how clean does steel have to be for mig

[slickmcvic]

I'm new to Mig welding after having experience in oxy-acet & arc welding courses. My question is does steel have to be sanded or ground clean before weldin or will i get away with just welding on unrusted steel.

 

[dstealth]

Unrusted steel is fine for MIG welding. It is best to wipe off any dirt or oil though.

Chris.

 

[Woody.v8]

It is best to wipe off any dirt or oil though.

Chris.

Yea just tell that to any production welders

 

[Robotstar5]

Yea just tell that to any production welders

We had to install extraction hoods after our manual weld booths due to complaints about the burnt oil fumes coming off the components

 

[Woody.v8]

We had to install extraction hoods after our manual weld booths due to complaints about the burnt oil fumes coming off the components

Tell me about it, Ive spent years welding components /plate etc with oil/ mill scale and general ****e on them, Who knows what damage has been done . Only now are respirators becoming the norm, But what harm those few thousand hard facing rods and copious amount of oil have done , Anyhoo that's my senior moment over

 

[TechnicAl]

the cleaner the better

 

[Richm]

Had a mate in army, metalsmith that got golf ball sized growths, aparently from the new welding buildings at the corps school when he did his class one course, extraction was not up to scratch for welding chobham armour, were told to carry on anyway...

 

[Justme]

Thought chobam was "glass" under a thin metal coat?

Just googled

Although the construction details of the Chobham Common armour remain a secret, it has been described as being composed of ceramic tiles encased within a metal matrix and bonded to a backing plate and several elastic layers. Due to the extreme hardness of the ceramics used, they offer superior resistance against shaped charges such as high explosive anti-tank (HEAT) rounds and they shatter kinetic energy penetrators.

 

[Sparkey]

Yea just tell that to any production welders

huh yeah, tell me about it!!!!! i'm sniffin' that all day long! guess it makes you a bit crazy in da coconut after a while...haaaahaaahaha
But yes, it's better to wipe it off before welding it, unfortunatly i don't have always time for that...
Sparkey

 

[MINGER]

i agree with technicAK, the cleaner the better, i did a course at collage years ago, the teacher there showed us a small piece of mild steel with a straight flat weave mig weld on it, the weld was about half to three quarts on an inch wide, it looked a specimen weld. He asked us if we could see anything wrong with it, no one could find fault at all.

He then pointed out a very fine crack at the side of the weld, so fine you could not see till it was pointed out, we heated the sample up a tad and the crack grew bigger, the upshot of this that the weld was stuck to the mettle, it looked perfect, but in fact there was no fusion at all, the weld was virtually just sat on top of the mettle, he told us that this was due to not cleaning the plate properly before welding.

This sounds hard to believe i know, but it is true, if any of you lads who are at collage ask your tutor about this possibility.

The course i did was at Rotherham Collage night school, the teacher war a real big guy called Stuart, anyone in the Rotherham, area, in the welding circle will know him. He loved VW Beatles, strange guy eh? But you wouldn't tell him that






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