stick welding aluminum with my Super250P
I'm sure that everyone with a stick welder, arc welder, SMAW welder, or DC TIG welder has wanted to weld aluminum at one time or another. The main problem with this is actually information, not technology. Most web pages and forum posts state that a MIG or AC TIG welder with argon shielding gas is required to weld aluminum, which is not accurate. What should be stated is that AC TIG is the slowest, cleanest, and most controllable way to weld aluminum, which makes it especially good for welding thin aluminum. MIG is much faster than AC TIG, but it is not nearly as controllable because you cannot melt the base metal without adding filler metal. MIG was designed for fast buildup and continuous welding and it is still relatively clean because of the shielding gas. Neither AC TIG or MIG can weld aluminum in breezy conditions.
Stick welding aluminum is possible and actually works better than I expected. I used 1/8" Harris 26 Aluminum Welding Electrodes that I purchased from Cyberweld.com. The electrodes use different flux than more common steel electrodes, but the process is basically the same. They recommend DCEP/DCRP, which makes sense. AC TIG is able to remove the oxide layer on the base metal during the electrode positive portion of the alternating current. DCEP constantly removes the oxide layer from the base metal while the electrode flux keeps oxides from forming on the electrode metal and the molten pool. The flux protects the weld as it cools and forms a protective barrier, which works great even in windy conditions. They key is to move faster than you would with a steel electrode and not much weave movement is required since the aluminum flows better than steel. I welded a 3"x6"x60" aluminum box section out of 3"x0.125" angle for a storm grate extension and used less than 1 pound of electrodes. That works out to 60" x 4 seams = 240", which would have used quite a few TIG filler rods and a significant amount of argon from my 40cuft bottle. The following video shows the basic process and my newbie welding skills. This bit of welding was done with my Everlast Super250P on a bottom side of the grate extension near the beginning of my learning curve. My welding and my welds got better as I progressed.
Here is the video:
www.youtube.com/watch?v=KELLTrgnUhc
Here are some photos of a nice section of weld that I laid down at 125A after shooting the video. The dotted line is from dragging the slag chipping hammer along the weld.
http://farm4.static.flickr.com/3370/...963e16.jpg?v=0
http://farm3.static.flickr.com/2483/...9e67b0.jpg?v=0
http://farm4.static.flickr.com/3583/...f6eaae.jpg?v=0
So, my conclusion is that stick welding aluminum is great when a lot of structural (read not-perfectly-cosmetic) welding is needed. It should be possible to lay some beautiful welds and weld thinner metal this way, but my skills are not there yet. I was able to weld at near MIG speed without a MIG welder at or under equivalent consumable cost. The 1 pound of electrodes was about $25 shipped. One pound of aluminum welding wire is currently about $20 and my argon bottle costs about $15 to fill up.
