I was just at a friends shop and I was welding some stainless steel, and the welds came out very grey and brittle looking. I have been welding for many years, and I know that this will happen if your heat is to high, and if you are burning through. This is not the case. No matter how long the weld goes, it will look really burnt until the last 2 or 3 rings, which will look nice and shiny. Gas coverage doesnt seem to matter either as I tried welding with many different settings. I am also using a gas lens and thought it could be clogged and changed back to the original cup, and no difference. The machine is a Miller syncrowave 180. I know it is hard to tell what is happening with no pics, but I have no way of getting pics on here. I am just wondering if anyone else has had this happen to them, or maybe the machine could use some servicing.

 

I've had that happen to me before. It seems like welding stainless is never very consistent. Some stuff welds so nice and easy and other stuff is just awful. I bought a vibrant SS 3" U/J bend and the stuff was just pure crap to weld, then again i'm not that great at welding.

 

details

amps
gas flow
size of cup
post flow

and if there dark looking i would guess poor gas coverage, as you can use to much heat and the weld will look odd, but if you have gas coverage it can still have proper color.

 

you got poor gas coverage, thats all. bump it to 18-21cfh and smile.

 

If your on the verge of burning through, your heat is way too high. I would suggest turning up the flow of gas a tad, and moving a little quicker, without soaking the part in heat. Backpurge or Solar flux as well!

 

what thickness how many amps etc etc and so on.

Run some fusion beads and keep turning the heat down until you get the color you want. Then start turning the heat up and adding gas flow until you can maintain that color. THen worry about adding filler. You have to eliminate the possiblity that you are too hot.

 

It sounds like you are traveling to fast.What happens is when you go to fast the weld is still hot but its not being covered with gas.So it oxidizes the weld.Just like when you stop and pull the torch away to soon.

 

Could metal quality have anything to do with this? I've seem some very crappy stainless blends coming out of India...

 

I've never welded stainless that shitty....yet

The answer lies in why you have color over the area your postflow is covering. I'm 99.99% sure it's operator error and not the machine or the material.

Don't take that too personal. Operator error is the leading cause of shittastic welds of all kinds in all processes.

 

doing pipe is a bitch because u need to make sure your gas is flowing over your bead evenly, or else itll just bugger off and your weld will gray. this is why u can get a butt weld or fillet weld so "nice" looking.


honestly theres nothing wrong with a gray weld that is cause by poor gas covered, wire brush it and its fine. if u burn the metal there is a chance it could rust on you.

the weld "bling" that goes on in the car forums is rediculous, people think that if the weld is all pretty and shiny on the outside its a NICE weld. most people do not show in the inside of the weld, becuase they are not getting full penetration and not back purging. the rear of the weld should be just as nice as the outside.