I-CAR Welding Techniques and Processes 3

Question 1

What is the recommended minimum distance between a weld location and any OEM spot weld when adding supplemental MIG plug welds?

Accepted Answer

25 mm (1 inch)

Answer

I-CAR and most OEM procedures specify supplemental welds be placed at least 25 mm (1 inch) from existing spot welds to avoid distorting the heat-affected zones of adjacent welds.

Question 2

When sectioning a vehicle's B-pillar, why is staggering weld seams required if multiple layers are present?

Accepted Answer

To prevent all seams from aligning, which would create a single concentrated weak point

Answer

Staggering seams ensures no single cross-section contains more than one weld joint, distributing stress and maintaining structural integrity.

Question 3

What condition is indicated when a STRSW electrode tip mushrooms or deforms during use?

Accepted Answer

The electrode needs to be dressed or replaced to restore proper tip geometry

Answer

Mushrooming reduces contact pressure and increases contact area, resulting in undersized, weak weld nuggets; the tip must be dressed or replaced.

Question 4

What is the purpose of applying weld-through primer to bare metal flanges before assembling panels for welding?

Accepted Answer

It protects the hidden flange surfaces from corrosion after welding

Answer

Weld-through primer (zinc-based) protects the mating flanges that cannot be coated after assembly, preventing corrosion in areas inaccessible post-weld.

Question 5

Which of the following is the correct action if porosity is discovered in a structural weld on a completed repair?

Accepted Answer

Grind out the defective weld and re-weld with corrected technique and settings

Answer

Structural welds with porosity must be completely removed and re-welded after identifying and correcting the root cause, as porosity compromises load-bearing integrity.

I-CAR - Inter-Industry Conference on Auto Collision Repair Certified Practice Test

I-CAR - Inter-Industry Conference on Auto Collision Repair Certified Practice Test

I-CAR Welding Techniques and Processes 3