help with stainless

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ok im getting mixed results and dont know why... maybe its me maybe its the metal. im not getting colorful welds mine are just grey in color   100 %argon  this was welding on a exhuast off of a can am commander and a stainless y pipe for camaro.  it looked good just no color to the welds.. didnt try to brush them afterwards
Reply:check this out- match up materials. sometimes stainless welds don't look too great until you brush them.http://www.esabna.com/literature/Pla...TIG/tig5_2.pdf
Reply:There are several reasons why this could happen. The most likely is that you're running too many amps, and putting too much heat into the piece. That's probably the number one concern. Next, you not be getting adequate shielding... First thing I'd do is turn down the heat a bit.Proud to support Reliable Sheet Metal Works, in Fullerton, CA.Full service sheet metal fabrication serving Orange County since 1926.http://www.reliablesheetmetal.com
Reply:When tig welding stainless pipe/tubing you need to use shielding on the inside of the pipe to prevent oxidation of the weld area. Are you using internal shielding?JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Thin material is harder to weld  and requires a touch, Stainless is NOT the easiest material to weld and doesn't give you a second chance.......Set up is everythingPractice on thicker material till you get the hang of it............Last edited by B_C; 11-22-2011 at 10:23 PM.  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by snoeproeWhen tig welding stainless pipe/tubing you need to use shielding on the inside of the pipe to prevent oxidation of the weld area. Are you using internal shielding?
Reply:Most likely culprit is too high of a heat input, the material doesnt have time to cool down enough before the gas shielding moves on.  It could also be a bad connection in your torch line somewhere, letting air get into the gas as it flows from the cyl.  Do a pressure check on the lines to make sure.  The other possibility that I have seen personally, though I hate to keep pointing it out, is a bad gas mix.  I have had it where I put on a brand new tank (took the plastic off the valve) it looks ok while welding however upon completion the entire weld bead is a nice dull grey.  Changed to another new tank, problem went away completely.Have we all gone mad?
Reply:Stainless will form a colorful oxide layer with the color depending on at what temperature the metal is when it comes int o contact with the atmosphere. It has everything to do with keeping shielding gas on the part until it cools down enough. You might wanna try a bigger cup (gas lens), more flow, or even a trailing shield for small diameter tube.It took me a couple hours of tinkering to figure out how to make gay rainbow welds.Welding/Fab Pics: www.UtahWeld.com
Reply:Originally Posted by MikeGyverStainless will form a colorful oxide layer with the color depending on at what temperature the metal is when it comes int o contact with the atmosphere. It has everything to do with keeping shielding gas on the part until it cools down enough. You might wanna try a bigger cup (gas lens), more flow, or even a trailing shield for small diameter tube.It took me a couple hours of tinkering to figure out how to make gay rainbow welds.
Reply:Ha, gay rainbow welds.I need to work on this too. I don't do much stainless tig but I want to tinker with appearance and backpurging.IW Local 580 NY, NY
Reply:Great thread! I'm having problems with my stainless beads not coming out grey also. The very start and end of each weld looks ok, but most of the bead is fine. If I use less heat, I can't melt the metal...  So it seems like too much heat not enough shielder gas. If I just run the torch over the metal and add no filler, it looks fine with a nice blue like haze. I'm thinking the filler rod and plate I am practicing on are not the same material?Thanks in advance. Wayne
Reply:90% of the issue to keeping the color is purging gas.....use alot.....ALOT, a large cup with gas diffuser works real well. Back purge is the key, if you want the color....I never cared that much about it. If you do any open groove welding on stainless you will have to back purge as was said earlier in the posts. The cooloer you can weld it the better it is, perfect fusion......A young green pipe welder asked an old salt one day...How can I make the weld on the bottom of the pipe look like the top.......The old salt replied....Screw up the top......
Reply:People throw around the term 'too much heat' too much. It obviously takes a certain amount of heat to just maintain a normal, not excessive, sized puddle, and that much heat is just fine. The less heat you put into it, the less trailing shield you'll need to get colorful welds, so keeping heat under control is helpful.Again, it's the shielding gas (unless you're 'welding' way the hell too hot). If you're noticing the last 1/2" of your weld is colorful due to the postflow, then it's telling you the rest of the weld didn't have coverage long enough while it was cooling.Here's a chart showing degrees Celcius and oxide color.Last edited by MikeGyver; 11-23-2011 at 11:19 PM.Welding/Fab Pics: www.UtahWeld.com
Reply:Great thread. Do you guys mind providing some feedback? I have been practicing on stainless tubing and working on my backpurge setup. This is 1.125" OD x 0.030" wall 410 tubing. #7 cup and gas lens. I use a heat sink inside the open ended tube to keep distortion down. The heat sink is also plumbed for purge gas. So with the heat sink, I turn the amps up a bit and ease back on the pedal once I get a puddle going. I have been trying to move fast to keep the heat down.Here are a few different pieces (1.5" OD and 1.125" OD, both 0.030" wall) and some of the results I've been getting inside. Sorry about the horrible crater at the end of the bead.Aside from the crater, any other tips? Does the melt through inside the 1.5" tube indicate too much heat or moving too slowly? I haven't been getting nearly as much melt through with 4130, but I know the stainless doesn't conduct the heat as well. Thanks in advance!
Reply:Hi,new here.I always push weld ss tubing to preheat.Use a ceriated tungsten ground to a point with a small flat spot on the end,and it's gotta be really clean.Where I live 100% argon,I would'nt bet on it.I got a bottle of acet. last week I'd swear is half propane.I do a lot of ss tubing,been letting it cool slowly,lots of postflow.Been having pretty good luck.
Reply:Originally Posted by zankGreat thread. Do you guys mind providing some feedback? I have been practicing on stainless tubing and working on my backpurge setup. This is 1.125" OD x 0.030" wall 410 tubing. #7 cup and gas lens. I use a heat sink inside the open ended tube to keep distortion down. The heat sink is also plumbed for purge gas. So with the heat sink, I turn the amps up a bit and ease back on the pedal once I get a puddle going. I have been trying to move fast to keep the heat down.Here are a few different pieces (1.5" OD and 1.125" OD, both 0.030" wall) and some of the results I've been getting inside. Sorry about the horrible crater at the end of the bead.Aside from the crater, any other tips? Does the melt through inside the 1.5" tube indicate too much heat or moving too slowly? I haven't been getting nearly as much melt through with 4130, but I know the stainless doesn't conduct the heat as well. Thanks in advance!
Reply:Originally Posted by Showdog75I think your progressing rather nicely. That melt through is just good penetration and shows you have a good purge as there is no sugaring.