I-CAR Welding Techniques and Processes 2

Question 1

What is the correct sequence for performing a MIG plug weld on a structural panel?

Accepted Answer

Weld around the perimeter of the hole, then fill the center

Answer

Fill the center of the hole first with a single pass

Answer

Tack the edges, grind, then fill

Answer

Start at the center and weld in a circular outward motion

Question 2

When using STRSW equipment, what parameter most directly determines weld nugget size?

Accepted Answer

Electrode tip diameter

Answer

Weld current (amperage)

Answer

Electrode force (squeeze pressure)

Answer

Weld time (cycles)

Question 3

What is a 'destructive weld test' used to verify in collision repair?

Accepted Answer

That the weld settings produce a weld nugget of adequate size and penetration on scrap metal

Answer

That the welding machine is calibrated correctly

Answer

That the repaired panel has correct dimensions

Answer

That shielding gas flow rate is set properly

Question 4

Which type of weld joint is most commonly used when installing a sectioned structural rail?

Accepted Answer

Butt weld joint with backing

Answer

Lap weld joint

Answer

T-weld joint

Answer

Edge weld joint

Question 5

Why must aluminum welding use a dedicated MIG welder or torch liner, separate from steel equipment?

Accepted Answer

Steel contamination from shared liners causes porosity and weld defects in aluminum

Answer

Aluminum requires a different shielding gas regulator

Answer

Aluminum cannot be welded with MIG at all

Answer

The wire feed speed is different for aluminum

Question 6

What does 'wire feed speed' control in a MIG welding setup?

Accepted Answer

The rate at which filler wire is delivered to the weld pool, which determines amperage

Answer

The voltage of the arc

Answer

The travel speed of the welder

Answer

The flow rate of shielding gas

Question 7

Which weld defect appears as small holes or voids within the weld bead and is often caused by contamination or inadequate shielding gas?

Accepted Answer

Porosity

Answer

Undercut

Answer

Cold lap

Answer

Overlap