Welding & Metalworking Techniques Flashcards
7 cards from real CCC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Welding & Metalworking Techniques flashcards as text
In collision repair, what is the recommended technique for welding a butt joint on thin body panels?
Answer: Tack welds spaced evenly, then fill between with stitch welds, allowing cooling between passes
Tacking at intervals followed by stitch welding with cooling pauses distributes heat evenly across the panel, minimizing distortion and warpage on thin sheet metal.
What does porosity in a weld indicate in collision repair?
Answer: Gas pockets trapped in the weld caused by contamination, moisture, or shielding gas issues
Porosity appears as small holes or voids within the weld caused by trapped gas from contamination, insufficient shielding gas coverage, or moisture on the base metal or filler wire.
Which metal cutting tool is preferred for making precision cuts in automotive sheet metal to minimize heat distortion?
Answer: Reciprocating saw or metal-cutting shears
Reciprocating saws or metal-cutting shears produce clean cuts with minimal heat input, preserving panel shape and reducing warpage compared to thermal cutting methods.
When should a technician use a plasma cutter versus metal shears when sectioning panels in collision repair?
Answer: Shears are preferred for straight cuts on thin panels; plasma cutters excel at curves or thick metal
Metal shears make clean, low-heat straight cuts on thin panels while plasma cutters are more efficient for curved cuts, intricate shapes, or thicker metal sections.
What is the correct procedure after completing a weld on a galvanized panel to restore corrosion protection?
Answer: Clean the weld, apply weld-through primer or zinc-rich coating to the affected area
After welding galvanized panels, the heat-affected and bare metal zones must be treated with zinc-rich primer or coating to restore the corrosion protection removed by the welding process.
What condition is described when a weld bead does not fully fuse with the base metal on one or both sides?
Answer: Lack of fusion (incomplete fusion)
Lack of fusion occurs when the weld metal fails to bond completely with the base metal or adjacent weld passes, creating a weak joint prone to cracking under stress.
What is the maximum gap allowed between panels before a backing strip or insert should be used when butt welding automotive body panels?
Answer: Up to 1/16 inch (1.6 mm)
Industry best practice allows a maximum gap of approximately 1/16 inch (1.6 mm) for butt welds; larger gaps require a backing strip to support the weld pool and ensure full penetration without burn-through.