason not to do that when learning is short spludges of weld don't give you any feedback about whether your power settings are OK, and don't let you develop a technique. Contunuious welds are the way to get technique together - and that'll make life soo much easier in the long run.

I do get a brown covering to the surface of both the weld and surrounding metal and i did wire brush it off before taking the pic - youve done this before havent you?

Yup

Also, ive been leaving a gap between the edges, no more than the thickness of the metal but from another recent thread on what size gap to leave, i get the impression that perhaps i should try leaving no gap on this thickness of metal - is this correct

Yup
Darren posted recently not to leave a gap in anything less than 2mm sheet (from memory). That's quite right for anything other than 90 amp welders. The gap reduces the power you need to get full penetration (shaping the joint into a V and leaving a gap goes even further). For metal less thana 2mm don't leave a gap - direct contact between the two sheets will help tame the MIG and make life much easier.

 

[Kinky John]

Ahhh!

I understand it much better now from your explanations. I see!

Youve given me half a dozen answers to things i knew i was only making a best guess at.

For example, I thought it was crucial to leave a gap on anything above the thinnest of metal ie 0.8mm as i seem to have believed that would aid penetration. And i thought that pulsing rather than continuous welding was the technique to aim for.

I understand now that continuos welding to develop technique and learn consistency is important and that directly touching the edges of the metal when butt welding (the thickness i have) is the correct method.

I'll shall be practising again tomorrow feeling a bit more confident with this new light on the subject and i will take more pics. Many thanks malcolm,

Mark

 

[Kinky John]

Hello again,

I think ive made a small step in quality today:

The weld on the left is with power setting 3 (coarse volts low>high). The weld on the right is with power setting 2 (coarse volts low>medium).

Using a continuous welding technique, i have much better penetration although still not 100% (but wasnt aiming for that straight away) but i can see this is the way forward.

I seem to think that im generally getting equal levels of penetration on the lower power setting by adjusting WFS up slightly (to get most stable arc) and torch travel speed down. I think the one on the left (high setting) is a little too flat, but i need another experienced view of that.

I did notice, pic below, that the metal on the right (lower power) is markedly more distorted than on the higher power. I guess the lower torch travel speed with the lower power actually serves to build up more heat overall than the higher power but with a faster torch travel. Is this so?

Whats the view, which is the better technique to go with: a)higher power, faster torch travel or lower power, lower torch travel? Of the 2, the left weld i think looks best but i dont know any better!

I did up the gas rate as well. And I do have to work on preventing that initial high build up when i start off from the end of a previous weld. I'll try for another few runs tonight before sundown i just wanted to ask which of the power settings/torch speeds seems the best to aim for

Thanks

 

[nash bap]

I am a newbie too and am following the tutorials carefully(big help, thank you). I now know what the back of a butt joint in sheet metal should look but have no idea how much penetration to expect when doing a lap joint in sheet metal. Should I look for some bubbled metal or just discoloration? I have searched this forum for pics but can't find any. Can anyone please explain.

Thanks.

Nash

 

[shenion]

Here's a pic of 100% penetration:

Weld is near symmetrical top and bottom.

These were just beads on 1mm steel. Expect a butt weld to have a bit more uneven penetration.

I normally use a bit less penetration/heat. Would have been better with thinner wire. The above tests were done to compare different gas mixes.

 

[nash bap]

Thanks Shenion. I have seen these pics before but my question relates to penetration on lap joints. Any pics on that?

Nash

 

[Kafer_meister]

I've got a sip 150 at the moment and can get good penetration on 1 - 1.2mm steel on the lowest setting. I found that turning the wire speed down to fairly slow produces a better weld. I may be wrong, but it seems to work well for me.

 

[zardoz]

your latest welds were an improvement over the first. Although you say that you are no longer 'stitching' the welds with a small gap between each, are you still stopping and starting ?

 

[FireStorm]

looking at the weld zardoz, it looks like he is stopping and starting.

What you could do is stop let weld cool down for a second or so then weld on top of end of weld so it melts in giving you a nice run of weld.

looking good which my sip 130 turbo did that!!!!!

 

[tonybmw]

John

Definetley a huge improvement over your first samples, I am intrigued as to why you think the left weld is too flat, flat is not bad, to me it shows good penetration, little heat distortion and less metal to grind off if needed, I would even try the next power setting up if you are going to use short stitches, this will help to achieve more continuos and full penetration, if you then end up burning through constantly, you then know that the previous setting was the best one and then you just need to work on your technique a little more.

Good effort

Tony