TIG Tungsten Angle

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Say your going to TIG weld a flat position square butt joint on 1/4" thick 304 stainless steel.  Your not going to add any filler, simply fuse the joint and get the best penetration you can.  You are limited by your puny power supply to 100 amps.The only variable you can change is the grind angle on the tungsten electrode, everything else, from travel speed to gas type is fixed.So, in your experience or gut feeling, which of the following will give the best penetration, and do you have a reason why?A.  Really sharp = 10 - 30 degree included angle.orB.  Really blunt = 90 - 120 degree included angle.Last edited by pulser; 10-06-2006 at 03:20 PM.
Reply:really really really sharp...about a 20 degree angle will work......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:point yes travel speed on Tig? we on a timer? i got lost there ya got to speed up or slow down  some way working temp of the metal, im welding travel or speed is why we do Tig    MORE CONTROL
Reply:If you go too sharp and too hot, you will burn the tungsten off into the weld...but go as sharp and hot as you can.
Reply:OK, didn't get very many bites on this fly, and yeh I suspect 99% of the welders out there will tell you that a sharp tungsten gives the most penetration.  Well welding can be a funny thing, there are a bunch of variables that affect TIG weld shape and actual results may not always follow theory, BUT THE THEORY IS, A BLUNT TUNGSTEN WILL IMPROVE PENETRATION OVER A SHARP TUNGSTEN.Blasphemy you say, no way, I always use a sharp tungsten!  Well, have you ever tried a blunt end prep, say 75 to 120 degrees?  Probably not, because we are all first shown how to grind the tungsten to a point, the arc starts easy, and it works just fine.  For most all welding who cares, grind it sharp, I agree.  I would just like to point out the possibility that a blunt tungsten may actually improve penetration, and a reason why.Take a look at what Pro-Fusion says about electrode tip geometry:http://www.pro-fusiononline.com/tungsten/geometry.htmIn theory, the arc tends to come off the sides of the conical electrode, and since the sides of a sharp electrode are more perpendicular to the base metal than the blunt electrode, the arc is broader and less concentrated, giving less penetration.This attached photo, copied from the AWS Welding Handbook, shows what I'm talking about.  Note the welds shown are spot welds, so we don't know what the effect of traveling would have on these welds.  Also, this is a topic for later, but we don't know the chemistry of this base metal (particularly Sulfur) and this can have a substantial effect on fluid flow and weld shape.http://i94.photobucket.com/albums/l1...trodeAngle.jpgWadda u think?
Reply:Funny you should mention this ,Just yesterday I was fusing 50mm 1.6 wall 316 to a 6mm 316 base plate and this job specified 2 posts with a 3mm wall.I found that a 45 deg. angle worked much better on the thicker wall.I was using a PT 185 and a hand amp controller so not  sure what amps I was using.Can you or have you tried the same angle but with a thicker electrode? (just guessing here)
Reply:Originally Posted by pulserBUT THE THEORY IS, A BLUNT TUNGSTEN WILL IMPROVE PENETRATION OVER A SHARP TUNGSTEN.Take a look at what Pro-Fusion says about electrode tip geometryWadda u think?
Reply:This was a carefully controlled study that explored the extremes of the process.  Of course there are logical reasons why you would not use a 15 degree or 180 degree grind.
Reply:Ok, you just lost me...What does a tungsten with a 180 degree grind look like?
Reply:I know it's bizzar, it's just a flat ended tungsten.  Of course there is probably no reason you would actually use it, but it was just one end of the spectrum for this study.  Look at the photo, it shows the 180 deg. tungsten and the arc kind of coming off to one side.
Reply:Originally Posted by pulserThis was a carefully controlled study that explored the extremes of the process.  Of course there are logical reasons why you would not use a 15 degree or 180 degree grind.
Reply:Originally Posted by Joe HOk, you just lost me...What does a tungsten with a 180 degree grind look like?
Reply:Originally Posted by EngloidI think it's the opposite of having it ground to a 0 degree angle.