|
|
Hey guys, i need alittle bit of help here. today at work I hopped on their old Miller Tig machine and tried welding some AL pieces for them. Unfortunately, things didn't go as planned!All the T.I.G machines I have used, had high frequency so you did not need to strike the tungsten to the base material. Well this machine i used for work today was one of those machines you had to make contact. ( I am confused because on the front panel, it does have an option for high frequency, Continuous, Off, or Beginning.)I am using 4043 filler rod, and i wouldn't even consider these beads. full of porosity and black crap. The filler metal wouldn't "drip" into the puddle, it would like slowly melt and still have some sort of puddy consistency( im trying my best to describe lol )I know how to lay a decent AL bead with gtaw, but this time it is much different, and much more uglier. I am taking a guess and thinking that while striking the tungsten to the base metal, I contaminate the Tungsten, thus producing god-awful beads. Should i be colder? Hotter?here are some pictures. i hope i dont sound like a COMPLETE moron
Reply:From looking at the pictures, the porosity & lack of fusion to the base metal, I would say the welds are contaminated & the base metal must be absolutely clean. Stainless Steel brush & wipe with a solvent like Acetone, then go to town. Probably wouldn't hurt wiping the filler rod with Acetone either.MarkI haven't always been a nurse........Craftsman 12"x36" LatheEnco G-30B MillHobart Handler 175Lincoln WeldandPower 225 AC/DC G-7 CV/CCAdd a Foot Pedal to a Harbor Freight Chicago Electric 165A DC TIG PapaLion's Gate Build
Reply:you could lay a small piece of copper ( pipe flattened or an old real penny)next to your item to start off ofcopper is less likely to stick to the tung.idealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:Looks to me that you had it set to DCEN if the pic of the machine is how you had it set for the welds shown. The welds look like a combination of lacking of gas or the wrong gas and DC Aluminum GTAW is more often than not done with AC and continuous HF. The machine pictured needs the HF to carry the arc through the dead time during the ac cycle.
Reply:gas is at about 15i will def try the cleaning with acetoneDCEN? Im running on AC with high frequency continuous ( alittle confused )
Reply:and the gas is 100% Argonthe adjuster with the black ball knob is the polarity control. the lever is in the middle, which is ACthe 90degree bend bare metal adjuster, below the black ball knob, is the amperage range.
Reply:Is there any preheating going on? That looks to be a large piece.It looks like there is no penetration, just the wads of filler laying on the surface of whatever it is you're trying to weld.BTW, if you size your pics to around 800X600 they won't get cropped by the forum software.Rex
Reply:you might want to check the spark gap was just a thought or it may need to be cleanedidealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:Same as everyone else says... I would suggest cleaning the base metal better and going hotter.Try cleaning the base metal with acetone, scrubbing it with stainless brush, wipe down filler rod with acetone. Use more heat, it doesn't look like you got any penetration at all. My understanding is the rule is start off around 1 amp per .001 thickness so if that's 1/8" then try around 125 to 140 A. You should be able to get the base metal to puddle up before you start adding any filler. Use AC current, I saw some mention of DC in the thread, but I don't see any cleaning around the edge of the weld, so try with AC. Also might try to pre-heat the piece using mapp gas or an OA setup, or at least run the torch across it without filler. Also the base material could be giving you trouble, do you know what it is (6061, etc)? Good luck.BTW that old machine looks like a beast!"hope for the best, prepare for the worst"Some of my equipment:Miller Millermatic 140Miller Syncrowave 200Lincoln PowerMIG 215
Reply:I don't see any "cleaned zone" running along the weld that is usually there from AC welding on Aluminium.Stupid question, but are you 100% sure it's ali your are welding and not stainless or something? Don't mean to sound patronising.Good luck.Cheers, Ryan Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. - Albert Einstein
Reply:Looks like what happens when you use aluminum filler on magnesium.Peter |
|
发表于 2021-8-31 23:42:53