TIG, Stainless, and Heat Tint

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I've been lurking for a while, and finally decided to register. I've been welding for a few months on a TIG, and have been trying to get my beads to have that gold heat tint that all the kids think is cool these days.This is just decorative stuff at the moment, so I'm not really concerned about strength.The metal is SCH10 SS butt weld fittings. I can weld it just fine (fine enough for me, anyway) but my it's only gold at the end of the weld, when there is shielding gas. The rest of the bead is what I would call grey, but possibly silver.Now, from what I read on this forum, that means that the temperature of the bead was too hot when exposed to plain air.For reference:Stainless TIGSS colorInitially I used a 1/16" 2% Thor, medium gas lense, and #7 nozzle. This felt a little small to me so I went to a 3/32 tungsten, everything else the same. I would say that I can get a much better bead with the 3/32, but still no color.I tried moving faster, but that didn't work. I tried as little heat as possible, and that really didn't work. From a few threads here, the key is to keep the arc as short as possible and move quickly--but also that a larger nozzle will help keep the bead under argon long enough. So, I'm guessing my nozzle is too small.I've ordered a set of assorted cup sizes, and also a larger gas lense. But I have some questions in the mean time. How does one get that tint? Are the other colors (blue, purple, etc.) really that bad?From the videos I've looked at online (For Example: ), I'm moving as fast or faster with a smaller arc (as far as I can tell).
Reply:yeah man, it's all about gas coverage... on small tubing as you go around the diameter it's real easy to get ahead of the heat zone... I now use a very large 1" cup with a gas lens & LOTS of argon flow, only way I can get that look. large gas lens will need a lot of argon flow but when you're flowing enough you'll get the results your aftermiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:My understanding is the coloration you see is oxygen combining with some of the elements at the surface.  Straw, or gold, is the lightest amount of contaimination followed by salmon color (pink) and blue.I'm not sure how thick schedule 10, but if you have a very close fitup, and you use just enough heat to fuse the metal together without filler, what color do you get then?  Should be gold.  If not, there is something else wrong.  I'd start looking for gas leaks (air getting in) and if I couldn't find any, I'd swap the bottle of argon.If you are getting the nice gold color and only losing it when you add more heat, you need to back purge the weld.  If you have to add filler - your gaps are too large and you will have contamination on the back side - again, you need to protect the backside.   Back purge with argon (2nd bottle plus second regulator + hose or dual output regulator) or use something like solar flux (small can about $50).Just to recap, shiny silver is the ideal color.  From OK to Bad....  Straw, Salmon, blue, dull gray, dark gray even rust.For me, best results, 6x volume for back purge (purge at 15 cfh and then turn it down to 5cfh), 2 second pre-flow before I strike the arc.  When I finish the weld (stop the arc) I actually back up a little, try to direct the gas flow on to as much of the weld as possible.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:yeah, always a good idea to test your setup by just heating one spot & then letting it cool with gas coverage to make sure your gas & it's delivery is good. with this test it should be shiny silver only with no coloration. I once had a bad argon tank & this was the only way I could tell...  you also may need a good bit of post flow to not have it turn blue when the gas flow ends... I can run up to 30 seconds post flow on schedule 10 when really burning in for full pen. that's a lot, but much less & I don't get the same results... to get really nice stainless welds your going to need to use a lot of argon, between purging, higher flow for a larger gas lens & then long post flows...miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:Just to add:You might want to look at this page:http://aquasolwelding.blogspot.com/There is a picture with various levels of oxygen contamination.  Note that when there is zero oxygen, the color is bright silver.There is even a picture of what happens if you have a full penetration weld with no shielding at all.  The back side looks all rough (I think its called sugaring).  The top sides of welds can often be polished out, the inside of a tube is much harder.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:i been welding stainless for the last 7 years now going on 8...not as long as some other people on the forum....but one thing that i have learned about welding stainless and getting the NICE GOLD Blue. color is that its all about angle. and the hard thing about welding pipe it to keep the same angle 45 degrees roughly all the way around the pipe. it take a very steady hand and alot of dexterity. it might be good to focus on small sections at a time to keep the same angle and go from there till your able to do longer sections i guess depending on how big the pipe you welding is. try welding some "T" joints for practice. after i said all the. this question poped in my head:....whats the wall thinkness of the pipe you welding?
Reply:I agree with that. Angle is just as important as coverage. I was welding some plates inside of a 6" ID pipe and I was getting spotty coloring from pink to silver all due to angle.If you are welding for looks and not strength then fusing will almost always create a better color.
Reply:I guess your right because sometimes even with really good coverage I still get some pink, think I drop angle too far back from 45*. also when the angle drops off that's when the cup touches the pipe & cuts off gas flow to the tail of the weld a bit, giving the blueish tint from the shielding being cut off... all adds up to a pretty rainbow  as been's said, if you had perfect coverage you'd have no color, adequate coverage is a bit rainbow & dull grey is just not enough coverage at all...Last edited by turbocad6; 10-10-2011 at 11:28 PM.miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:Suprised nobody's mentioned it yet, but you're gonna need some preflow (a few seconds) to achieve the look you're after. If you don't have a preflow setting on your machine then before you start welding just tap the trigger/pedal to activate the post flow and use that.Last edited by Baila La Pinza; 10-11-2011 at 04:44 AM.
Reply:"A method of checking temperature is by the temper colors: A given temperature will leave a distinct color corresponding to that temperature.."Temperature C     And          Color                  204.4                     Faint Straw    226                       Straw    246.1                     Deep Straw    282                       Bronze                           Peacock    590                       Full Blue    640                       Light BlueSemper FiJesus may have been a Carpenter, but his dad was a Millwright" A grinder and a can of paint, will make a welder what he aint' "I've done so much, with so little, for so long, that now I can do anything with nothing!
Reply:Originally Posted by TIGger305after i said all the. this question poped in my head:....whats the wall thinkness of the pipe you welding?
Reply:ok so just under an 1/8 thick. ......what size filler are you using?..........sometime using thick filler will casue a gray color because of the heat u need to melt the filler is alot more then u need to melt the pipe so oxidation occurs. this is just my 2cents tho. try using 1/16 filler if ur not already....
Reply:The color is a indicator that the heat is set good and the "color" is the metal temper.As I posted above. Peacock shows at 282 Celsius or 540 fahrenheit.Also, one thing that effects temper color is the alloys in the metal. Sometimes you get the color and sometimes you may not.Besides, it's not something I leave for the customer as I wire brush it back to silver.Really it's more about weld quality then color, that's what crayons are for If you are getting grapes/sugar on the backside, you definitely need to back purge.If you just want color, try playing with the heat and maybe less gas. Also adjust travel speed.Last edited by skelley521; 10-11-2011 at 06:47 PM.Semper FiJesus may have been a Carpenter, but his dad was a Millwright" A grinder and a can of paint, will make a welder what he aint' "I've done so much, with so little, for so long, that now I can do anything with nothing!
Reply:Originally Posted by Cr-6.It's pretty much gapless--and I do get good color when I just tack or fuse the ends without any filler [I forgot about that!]. However, they are tapered so it looks a little odd without filler. I'd like to learn how to do it with filler anyhow. I'm going to pick up my larger nozzle and supplies and give it a go.I'm using 13CFH on the medium lense and #7. I tried up to 20CFH with no real change (except wasting gas). I will have to up the gas I imagine with the larger one. I'll play with it.
Reply:A final comment.  It seems from what I've been reading that the color of the heat tint depends on many things.  Type of stainless, temperature and oxygen content during welding.  The general concensus seems to be that heat tint up to and including blue is acceptable so long as the welded joint is not subject to elevated temperatures.  One article called out 100C as the line.   I think that color vs. heat chart might be for free air."The table below represents the temper colours that are likely to form on stainless steel type 1.4301 (AISI 304) if heated in air.THIS INFORMATION MUST BE USED WITH CARE WHEN INTREPETING THE HINT TINT COLOURS OBSERVED ON STAINLESS STEEL SURFACES AS THE HEATING CONDITIONS ARE NOT SPECIFIED.Colour Formed Approx Temperature Cpale yellow 290straw yellow 340dark yellow 370brown 390purple brown 420dark purple 450blue 540dark blue 600"Taken from:http://www.bssa.org.uk/topics.php?article=140Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Typed a reply last night but it didn't seem to take.  Didn't have the time/energy to retype.First off, it would appear that some of our posters must work for the gas company (will discuss later) and others have done some homework but haven't really done much SS welding.With regards to gas flow, a flowrate of 15-18 CFH should be more than adequate for the weld the OP is doing.  Higher flow rates are just wasting gas and setting up possible turbulance.  Any postflow over 1sec/10 welding amps is wasting time/gas.  30 seconds is "really wasting gas".  Folks, we're talking about SS here.  We're not talking about titanium where the use of a trailing shield (or chamber) is a necessity.Think about it.  If you're doing a proper SS weld, you're moving at a rate where the previously applied bead is going "out of the shielding gas" in less time than you've got your postflow set (using the 1 sec/10 A welding current).The grey bead the OP describes is most likely due to his "cooking the filler".  This is the result of either moving too slow or using too many amps.  The resulting bead, even if polished out with say a scotch-brite rolec disc, has lost some of it's corrosion resistance.I'm still not understanding a couple of the comments regarding the angle of the torch.  Does the poster who mentioned 45 deg mean 45 deg to the horizontal and 45 deg to the vertical (on a circumference weld--Sch 10 pipe)?  Surely he doesn't mean he recommends a 45 deg "angle of attack" with the torch.  Then again, maybe he does because that's about the only way I can see how he would be hitting the bead with the trailing edge of his cup (even with a 1" cup).  Using this drastic an angle of attack, you're pushing way too much heat ahead of the weld.The OP mentioned what tungsten size, cup size, filler, etc he was using.  What he didn't mention was the amps he was set at and whether he was using any pulse.Over the years, I've welded a "fair amount" of SS handrails (3/4"-1 1/2") on boats.  I'd say the most important elements of a good SS weld are proper amps, proper travel speed, and proper arc length.  Weld SS too slow or too hot and you're going to cook the filler.I'd recommend the OP practice his SS welding on filet welds on flat plate until he gets those above factors down pat.  The flat plate (vs the pipe/tube) will enable you to look at the heat pattern on the backside of the weld.  That is a good indicator of consistency.Not sure what the OP is joining his Sch 10 pipe to, but if I was doing this job, I'd set up with a gas lens, a 7-8 cup, 1/16" tungsten, 1/16" filler and set my welder to 100A.  Not going to need it all, but will get a quick puddle.  Maintaining a short arc with SS is nearly as important as the torch angle of attack (which should be about 70-75 deg).Went back and reread the OP's original post.  Caught that he was "butt welding" the tube.  If that is the case, I don't see where 45 deg should even come into the discussion with regard to torch angle.  The 45 deg I was talking about was for a filet weld where the torch is held at an equal angle between the horz and vert.  For the butt weld the torch should be held at 90 deg to the tubing with a 70-75 deg angle of attack (how much the torch is laid back).Since the OP didn't mention the machine he's using, I'm assuming he doesn't have a pulse capability.  If he does, once he gets the basics down pat, if he'll come back we may be able to throw him a couple of tips for using pulse that will further enhance his bead appearance.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Thanks for the advice everyone. Originally Posted by SundownIIITyped a reply last night but it didn't seem to take.  Didn't have the time/energy to retype.First off, it would appear that some of our posters must work for the gas company (will discuss later) and others have done some homework but haven't really done much SS welding.With regards to gas flow, a flowrate of 15-18 CFH should be more than adequate for the weld the OP is doing.  Higher flow rates are just wasting gas and setting up possible turbulance.  Any postflow over 1sec/10 welding amps is wasting time/gas.  30 seconds is "really wasting gas".  Folks, we're talking about SS here.  We're not talking about titanium where the use of a trailing shield (or chamber) is a necessity.
Reply:Cr-6.Couple things.Don't think you need a "bigger cup".  I use a WP20 series torch (or a 9 air cooled).  The biggest standard cup for a gas lens on the 20 is a 8 (1/2").  Plenty big.You may, next time you're at the LWS, pick up a # of .045 filler and give it a try.The 1/16" tungsten is plenty big for the welding you're doing on DC."Protecting" the back side of a SS butt weld is always recommended.  I use quite a bit of Solar Flux on the boat rails because I can't always get a purge on an existing rail setup.  Where the backside will never be exposed (visible), the solar flux works great and is more convenient than purging.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Well, I setup a purge and I think that is the solution. I can get much better tint with the purge. I'm guessing that the oxidation on the other side has, being a reaction, a heating effect. The HAZ surrounding the welds is much smaller than on some pieces were I ran no purge.I'm using a 5 CFH purge, 15CFH torch, #10 cup, large gas lense, and 3/32" tungsten. I broke my 1/16" gas lense, so I have to wait for my next order to come in before I can use some smaller tungsten. The 3/32 really feels a bit large, but not overkill.I would add pictures if I could figure out how. Maybe later.