Stainless ???

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Is it normal to have oxidation on a stianless weld after you weld with TIG?  No matter what I try it is oxidized but comes right off with a wire brush.  Also I dont get the neat colors just plain shiny. Is this right?Trailblazer 302 AirpakDynasty 200 DX  Thermal Dynamics Cutmaster 52 CamoMiller Dailarc 250 OLD But great!!2 Miller 140's w/autoset NEW! Millwauke Cold cut sawsDewalt portabandJd2 notcherPipe beveling machine
Reply:The neat colors are an indicator of oxidation.  What is it you're seeing that you believe to be oxidation?
Reply:as said, the 'neat' colours are due to oxidation. they show the extent of oxidation that occured (how hot the weld was when shielding was lost as the torch moved). http://www.bssa.org.uk/topics.php?article=140it's normal but the acceptable 'colour' depends on application...    http://www.bssa.org.uk/topics.php?article=2if the welds are grey then somethings amiss. assuming good gas coverage (no leaks) then typically it could be to much heat input (welding too hot and/or slow) or the other favorite, not keeping the end of the filler within the gas shield (remove it and the hot end will oxidize and the next 'dip' will introduce oxides into the weld)
Reply:the colors  i think you are color blind. look for colors of gold  and purple are pretty much the best that u would want.  how thick is your material
Reply:pics of SS color versus oxygen content in purge gas.http://www.intercononline.com/welding/ypurge.htm
Reply:No its grey oxidation kinda like slag.  It has to be wire brushed every time.  And like I said no colors just shiny stainless. I might have a bad bottle of argon?Trailblazer 302 AirpakDynasty 200 DX  Thermal Dynamics Cutmaster 52 CamoMiller Dailarc 250 OLD But great!!2 Miller 140's w/autoset NEW! Millwauke Cold cut sawsDewalt portabandJd2 notcherPipe beveling machine
Reply:did you properly read the previous posts and links? colour, any colour IS the result of surface oxidation at elevated temperature. brushing a weld/HAZ that is gold, purple or blue will result in a shiney colour free finish too- brushing removes this 'thickened' oxide layerthe colour indicates how much oxidation occured- grey is severly oxidizedcontaminated argon could be the cause (never experienced it or for that matter even heard of the problem prior to reading about it on forums- cylinder filling is more heavily regulated in the UK). the most common causes are...too much heat input (typically begin with 10% less than for carbon steel)not keeping the end of the filler within the gas shield, allowing it to oxidizearc length too long (heat is less focused as arc length increases meaning more is required thus increasing overall heat input). no longer than electrode diameter, preferably 1/16" or as short as possible poor torch angles could also contribute- gas flow directed away from weldit's pretty easy to eliminate shield gas (bad gas, leaks) as the problem- strike an arc, form a puddle and then stop the arc without moving the torch until the post flow stops. the spot weld/tack should be colour freeif the weld is cleaner (better colour) when done without filler then that would point to oxidized filler being the problemif you post details of machine settings and thickness of stainless used we'll be able to tell you if you're in the ballpark with regards to amperage, flow rates, post flow etc
Reply:I have read a couple of threads here over the years where a mistake was made with the shielding gas, and instead of 100% argon, they were running a MIG mix with CO2 or O2.
Reply:yeah, it's a common mistake but one that will wreck the tungsten immediately
Reply:At work we have been delivered our usual big liquified tank that was marked argon but we found out later it had been mis-marked, it was nitrogen.  We couldn't weld anything with it and sent it back to trade for another.  The welds looked like we weren't using any gas at all.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:not sure how familiar you are with TIG, but make sure you are pushing the torch, rather than pulling. also, the color, as everyone has said, is a direct result of oxidation. silver or the same color as the base metal is the best, but gold is very lightly oxidized, fucia/pink/red a little more, purple a bit more than that, and blue is the most. gray, from my understanding is severe oxidation and/or carbonizing of the base metal. in order to combat this, also as previously stated, either move your hand faster or turn down your heat. i tend to turn down my heat a bit so i have more control, do not feel like i am being rushed, and can ensure proper penetration and puddle shape/size.Later,Andy
Reply:I had a problem like you describe, when I fused the SS no problems but when I was adding fill the weld would get a gray look, but it would come off with a wire brush.  The problem was me moving the filler wire in the gas flow.Me!
Reply:Originally Posted by DesertRider33At work we have been delivered our usual big liquified tank that was marked argon but we found out later it had been mis-marked, it was nitrogen.  We couldn't weld anything with it and sent it back to trade for another.  The welds looked like we weren't using any gas at all.
Reply:duplicate postLast edited by William McCormick Jr; 01-17-2008 at 12:39 AM.
Reply:duplicate post
Reply:Originally Posted by FluxIs it normal to have oxidation on a stianless weld after you weld with TIG?  No matter what I try it is oxidized but comes right off with a wire brush.  Also I dont get the neat colors just plain shiny. Is this right?
Reply:Still haven't figured out that "post reply" button, eh Willy Mac?  John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Originally Posted by MicroZoneStill haven't figured out that "post reply" button, eh Willy Mac?