Cert III Body Repair key terms

A vehicle construction where the body panels and floor form the main load-bearing structure, so there is no separate full frame underneath carrying the weight.

A construction in which a separate steel chassis carries the load and the body shell is bolted on top, common on utilities and heavy vehicles.

A section of the front or rear structure designed to fold and absorb crash energy, keeping the passenger cell intact during an impact.

The engineered way a vehicle redirects and absorbs impact forces through designed deformation paths rather than passing them to occupants.

Cutting out a damaged portion of a welded body structure and welding in a matching replacement piece at manufacturer-approved cut points.

Replacing part of a structural panel rather than the whole panel, using approved join locations and correct weld type and spacing.

A small circular weld made where two overlapping metal sheets are pressed together and current is passed through them to fuse them.

A weld made by filling a hole drilled or punched in the outer panel so the weld fuses the outer sheet to the one beneath it.

A series of short welds with gaps between them, used where continuous welding would add too much heat or distortion.

A hole saw or drill bit with a pilot pin used to cut through the top sheet of a spot weld so panels can be separated without tearing the metal.

Warping or buckling of sheet metal caused by uneven heating and cooling during welding, controlled by stitch welding and heat management.

A panel-straightening technique where a heated area is rapidly cooled to contract stretched metal and remove an oil-can or bulged area.

Reshaping damaged sheet metal back to its original contour using hammers, dollies and spoons rather than filling over the damage.

A shaped block of steel held behind a panel to back up hammer blows so the metal is stretched and shaped against a solid surface.

A long-handled steel or alloy tool used to press or tap out low spots and crowns while the panel is supported from behind.

A two-part polyester paste applied to a prepared panel to level minor imperfections before primer and paint are applied.

A thin contrasting mist of paint or powder sprayed over primer or filler so low spots and sanding scratches become visible during block sanding.

Sanding with a rigid or semi-rigid block behind the abrasive so the surface is flattened rather than following the contours of the damage.

The uniform clearance between adjacent body panels such as doors and guards, checked for evenness after repair or replacement.

Adjusting hinges, latches and mounting points so panels sit flush with even gaps and close correctly without binding.

Placing thin metal or plastic spacers behind a hinge or mounting point to move a panel outward and even up its gaps.

A main longitudinal structural member of a frame that runs front to rear and carries the vehicle's load and suspension forces.

Pulling a bent chassis or body structure back to its specified dimensions using hydraulic rams and measured reference points.

A reference location on a vehicle's structure, listed in manufacturer data, used to measure and confirm correct alignment after damage.

A set of gauges, tram bars or electronic targets used to compare a vehicle's actual dimensions against the manufacturer's specification.

A rubber or urethane cushion and bolt assembly that attaches a body shell to the chassis and isolates vibration.

A joining method combining structural adhesive with rivets, used on aluminium and mixed-material bodies where welding is unsuitable.

A high-strength two-part adhesive used to bond panels and provide load-bearing joints, often in combination with rivets or welds.

Accelerated corrosion that occurs where two different metals such as steel and aluminium are joined and moisture bridges them.

Separating unlike metals with coatings, sealers or isolating washers so they cannot form a corrosive electrical couple.

A waxy coating sprayed inside enclosed box sections and pillars after repair to protect bare steel from internal rust.

A protective layer such as zinc-rich primer, seam sealer or wax applied to repaired areas to restore the factory's rust protection.

A flexible paste applied over welded and lapped joints to keep water out and restore the factory appearance of the join.

The process of removing a welded or bonded panel by cutting welds, drilling rivets or releasing adhesive without damaging the structure beneath.

A hand-held meter that measures coating depth on steel or aluminium so prior repairs and filler can be detected before sanding.

The reinforced point where a strut, spring or control arm attaches to the body or chassis, critical to wheel alignment and safety.

Adjustment of camber, caster and toe so wheels sit at the angles specified, checked after any structural or suspension repair.

Reading a vehicle's electronic systems for fault codes before and after body work to confirm driver-assist and safety systems still function.