My TIG welding skills are nearly good enough to enter gas-tank-city! I've be going to the school of Youtube and practicing my welding most evenings. TIG welding steel is tough, but easy-peazy when compared to aluminum!
TIG welding aluminum is hard! And complex -- It's not just setting the current and welding (btw, I used 125 amps), but also ac frequency makes a difference (120 hz), and the AC balance control for cleaning (30%). Plus everything has to be clean -- as in wipe it down with acetone clean. You even need to use a
dedicated stainless steel wire brush to prep the surface for the weld. And a dedicated grinder wheel to shape the tungsten with.
While welding -- or attempting to weld anyway -- you have to hold the tungsten super close... but never touch the weld. When you touch the tungsten to the weld or to the rod you are dabbing into the puddle. You are done. Stop and regrind your tungsten before continuing.
(I spend a lot of time grinding 
)
But wait! There's more! You gotta hold the torch at the correct angles! Yea, angle
S -- plural -- You not only have to aim the arc into the joint center -- or, for non matched materials, offset the arc slightly to the thicker material side -- all while still angling the torch back from the travel directly by 15-ish degrees.
Oh no, you're not done yet though -- Now you had to dab the rod into the molten puddle frequently (1x/second-ish or faster... but at a consistent pace to match the puddle travel)...but you can't leave the rod too close to the arc when not dabbing or the end will soften and droop.
Remeber the current setting? It's just a suggestion... the upper limit of the current that the welding will send to the torch. You actually control the current flow with the foot pedal to maintain that perfect molten puddle... but then, aluminum doesn't color change as it heats and melts. It gets frosty from the cleaning when you start, then turns shiny, then reflective once the aluminum is molten.
That's your cue that it's time to dab and move!
Finally, you are welding and you need to move along the joint and weld the parts together - you can either incrementally about 1/8" at a time -- move, melt, dab, move, melt, dab, etc...., Or, you can move smoothly across the metal pushing the reflective spot along the joint all while dabbing over and over. Both methods sound easy, right? WRONG! If you choose incremental movements, you need to watch that puddle expand, dab, and them move exactly the same distance you did on the last move (or it will look bad!), then wait for the puddle to grow to the exact size of the previous puddle, then dab and move again, and again, and again!) Of course, I tend to do better with the small incremental movements that I do with the continuous moving. To do the smooth, continuous move, you need to move along the joint smoothly. Your speed and/or the pedal are how you control the puddle size... Move too quickly and you leave bird droppings along the joint. Too slow and the material sags, then blows through.
Sounds awful, right? But, I love it! It's actually kind of a thrill... everyone should try tigging at some point! Seriously, find a neighbor with a TIG welder, take a class at the local community college. Totally worth it!
While not even close to a stack of dimes or internet presentable, this cube -- well, open-top-cube, has some passable welds! (the cube below is from a few days ago -- not nearly as good as tonight's cube!
And BTW, welding is hot... Do you have any idea of what the BEST way to discover that your TIG gloves have strategically placed holes is? I know! OUCH!
So, a new pair of gloves and a few more cubes and I'll be ready to fork out the cash to buy a 4'x8'x1/8" sheet of aluminum that I, with my mediocre TIG skills, will turn into a Patrol gas tank that will fit right into the stock space with the stock tank shield too!
Happy Sunday!
j
