Slag inclusion?

[Russell]

What causes major slag inclusion/ porous welds when all other welds went fine?
Welding indoors and all bare/ new metal

 

[Quattromike]

Damp electrodes possibly or some contamination of sorts

 

[Russell]

It was mig and the steel was prepared the same for all 4 welds. 3 went perfectly but one wouldnt stop going porous like i turned the gas off.
2 of the good welds were done after the bad one.
Ive had this happen a few times with this welder hence the question.

 

[Shovelhands]

It was mig and the steel was prepared the same for all 4 welds. 3 went perfectly but one wouldnt stop going porous like i turned the gas off.
2 of the good welds were done after the bad one.
Ive had this happen a few times with this welder hence the question.

Faulty/sticking gas solenoid?

 

[AHPP]

Is a cartoon character kinking your shielding gas hose as soon as you flip your hood down?

 

[Quattromike]

What’s the condition of the shield and gas diffuser , I’ve seen torches being held a certain way when welding not providing a good gas shield to the weld pool. Somet you have to bite the bullet and fit new liner, diffuser, tip and nozzle before it sorts the issue. Also some folk keep screwing up the gas pressure in an attempt to solve it, make sure your not ott with the gas also

 

[JD450A]

Is a cartoon character kinking your shielding gas hose as soon as you flip your hood down?

Not me I'm afraid

 

[Russell]

I've only got a dial guage not a floating ball type ( been told there not as good) but it was 15 psi now 20 I think. I will check the tip and nozzle.

 

[V8Druid]

I've only got a dial guage not a floating ball type ( been told there not as good) but it was 15 psi now 20 I think. I will check the tip and nozzle.

too high in a draft free environment ... 10 is more than adequate ... you'll chill the weld with too high a pressure .... also as Mike said diffusers and shrouds play a big role in a complete gas shield around the weld .. even the tip if not kept clean and in the shape it arrives in new. Optimum set up is the key to a perfect weld ... MIG or stick or even gas.

 

[Bri963]

If three went well, one didn’t, something was different. Are you sure you’d got rid of all the paint/grease etc. including from the back side of the weld? Did access force you to change your angles? Did you start with a bloody great dingleberry on the end of the wire that really should have been snipped off? In my experience a lot of people skip snipping the melted blob off from the last run, and when you think about it, this blob needs more power to melt than the run of wire once the weld starts flowing, and is often the reason for porosity at the start of the run. Keep some side cutters handy and use them.

 

[heritage machining]

What gas are you using hopefully not the small disposable bottles they are rubbish Also if mig/mag 2%25%73% oxygen co2 argon is good mix for regular steel I have to admit I don't usually clean what I'm welding as well as I should however I do usually weld spray method

 

[Giles]

We’ve a small 13amp mig that’s a pita to get a good weld with compared to the big Lincoln ranger 10-lx with ln-25 wire feed. The little unit you need to have the hose straight and shroud clean etc it’s a lot less forgiving than the big unit. Also was the bad weld more exposed to door open etc or a draft?

 

[doobin]

I've included plenty of slags in things over the years... no longer, however!

 

[6feetdown]

I've included plenty of slags in things over the years... no longer, however!