Cert III Body Repair flashcards
Cert III Body Repair · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Panel gap tolerance
- The allowable variation in the space between two adjacent body panels, typically about 1-1.5 mm, measured at several points to confirm correct alignment after repair.
- High-strength steel heat limit
- A rule stating that high-strength steel heated above roughly 600 C loses tensile strength and must be replaced rather than straightened, unless the OEM procedure permits heat.
- Adhesive softening temperature
- The temperature, commonly about 90-120 C, at which structural adhesive softens enough for a bonded panel to be cut away during removal.
- Plug weld hole sizing
- A sizing rule where the hole diameter is about 1.2-1.5 times the thickness of the thinner sheet, allowing full fusion without excessive heat.
- Spot weld cutter size
- The diameter of the drill or cutter used to remove a spot weld, chosen to cut only the top sheet, typically around 8 mm for 0.8 mm steel.
- Backstep welding sequence
- A technique of making short welds in a staggered order so heat is spread across the joint, reducing distortion and panel warping during sheet metal repair.
- Paint film build limit
- The maximum total coating thickness, generally around 300 micrometres, above which solvent trapping, cracking, and poor adhesion become likely.
- Body filler layer thickness
- The recommended maximum thickness of a single body filler application, about 3-6 mm, applied only over clean bare metal or approved primer.
- Hammer and dolly on-stretch
- A panel-beating technique where the hammer strikes the panel while it is held against the dolly, stretching the metal to restore a crowned or stretched surface.
- Rivet removal without hole damage
- The process of drilling or milling a rivet head so the rivet can be punched out without enlarging or elongating the original hole in the panel.
- Rust perforation threshold
- A decision point where pitting deeper than about 1 mm or a hole through the metal requires the affected section to be cut out and replaced.
- Epoxy primer recoat window
- The period, often up to 24 hours or as stated on the product data sheet, during which a topcoat can be applied without sanding the epoxy primer.
- Classic panel gap target
- An even gap of about 4-6 mm between doors and guards on a restored classic, checked with a gap gauge before final paint.
- Soda blasting use
- A low-abrasion media blasting method suited to aluminium and thin steel panels, chosen to strip coatings without the heat and distortion caused by harsh grit.
- Body solder tinning
- The step of coating a cleaned steel surface with a thin solder layer so that lead-loading filler will bond, performed before the solder is built up.
- Primer surfacer grit
- The abrasive grade, commonly 400-600 grit, used to sand a high-build primer surfacer flat before sealer, base coat, and clear coat are applied.
- Metallic blend within panel
- A colour matching technique where metallic or pearl paint is faded into the panel rather than stopped at an edge, hiding a mismatch in flake orientation.
- Fastener grade matching
- The requirement that replacement fasteners match the original thread pitch, diameter, and strength grade so clamp load and joint integrity are preserved.
- Flash rust prevention
- The practice of applying epoxy primer to bare steel within the product recoat window to stop surface oxidation before topcoating begins.
- Trim replating specification
- Restoring original appearance by replating or replacing fasteners and trim to the manufacturer's finish and dimension, rather than substituting generic hardware.
- Frame diagonal measurement
- A check comparing opposite corner-to-corner distances on a chassis to detect squareness loss, referenced against the OEM frame dimension chart.
- Frame heat restriction
- A rule limiting heating of heat-treated truck frames to the OEM-specified temperature, commonly below 400-600 C, with quenching prohibited.
- Crack stop-drilling
- Drilling a small hole at each end of a frame crack to relieve stress concentration before the crack is grooved and welded.
- Fishplate reinforcement
- A steel plate welded or bolted over a repaired frame section to restore strength, used only where the OEM repair procedure permits it.
- Frame rivet grip length
- The combined thickness of the parts being joined, used to select a rivet of correct length so the formed head seats properly.
- Kingpin wear limit
- The minimum allowable kingpin diameter stated by the OEM, below which the kingpin must be replaced rather than adjusted or shimmed.
- Fifth wheel jaw wear
- The amount of material lost from the locking jaws of a fifth wheel coupling, checked against OEM limits because excess wear allows trailer separation.
- Torque in stages
- Tightening a fastener to its final OEM value in several increments, often in a pattern, so clamping load is even and the fastener is not overstressed.
- Body mount U-bolt check
- An inspection of body mounting U-bolts and isolators for elongation, corrosion, and correct torque, since loose mounts load the frame and cause cracking.
- Air line support interval
- The maximum spacing between clips supporting an air brake line, set by the OEM so the line cannot sag, rub, or contact heat sources.
- OEM frame pull limit
- The maximum force and direction a chassis may be pulled during straightening, stated by the manufacturer to avoid stretching or cracking the frame rails.
- Datum height check
- A measurement of specified points on the chassis relative to a reference plane, compared with OEM figures to confirm the frame is straight and square.