So bout a month and a half ago I had tnt unibody stiffeners and aj's sliders welded on. Now, where the welds are is rust, along with the 3rd leg we added. I primered and painted both before install. Is this normal?

 

probably just surface rust since you just welded those on. Grind the rust off and if you worried about buy some POR-15 and be done with it.

 

Did you paint and prime over the welds too?

If not that's why..

 

no I didn't dam ill have to do it this weekend. Do I need a grinder or will sandpaper work?

 

go pick up a 4in grinder and a flap wheel.

 

whats a flapwheel? Looking online 4in grinders $27 so Ill pick one up. Is using it pretty easy and straight forward?

 

flap wheels are bad (in a good way)

google them. there are the best way to sand metal

 

Is it gonna weaken anything if I grind it down? How far should I grind it? Looks to be mainly surface rust.

 

grind until the rust is gone

 

just hit it long enough to clean them up were there is no more rust on them