Hey guys, Ive been a lurker and hobby welder for some time now and recently got into TIG welding stainless (304) steel.
I, like many others, tended to have a few issues with achieving those lovely temper colours that we always see online. After much browsing of forums and Youtube I came up with a short list of tips and tricks (A few of them from this forum) that got my welds looking somewhat decent. Some are rather obvious now, but weren’t when I first started. Also, this is by no means a comprehensive guide, just what worked for me, so thought I would share it.
Setup:
Check your shielding gas flow rate is correct for the cup you are using. Often the flow numbers quoted are a rough guide. They don’t necessarily cover all scenarios, Eg: I’ve found when welding at the base of a Tee joint there is more than enough cover. However, if it’s an outside corner, I’ll need to up the flow a bit as the gas tend to wash away from the puddle. Don’t overdo it although, as too much flow will create turbulence and draw oxygen into the shielded region, ruining the weld.
Check your tungsten stick out. Avoid having it too far out as it will oxidise and contaminate your weld. If, for whatever reason you need that kind of stick out, use a gas lens and up your flow rate to compensate.
Grind a fresh point on your tungsten. When you put your torch down it can pick up all sorts of crud. I tend to freshen it up before each welding session. As for shape, to be perfectly honest, I haven’t noticed a difference in different point shapes. Either stainless isn’t as easily affected or I’m just not welding on a scale that it would become apparent.
Fabrication:
Avoid the need to use filler as it is another way of introducing contaminants into the weld. Try and get your parts to match up as perfectly as possible. If you can, clean up the mating surfaces on a belt sander and check that they are square and have little to no gap. If gaps are unavoidable see Method below.
Cleanliness:
When trying to achieve a clean weld, cleanliness is key (Who’d have thunk?). I prefer to use acetone when cleaning as it doesn’t leave a residue like thinners or petrol.
Wipe down your filler rod. You will be amazed at how dirty it is fresh out of the bag.
Once you have confirmed the fit of your parts (See Fabrication), thoroughly clean all of them with acetone. Any oils, including fingerprints will ruin the finish of the weld.
Check your gloves for oil and dirt. You don’t want to handle your freshly cleaned parts with the old gloves you use for grinding.
When you’ve finished grinding the tungsten, give it a wipe with some acetone on a cloth. You’ll want to remove any grinding dust or residue that may be on it.
Method:
Every time you add filler rod, avoid pulling it out of the shielding gas after dipping. If you do this, the red hot tip will oxidise. When you dip it again, the weld will be contaminated. When i first started, i found it easiest to use a larger cup than was necessary, thus giving me more room for error both with shielding the filler rod and the puddle. The downside being I went through quite a bit of gas.
Stainless does not like heat. Use as little heat as necessary to form and maintain the puddle. The more heat you put in, the more likely the metal is to oxidise, giving you a dull finish.If you are welding hollow sections and aren’t back purging, you’ll want the sugaring to just start forming on the inside. This way you can ensure are getting as much weld penetration as possible without overheating it. (Please note: This method is fine for cosmetic welds that don’t serve a structural purpose. These welds will tend to be more brittle and thus prone to fracture if loaded. When in doubt, back purge.)
Avoid welding in a breeze, whether it’s a fan or open window. Any wind will blow the shielding gas away from the puddle causing all sorts of issues. If I am going to weld, i will close the back garage door to avoid any cross ventilation forming a draft.
Lastly, practice, practice, practice. Cut yourself some coupons and practice welding them with various weld joints and orientations. As they say, practice makes perfect.
I, like many others, tended to have a few issues with achieving those lovely temper colours that we always see online. After much browsing of forums and Youtube I came up with a short list of tips and tricks (A few of them from this forum) that got my welds looking somewhat decent. Some are rather obvious now, but weren’t when I first started. Also, this is by no means a comprehensive guide, just what worked for me, so thought I would share it.
Setup:
Check your shielding gas flow rate is correct for the cup you are using. Often the flow numbers quoted are a rough guide. They don’t necessarily cover all scenarios, Eg: I’ve found when welding at the base of a Tee joint there is more than enough cover. However, if it’s an outside corner, I’ll need to up the flow a bit as the gas tend to wash away from the puddle. Don’t overdo it although, as too much flow will create turbulence and draw oxygen into the shielded region, ruining the weld.
Check your tungsten stick out. Avoid having it too far out as it will oxidise and contaminate your weld. If, for whatever reason you need that kind of stick out, use a gas lens and up your flow rate to compensate.
Grind a fresh point on your tungsten. When you put your torch down it can pick up all sorts of crud. I tend to freshen it up before each welding session. As for shape, to be perfectly honest, I haven’t noticed a difference in different point shapes. Either stainless isn’t as easily affected or I’m just not welding on a scale that it would become apparent.
Fabrication:
Avoid the need to use filler as it is another way of introducing contaminants into the weld. Try and get your parts to match up as perfectly as possible. If you can, clean up the mating surfaces on a belt sander and check that they are square and have little to no gap. If gaps are unavoidable see Method below.
Cleanliness:
When trying to achieve a clean weld, cleanliness is key (Who’d have thunk?). I prefer to use acetone when cleaning as it doesn’t leave a residue like thinners or petrol.
Wipe down your filler rod. You will be amazed at how dirty it is fresh out of the bag.
Once you have confirmed the fit of your parts (See Fabrication), thoroughly clean all of them with acetone. Any oils, including fingerprints will ruin the finish of the weld.
Check your gloves for oil and dirt. You don’t want to handle your freshly cleaned parts with the old gloves you use for grinding.
When you’ve finished grinding the tungsten, give it a wipe with some acetone on a cloth. You’ll want to remove any grinding dust or residue that may be on it.
Method:
Every time you add filler rod, avoid pulling it out of the shielding gas after dipping. If you do this, the red hot tip will oxidise. When you dip it again, the weld will be contaminated. When i first started, i found it easiest to use a larger cup than was necessary, thus giving me more room for error both with shielding the filler rod and the puddle. The downside being I went through quite a bit of gas.
Stainless does not like heat. Use as little heat as necessary to form and maintain the puddle. The more heat you put in, the more likely the metal is to oxidise, giving you a dull finish.If you are welding hollow sections and aren’t back purging, you’ll want the sugaring to just start forming on the inside. This way you can ensure are getting as much weld penetration as possible without overheating it. (Please note: This method is fine for cosmetic welds that don’t serve a structural purpose. These welds will tend to be more brittle and thus prone to fracture if loaded. When in doubt, back purge.)
Avoid welding in a breeze, whether it’s a fan or open window. Any wind will blow the shielding gas away from the puddle causing all sorts of issues. If I am going to weld, i will close the back garage door to avoid any cross ventilation forming a draft.
Lastly, practice, practice, practice. Cut yourself some coupons and practice welding them with various weld joints and orientations. As they say, practice makes perfect.
