I have been practicing welding with my MIG. I think I am getting good welds. I beat on them, and they don't seem to break.
What I am bugged about is the "fit and finish" of the process. I see sites that show different welds, and they look great. For example I saw a Ducati motorcycle frame that claimed to be MIG welded, and it was superb....apparently no grinding or other cleanup.
Is it just a lack of skill on my part, or is there always a ton of cleanup, grinding, etc...to get a nice looking fit and finish?
Remember that a lot of those welds are done by robots. I can get beyootiful welds with my MIG, and then, a real groaner. These are identical welds like repetitious welds when welding wrought iron.
There are some things that robotic welding has over humans. They travel at an exact speed. On starting a weld, they may have a pause time, or may even be moving before the arc is struck. When everything is right, higher heat can be used with less chance of burnthrough. Rule is that the better a weldor is, the higher heat he can run on the same materials with the same rod.
But I do agree with you. I see some welds of manufactured goods, and wonder, "How'd they do that?"
Yeah, don't get discouraged.. I've found that, when acquiring a new skill, there's a series of peaks and valleys (if you will).. You'll do good, and then maybe not so good, keep going and you're doing better. It's the part of the brain that learns stuff like walking fighting for control with the conscious part.. Stick with it, that's all you can do. Consistency is the ticket, watch for what you do that's right and try to knock off what's wrong.
Listen to the arc, that tells you much in addition to what you see. Watch your stickout, that's important- especially if the machine isn't particularly forgiving.
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
What you lack is experience. You shouldn't have to grind the weld itself. If you use straight CO2 you might have to grind a little spatter. Using 75/25 Argon/CO2 you should have little or no cleanup.
A lot of people think MIG welds should look like the "stack of nickels" characteristic of stick welding. Robots can be programmed with a slight whipping action but I have read that doing this manually may result in a lack of root fusion. Maybe the robots are creating a nice convex bead with freeze lines. It seems like even a perfect straight manual MIG weld does not have the aesthetic appeal of a nicely done stick bead.
A lot of people who don't know anything about welding think that if a weld looks like a stack of nickels, it is a good weld. The "stack of nickels", more commonly called "stack of dimes" is achieved using a 6010 electrode with electrode positive, and a whipping action. A molten puddle is established, then the electrode whipped out of it long enough for the puddle, which looks like a human blood corpuscle to harden. Then the process is repeated. The welds are pretty, but not that sound, as the fusion is interrupted by the heating/cooling cycle.
Robots can be programmed with a slight
Bingo!
Maybe the robots are creating a nice convex bead with
That depends on the rod, and the base material. Thick steel and 7018 rod gives an outstanding appearing weld, and a very strong one. It is done with no whipping action.
I am ass-u-ming that you are referring to my comments in the previous post of :
I can tell you don't do a lot of welding.
Steve
You, see, when you post the conversation, it is easier to follow than just taking one line of a conversation and spewing, which you did, and which makes no sense to anyone reading one line of spew.
Now, to your point about welding. MIG (GMAW - Gas Metal Arc Welding - is the technical name, but you knew that, right?) welding can be pretty, and even, and not need cleanup. But, if there is ANY contamination from oil, dirt, paint, poor fitup, infiltration of ambient air from the rear of the weld, or interruption of the shielding gas by air currents, there can be porosity in the weld that needs to be dressed up. (ground)
You seem to slam others for not being experienced, yet in your own statements exhibit that you lack the experience needed to state the obvious regarding porosity in MIG welds.
Steve, who has been welding since 1974, topside, underwater, and in the dark. ;-)
Not to mention that once programmed, in general, curve following is as easy as doing straight welds. Few weldors can go at the same speed on tube welds as straight.
I once went to a welding convention in Las Vegas. It was absolutely awesome. More there than your brain could take in. One display had a cart that was tack welded. A robotic welder was doing welding movements, but without an arc. The positioner would twist and roll the cart so that it would move to the next weld when the robot was done. So, you had two movements there. One of the torch head, and the other of the positioner. Automated welding in conjunction with CNC and CAD/CAM programs is really impressive.
Practice! Try experimenting with your angle of approach, using a "push" rather than a "drag" approach. Set the heat and wire feed rate so it "sounds right", then control rate of deposition by varying rate of progress.
Push or pull. Above centerline, below centerline, forward of center, behind center. That is mathematically a lot of permutations.
Everything you do to vary the angles, speed, movement, and aim of a welding torch will give you a different result. The thing you want is repeatability so that you can make a lot of welds that look the same. You need to weld a lot to clearly understand how the difference in the position of the torch head during welding affects the final properties of the weld. And, whether you aim the wire at the root, or aim it on one side or the other and then let the molten pool wash onto the other piece has a great deal to do with the final outcome, too.
Not as simple as some people make it out to be. Every time some small variables changes infinitessimily (sp?), the whole thing changes.
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