Originally Posted by David R
A true tack weld is made to break off if needed or hold things in position to be welded.
A series of tacks would be a series of welds made to break off.
I weld exhaust with an SP100 turned down C 3 .
I start at the top and make my way down. One pass each side.
Make a dry pass to see where the gun will fit if its on the car.
A 'tack' also needs to be strong enough to hold the parts in alignment and withstand the pressure of coaxing the rest of the weldment into alignment. And withstand the stresses of welding once the fit-up is complete.
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