It's tacked together as hot as my little 110 mig will go.
I find it best to preheat any thick welds with a propane torch to give them a chance of some penetration.
Now that the geometry is locked in I can take it to my buddies shop and have him run some beads on it.
Will a strut bar actually do very much?
Will I ever be a good enough driver to be able to tell the difference?
Do I care if the answer to these questions is no?
No.