The rear window/frame on my pickup trucks shell is about 15 or so years old and is getting tired. The aluminum hinge/frame was starting a crack along the hinge assembly, and is composed of a chunk of L aluminum, about 1/16" thick.
Not having any aluminum of the proper type on hand, Ive been pondering this for a couple weeks, and have been waiting for the entire window/hatch to fall off on the freeway....cringe.
So today..in an insane moment of bravado and balls..I decided to TIG weld up the 12" long crack, and also reinforce other weak areas.
So I drug the ground, tig torch, foot pedal and stainless steel brush over to the now backed intotheweldingarea pickem up truck..and thought about how to proceed. The crack was only acessable with the hatch open, and then from underneith. This meant I had to overhead weld the dreaded aluminum thin stuff...GACK!!!!! OMGODthisisgonna be a bitch..and it was.
I fired up the Airco Squarewave 300, rounded a 3/32 2% lanthanated electrode (per Ernie) on a chunk of stainless steel, Electrode positive, then switched to AC, scrubbed the snot out of the aluminum with a SS wire brush..then pondered the first problem...foot pedal.
The only way I could reach the crack, was sitting tailor fashion on the tailgate, facing the front of the truck and working overhead. No way to push the pedal..so I put it under my left thigh, and could push by moving my leg a bit. This of course lead to serious leg cramps..zapping myself with the HV at least once..sigh.
The frame was insulated from truck ground by the fiberglass of the shell, so I didnt have to worry about zapping the computer etc..which was a small blessing.
I started the arc..and started heating the aluminum..and found the current wasnt high enough, so I set it up for max 125 amps, with start current of 30%..made the best guess at the balance, backround and pulse, then assumed the position again..and again got a cramp..resulting in a flinch..sticking the electrode to the frame...sigh.. resharpening..I tried it again..
Pressing down with my leg..I could see the aluminum start to melt..and I fed in a little aluminum filler..which balled up, and fell onto my crotch. I could smell jeans burning...as I instantly fell off the tailgate in a desperate struggle to protect the family jewels. Now Im upside down, wrapped in ground cable, tig hose, the foot pedal teeters on the tailgate..then falls on my crotch. What the hot dingleberry didnt scorch..the pedal crushed.
Getting out my leather apron (hindsight is 2020)..I reassumed the position again..but a bit more gingerly...I fired up the arc again..this time waiting for the base metal to start to go all silvery, then gently dabbed the filler into the silver puddle...
SOB...it melted into the puddle..and stayed there...Fuck me running..its working!!! Im welding Im welding! Buawahahahhaha!
Paying close attention..I managed to run at least 10" of the 12" with a clean, neat bead. Not stack of dimes..but still nice (for me). Then I got a leg cramp, stuck the electrode into the puddle..filled the entire cup of the torch with melted aluminum and fell off the tailgate again as the cup exploded, raining hot shit all over me..including under my mask, down my neck. But my crotch was protected!!!!
Brush off the singed chest hair, installed a new cup, regrind of the electrode, reposition, scrub vigorously with the brush again, fire up the arc, and finish the weld in a pretty matter of fact fashion..forgetting of course to creep up on the end of the material..and melting the last 1/4" completly, down into the cup of my torch again..which fortunately didnt explode this time.
Well Ill be damned..I actually overhead welded aluminum. Mostly. Had some icicles hanging, there at the end of the weld..which I took care of with a 4 flute 1/4" endmill in an air die grinder..worked really slick.
If Id been smart..and had a helper, I should have taken the 30 minutes to pull the shell off the truck, and turned it over..but hey..Ive been called a lot of things..but never smart..and there wasnt a helper handy.
Now I can reeeeely understand the utility value of one of those torch mounted controls and why spool guns are so popular. I have a mig..but not the proper liner etc etc though I do have several spools of aluminum mig wire (which I was using for filler.)
But Im totally tickled..Ive gone from Daubers Helper, to Daubers Apprentice 1.
Maybe an old dog can learn new tricks.
This just opened up a whole new can of worms for me..now that I can melt aluminum together. Sorta. Kinda. A little. Somewhat......
"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