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Miller-style MIG Aluminum Welding

Miller Aluminum Welding

The video below is from Miller’s large collection of welding YouTube videos. Be sure to make use of the invaluable tips on welding equipment, technique, and more on aluminum welding. As always, I’ve provided a transcript below the video. Enjoy!

When you weld aluminum, you’re dealing with a much softer metal. Because of this, you’ll need some special equipment and follow different procedures. Because of its softness, aluminum wire is difficult to push through a standard MIG gun – that’s why we recommend the use of a spool gun. This reduces the distance the wire has to travel. You can also use a push-pull gun as well but only on the Miller 252.

For aluminum welding, you will need to use 100% argon shielding gas.

Connect the weld cable from the spool gun to the positive stud in the weld compartment.

To install the wire into the spool gun:

  • remove the spool canister cover
  • take off the contact tip
  • unwind 6-8 inches of the wire, clip off the end and straighten it
  • then, using the guides, thread the wire through the gun
  • then replace the canister cover, close the tension arm, and reinstall the correct contact tip to match the wire diameter
  • then install the nozzle

To test the drive rule tension, feed wire onto an insulated surface. If it is too loose, you’ll get results like this. Increase your wire tension until a consistent wire speed feed is achieved, giving you this result.

Now, when correctly set up, the tip on your spool gun will be recessed 1/8th inch.

And before we start welding, here’s a couple of tips to make life easier:

  • We recommend that you weld only on 14-gage or thicker aluminum using the MIG process. If the aluminum is thinner, you may burn through the work piece.
  • Again, clean pieces weld the best. Remove the oxides with a stainless steel brush. A separate brush should be used for cleaning aluminum.
  • Using the right wire is critical. Contact your local distributor for assistance in selecting the right wire for the job.

Now we’re ready to weld.

Use a 10-15 degree push angle when welding aluminum. This angle will clean the material by allowing the shielding gas to get in front of the weld puddle. If you use a pull or drag angle, the weld will appear black or sooty.

Keep the nozzle about 3-quarters inch from the work surface.  Any closer and you may get burn-back or other feeding problems.

Set your voltage and wire speed at the recommended setting from the parameter chart and

fine-tune as you need. These settings should produce a spray arc transfer. This will sound more like hissing. If the settings are correct, the amount of smoke and spatter will be reduced.

Try to avoid large weave beads on aluminum. A straight weld or a short-stitch motion will get better results.

Aluminum welding is more difficult than steel, and the more practice you get the greater your skill level.

For more tips on welding with aluminum, go to the manuals, training, and more section of this CD.




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