Weak welds with mild steel...

[Guy Burnett]

Hello,

I have recently bought a Clarke 135TE with the intention of welding together some mild steel structures. I have carried out a number of tests on 1.5mm thick mild steel tubing and have managed to weld pieces together. However the welds are very weak, with a bit of force I am able to pull them apart.

I am using the CO2 gas that came with the welder and 0.6mm wire. To start with I used the control settings that the manual suggests (Welding Position - 1 & Max, Wire Speed 6 and gas flow on 4) however I have also carried out tests with other settings.

My work surface is a large 3mm mild steel sheet. I am working in a large garage with the door but there is no draft.

I have watched tutorials and used the manual throughout but obviously I am doing something wrong. Any help you can give me would be hugely appreciated! I have attached some photos of the steel after I have pulled the welds apart.

Also, if you may know someone in London, UK, who might be able to help me that would be great!

Many thanks,

Guy

 

[mike 109444]

Are you sure that is 1.5 thick?
It looks a lot thicker.
Looking at the second pic bottom part of the image, the weld has not penetrated and is sat on top of the metal (even has a gap). You may need to up the power. Even going up a wire size should put more power in as well. But if as it looks like it's 3mm thick tube then you may need a little V prep to the joints.
Try running some beads on a piece of flat 1.5 and you should be able to blow through on the higher settings.

 

[cumbriasteve]

I think you have missed a stage as a new welder and that is the initial practice on flat plate, those are just variants of rough tacks with no penetration at all.

As Mike mentions get some scrap plate, some 2mm or 3mm would be ideal and get used to producing runs of weld, playing around with the power and the wire speed and getting used to holding the torch correctly.

In my opinion the small disposable bottles of co2 are a waste of time, there is very little gas in them and it can be hit and miss if you have the valve open at the right position to supply the desired flow, as those welds tend to show.

 

[norlander]

0.8 might be better but 0.6 should get it done on 1.5. I learned that pulling the gun gives more penetration so try that if you have been pushing.
Have you got the wire at the leading edge of the pool/puddle as you weld?.
Also, what is your gas set up?-if it's disposable bottles, I found them to be poor for any serious or decent weld results.

 

[rtbcomp]

If you're using disposable bottles the chances are you've run out of gas. They last about 10 mins and you need the regulator fully open to get a decent flow of gas.

 

[steveo3002]

yeah i need my gas nearly fully open , trigger the handle near your ear and listen for the hiss of gas

im far from an expert , but crank it up high until its blowing holes then back it off a bit until you get a feel for it

 

[GordonC]

Turn the power up to number 2 low and put the wire speed down to about 5 and a half no higher and see how you get on with that mate. By the looks of it the power is too low and not penetrating and I would say the wire speed is a touch high at 6 aswell.

 

[cumbriasteve]

Turn the power up to number 2 low and put the wire speed down to about 5 and a half no higher and see how you get on with that mate. By the looks of it the power is too low and not penetrating and I would say the wire speed is a touch high at 6 aswell.

With most other machines I would agree regarding the wire speed but I have the same model the OP has, they are a great machine but a right sod with wire speed, no matter what I weld the wire speed is never below 7 and usually above 8.

For thin metal mine is set at 7.25 and for 4mm it is set at 8.5 and yes the small fractions are essential to get right, even a quarter turn can send it a mile out of the 'sizzle' zone.

Not sure if all Clarkes are the same but a forum member was round last week and he said his 150 was the same.

 

[GordonC]

With most other machines I would agree regarding the wire speed but I have the same model the OP has, they are a great machine but a right sod with wire speed, no matter what I weld the wire speed is never below 7 and usually above 8.

For thin metal mine is set at 7.25 and for 4mm it is set at 8.5 and yes the small fractions are essential to get right, even a quarter turn can send it a mile out of the 'sizzle' zone.

Not sure if all Clarkes are the same but a forum member was round last week and he said his 150 was the same.

Ah fair enough mate

 

[rtbcomp]

yeah i need my gas nearly fully open , trigger the handle near your ear and listen for the hiss of gas

..........

With the wire feed disabled.

 

[steveo3002]

With the wire feed disabled.

half trigger i should say ...then the wire doesnt come out

 

[lshigham]

half trigger i should say ...then the wire doesnt come out

Only on the cheaper torches with the gas valve in the torch handle.

At risk of ending up with a perforated ear drum, it's probably best to disable the wire feed anyway.

 

[Kent]

Get onto a bead pad and run some beads, lots of beads- forget the joints for now. Experiment and get used to running beads, if you put touching beads all over a 200mm2 2.5-3mm thick pad in decreasing squares starting at the edge (once you find your setting) your getting someplace

Turn the thing up to full welly on the pad wire and power and work backwards in settings wire first, get the feel of the plant, listen for that sizzle (people say like bacon in the pan). Look at the penetration and most importantly keep your wire feeding into the leading edge of the puddle, forwards on back, up or down the wire needs to feed into the hot crater- not the mid point on the bead that's already cooling.

Never used 0.6 wire in my life, if I was on super thin car bodies I might but you can go down to 18 SWG on 0.8mm solid wire

 

[Richard.]

^^^^
As said above I agree entirely with the fact you should be starting off with every thing maxed out and work down till your arc is crackling away (yeah a bit like a frying pan)
And for sure you should avoid joints if you can't get them to stick
Do some runs on a bit of scrap but treat that scrap like the job so grind off any scale and rust and tune your welder up to singing away.
With regard to your joints not sticking the box in the pic does not look like 1.5mm wall it looks closer to 3mm but I could be wrong.
Your also trying to do several joint types at once by having it at 90degree. Once your happy with your beads on a plate you should then go to a butt joint. Given the power limitations on your unit and the fact that penetration is not happening don't butt the two pieces right up leave a 1mm gap between them and tack both ends
Then a hot run in the gap should join them up strong.
Do the beads first then start with the butt joint
Then post some pics.

 

[fizzy]

When I was a raw beginner I found the best way to set the wire speed/amps was to use someone else to operate the torch and I would adjust the settings by sound alone!!!
Listen to some welding videos on Youtube by good welders - then match the noise.
I am still a beginner - just not quite so raw!!!

 

[Guy Burnett]

Are you sure that is 1.5 thick?
It looks a lot thicker.
Looking at the second pic bottom part of the image, the weld has not penetrated and is sat on top of the metal (even has a gap). You may need to up the power. Even going up a wire size should put more power in as well. But if as it looks like it's 3mm thick tube then you may need a little V prep to the joints.
Try running some beads on a piece of flat 1.5 and you should be able to blow through on the higher settings.

Thanks for this. The steel is definitely 1.5 - 2mm thick, I will give it another go.

 

[Guy Burnett]

I think you have missed a stage as a new welder and that is the initial practice on flat plate, those are just variants of rough tacks with no penetration at all.

As Mike mentions get some scrap plate, some 2mm or 3mm would be ideal and get used to producing runs of weld, playing around with the power and the wire speed and getting used to holding the torch correctly.

In my opinion the small disposable bottles of co2 are a waste of time, there is very little gas in them and it can be hit and miss if you have the valve open at the right position to supply the desired flow, as those welds tend to show.

Hi Steve,

Thanks for your replies. I did practice on a flat plate to begin with but I probably moved on too fast. Also I wasn't sure what I was looking for/trying to achieve when doing this. I will give it another go using all this advice.

Cheers

 

[Guy Burnett]

Get onto a bead pad and run some beads, lots of beads- forget the joints for now. Experiment and get used to running beads, if you put touching beads all over a 200mm2 2.5-3mm thick pad in decreasing squares starting at the edge (once you find your setting) your getting someplace

Turn the thing up to full welly on the pad wire and power and work backwards in settings wire first, get the feel of the plant, listen for that sizzle (people say like bacon in the pan). Look at the penetration and most importantly keep your wire feeding into the leading edge of the puddle, forwards on back, up or down the wire needs to feed into the hot crater- not the mid point on the bead that's already cooling.

Never used 0.6 wire in my life, if I was on super thin car bodies I might but you can go down to 18 SWG on 0.8mm solid wire

Great, thanks!

 

[Guy Burnett]

^^^^
As said above I agree entirely with the fact you should be starting off with every thing maxed out and work down till your arc is crackling away (yeah a bit like a frying pan)
And for sure you should avoid joints if you can't get them to stick
Do some runs on a bit of scrap but treat that scrap like the job so grind off any scale and rust and tune your welder up to singing away.
With regard to your joints not sticking the box in the pic does not look like 1.5mm wall it looks closer to 3mm but I could be wrong.
Your also trying to do several joint types at once by having it at 90degree. Once your happy with your beads on a plate you should then go to a butt joint. Given the power limitations on your unit and the fact that penetration is not happening don't butt the two pieces right up leave a 1mm gap between them and tack both ends
Then a hot run in the gap should join them up strong.
Do the beads first then start with the butt joint
Then post some pics.

This is a great help thanks. I will carry out some more tests and take some photos.

 

[Guy Burnett]

When I was a raw beginner I found the best way to set the wire speed/amps was to use someone else to operate the torch and I would adjust the settings by sound alone!!!
Listen to some welding videos on Youtube by good welders - then match the noise.
I am still a beginner - just not quite so raw!!!

OK cool thanks.

I am definitely still a beginner!