Stainless welding questions

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After searching i wasnt really able to find an answer to my question. I just recently got a tig welder and I want to practice welding stainless. When I weld I have a tendency to get my face just about in the weld puddle ha, thats just how I weld. Do you fellas that weld a lot of stainless wear any type of respitory protection? I keep hearing about the hexavalent chromium from welding stainless. Should I be concerned? I usually try to hold my breath as much as possible when welding anything even though I really like the smell of clean mild steel while running a bead haha. Another question about stainless is all this talk about sugaring? From what Ive gathered it only happens when not backpurging pipe welds? Is this true? If i were to weld some stainless flat stock to practice would I sugar the underside? Is there a way to avoid it? Aside from harboring bacteria and stuff for the food industry what is the bad part about sugaring? Is it just aesthetic or is there some kind of bad byproduct? Someone please school me on this stuff. I would really love to get proficient in welding stainless.Thanks in advance!
Reply:Sugaring is the "break down" of the stainless due to exposure to the air. It happens any time red hot stainless come in contact with air. If you are welding thin sheet and the heat goes all the way to the back, it will sugar unless protected or back purged.Besides being ugly, you loose part of the stainless qualities of the material as well as creating places for bacteria in food service stuff.Depending on what you are doing there are ways to avoid back purging for practice. If the stainless is tight up against a backing you restrict the amount of air that can reach the hot weld. They also sell solar flux that you paint on the joint to protect it from sugaring if you can't back gas.I'm never going to tell someone a respirator isn't a good idea. If you plan to do a lot of stainless and are that close, investing in one wouldn't be a bad idea. You only get one set of lungs usually..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:In the shop I work in we have to have a vent approx. 12" from the work piece.  If I'm in the field there is usually enough airflow to keep you OK.  Unless I'm down in a confined space like a tank then I will wear a respirator under my hood.  At home I usually have plenty of ventilation so I'm not worried about it.The only way you will sugar the piece of flatbar is if you are melting through to the other side.  Usually means way to hot. If you are welding pipe then yes use an argon backing purge.
Reply:We use 3M P100 disposable respirators that are OSHA compliant, and draw the fumes away with table fans while tigging. P95 masks are not compliant. Although Tig welding developing significant amounts of hex6 chromium is disputable, we don't want problems from OSHA.DWS said it the way I would about sugaring. Purging is one way to prevent it, air displacement backing blocks are another. You can even burn in against the blocks to control your penetration. We call them a backing shoe. Sometimes the backing shoe need purge vents if the fit is questionable. You will see on some groove weld cert test fixtures that purging is introduced to the backside.And like Murphy's Law said sugaring mostly happens with melt through, however most parts that are radiographs will be purged regardless. Any anomoly that arises on the film will trigger rejection if the root cause can't be determined.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:I think Hex chrome exposure from TIG welding is less of an issue than using stainless stick or fluxcore welding products(including hardfacing products).  But I'm with the others, there's nothing wrong with wearing a respirator.  Make sure you have good ventilation while cutting or grinding also.  If you use a plasma cutter, be aware of the ventilation.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Thanks for the responses fellas.Im actually wondering if me being worried about chromium is just me being paranoid or is it a legitimate concern. I tend to be paranoid with stuff like this. I guess what I was trying to gauge is how many guys will just throw on their helmet and run a bead and not think about it. I always overthink stuff like that which isnt necessarily a bad thing, just sometimes I have to be brought back to reality with it. I usually wear a respirator when grinding, but never really when welding. Like I said I just try to hold my breath as much as possible and while welding or grinding, ill have the garage doors open for ventilation.Anyone have any tips for me regarding tigging stainless and aluminum? I watch Jodys videos and do a ton of reading, but one could never have too much knowledge.
Reply:Hello Threadkiller, hex-chrome is something to be concerned about. Tig welding of stainless produces the least exposure of any welding process designed for stainless short of maybe spot welding or robotic applications. The thermal cutting and grinding of stainless is the worst. Thermal cutting can include: carbon arc, plasma cutting, and laser, laser being the least contributor of the cutting processes. Grinding and abrasive cutting of stainless is something to concern yourself with as levels of air-borne particles is high and that is where the danger is. So certainly the use of a respirator around stainless steel is a really good idea. My personal thoughts on this go along with smoking, there are folks who smoke their whole life and don't get lung cancer, there are others that do. Hex-chrome is a similar scenario. So I believe that it is a personal choice for now, yet in the future that may change as well. Best regards, Allanaevald
Reply:Originally Posted by ThreadkillerThanks for the responses fellas.Im actually wondering if me being worried about chromium is just me being paranoid or is it a legitimate concern. I tend to be paranoid with stuff like this. I guess what I was trying to gauge is how many guys will just throw on their helmet and run a bead and not think about it. I always overthink stuff like that which isnt necessarily a bad thing, just sometimes I have to be brought back to reality with it. I usually wear a respirator when grinding, but never really when welding. Like I said I just try to hold my breath as much as possible and while welding or grinding, ill have the garage doors open for ventilation.Anyone have any tips for me regarding tigging stainless and aluminum? I watch Jodys videos and do a ton of reading, but one could never have too much knowledge.
Reply:Originally Posted by aevaldHello Threadkiller, hex-chrome is something to be concerned about. Tig welding of stainless produces the least exposure of any welding process designed for stainless short of maybe spot welding or robotic applications. The thermal cutting and grinding of stainless is the worst. Thermal cutting can include: carbon arc, plasma cutting, and laser, laser being the least contributor of the cutting processes. Grinding and abrasive cutting of stainless is something to concern yourself with as levels of air-borne particles is high and that is where the danger is. So certainly the use of a respirator around stainless steel is a really good idea. My personal thoughts on this go along with smoking, there are folks who smoke their whole life and don't get lung cancer, there are others that do. Hex-chrome is a similar scenario. So I believe that it is a personal choice for now, yet in the future that may change as well. Best regards, Allan