Depends on the filler. If it is bronze, nickel, or something $$$ then I save it until it’s almost completely gone. If it is 5356, er70 or something cheap and common, I throw it in the bin. If you’re into art, there are often times plenty of projects that can use those small scraps too.

Nice work

On cast aluminum, I tend to use 4943 filler, and move slowly at first to get a feel for how the cleaning action is working. I usually start with around 75% balance and lower hertz (60-70) and tune from there…not all cast is created equal…I favor 2% lanth for these repairs.

Sometimes I will first run a lower amp dry pass over the repair area just to see what the cleaning action wants to bring up. You can use the grains of the casting to help line you up and index the part, then tacl, then carbide burr out the weld area to get better weld prep in there.

Peening can be helpful after some cast repairs. Especially on things that get post weld machining.

Too much heat, gas flow and specifically coverage after the weld arc is shut off and the bead is still cooling, will make it worse.

Try using less considerably less amps and as you start to get faster you can sturt bumping amperage up. More amps means you have to travel much faster.

These clamps come in kits, in many different thread sizes.

Those are machinist toe clamps, step clamps, hold down clamps…they have several names. One was just longer than the others to allow me to have a long sliding action with it.

I love my aluminum fixture plate for small parts like this, very very handy. The aluminum really helps keep arc strikes down. I need to make myself a larger aluminum one.

Aaron Laughlin typo, I meant ‘it’

That is such nice work.

In your tank, this is kinda one of those real world vs on paper situations. Real world, you are unlikely to have issues with stress corrosion cracking there imo. Many tanks that get anodized will be welded with 5356 to be a good color match post anodizing (there are other fillers you can use here too, but are not as common). In the marine world, this is more of an issue as it is in a very corrosive environment, as well as being susceptible to vibrations and movements that create more stress, add elevated temps in the mix and over time it is much more likely to crack. My experience has been that heat alone isn’t as big of a deal as heat, stress, AND corrosion.