Best aluminum settings

[srp]

After welding up more pop cans today, I came to the the conclusion that 10% EP with 250 hertz was the best setup with the tungsten ground on a very fine wheel. Also tried a fast pulse ( 300PPS to 500PPS ). The machine seems to pulse only on the DC half of the wave because it has more cleaning action on pulse. It did very good on both pulse and non pulse with not one burn through at those settings.

[jakeru]

I gotta say srp, you are making your 250EX do some impressive things. I don't think my super200P offers as good heat control on the low end as you have demonstrated the 250EX can provide with that popcan weld. The only way I have a chance of controlling can welding is to crank up the EP% AC balance to make the arc stabilize with less heat being inputted into the work. (And it doesn't work all that well; the arc is not very focused set like that, and it tends to wander all over.) Luckily I don't find myself needing to weld very many aluminum cans. I do feel like have great heat control in the range where I need it, at least. And oh by the way, the pulsing on the Super200P ceases to function at low amperages. I think the "background current" is a minimum current setting on it so if you throttle the output below that setting, no pulsing action no matter where you set the pulse control knobs. The fact the 250EX can pulse at a very low amp output range is impressive.

That said, I've been experimenting with varying the footpedal with each dip to change the profile of the built-up weld bead recently, and am still discovering some new "tricks." With some techniques and settings, I find that I can make the edges of the built up portion of the weld bead stick up abruptly, and then flatten the tops (kind of like stacking dimes) with another setting, I can make the tops concave, and with another, I can mound the whole weld bead up in a convex shape. (see picture example below.)

Here is the convex droplet (with footpedal modulation) example. (Compare it to the "flattened droplet top" example I attached in post 17, here; it is basically the same item, material, joint, and machine/gas settings, only with the footpedal now being modulated/synchronized to the filler rod adds)


I am still not sure if using the pedal with each filler rod ad may make the overall process that much more difficult to achieve perfect consistency though, or whether it might be helpful to have the extra control (as long as you're paying attention while putting down the bead.) I'm going to keep practicing it. It's funny how we get into these habits of doing things a certain and it just "seems right." Anyway, so far, I like the footpedal modulation technique very much, it seems to provide me more leeway as to how fast I need to move also. What I mean is, if my filler rod needs a bit more time to catch up feeding the rod, I just dwell at lower current setting a little longer, and there is no problem. With the more constant amperage technique, that might necessitate varying the pedal and kind of getting the rhythm thrown off, or breaking the arc and needing to restart (or else, get an inconsistently large puddle.) By the way it's not just about changing the footpedal, as much as it is changing the footpedal while also synchronizing the addition of the filler rod. For example, to get the convex shape, as I throttle the current back, I continue to add rod as I throttle it and the base of the convex shape freezes, and only the top of it remains liquid. You just do the same thing over and over and the beads are pretty consistent.

I suppose if I wanted I could try doing a sequence of bead profiles. EG: concave, flat, convex, concave, flat convex, etc. Just for fun, I think I will have to give that a try!

[jp2code]

Nice beads, Jake.What is the gold looking material, brass?