NITA Panel Beating & Spray Painting Trade Test cheat sheet

Isocyanate hardeners (2K polyurethane paints, clearcoats, primers) cause occupational asthma; supplied-air respirators are required for spray application, and cartridge masks are not adequate protection.

Flash point below 23 °C classifies a liquid as highly flammable (Category 1); standard booth solvents and thinners typically fall in this class, so ignition sources, smoking and non-EX-rated equipment are excluded from the spray area.

LEL/UEL define the explosive range of a solvent vapour in air; gas detection and booth airflow must keep concentrations well below 10 % LEL during spraying.

Booth airflow is measured as face velocity across the open booth face; typical target is 0.4–0.5 m/s for a cross-draft booth, with make-up air filtered and extracted through the exhaust stack.

Dust from sanding primers and fillers is a respiratory and explosion hazard; wet sanding, dust extraction at the tool, and ATEX-rated vacuum systems reduce airborne concentration.

Solvent containers must be bonded and earthed during decanting to prevent static ignition; earthing continuity is checked before transfer of thinners or basecoat.

Waste streams are segregated: waste solvent and paint sludge are hazardous waste, cured paint solids and metal swarf are separate streams, and spray booth filters are disposed of as hazardous waste.

Noise above 85 dB(A) (8-hour exposure) requires hearing protection and audiometric surveillance; air tools and hammer work commonly exceed this level.

Personal protective equipment hierarchy: eliminate/substitute the product first, then engineering controls (booth, extraction), then administrative controls, with PPE as the last line of defence.

Panel hammers are classified by face shape: flat, pick/pointed, cross-chisel, shrinking, and slapper; the face profile determines whether the tool stretches, planishes or shrinks the metal.

Dollies are matched to hammer faces: a flat dolly under a flat hammer planishes, while a curved or heel dolly supports a curved panel during off-dolly work.

Body files are used for level detection and metal removal; a flexible file follows panel curvature, a rigid file reveals high and low spots on flat surfaces.

A slide hammer (dent puller) applies a pulling force through a welded stud or a self-tapping screw; the pulling direction must be opposite the deformation direction.

Air sanders are rated by orbit diameter and orbit type: a 5 mm orbit with a soft pad is typical for primer, a 2.5 mm orbit for finishing, and a random orbital action reduces pigtail scratches.

Spray gun nozzle (fluid tip) size is matched to material: 1.2–1.3 mm for basecoat and clearcoat, 1.4–1.6 mm for primer and high-build surfacer.

Torque wrenches, ball-joint separators and pullers are used for suspension and structural fasteners; torque values are taken from the manufacturer's data, never estimated.

Compressed-air quality is part of tool performance: a refrigerated dryer plus coalescing filter supplies dry, oil-free air; moisture causes paint defects and shortens air-tool life.

A body-over-frame (ladder frame) design carries load in a separate chassis; a unitised (monocoque) body uses the welded body shell as the load-bearing structure, so any structural repair affects crash performance.

Crash energy management relies on controlled deformation: front and rear crumple zones absorb energy while the passenger safety cage (A/B/C pillars, sills, roof rails, floor cross-members) resists deformation.

High-strength steel (HSS) and ultra-high-strength steel (UHSS/boron steel) are common in pillars, sills and bumpers; they must not be heated above their tempering range, and repair methods are restricted by the manufacturer.

Aluminium body structures require isolation from steel to prevent galvanic corrosion; dedicated tools, rivets and adhesives are used, and mixed-material joints need the specified fasteners.

Closure panels (doors, bonnet, boot lid) are typically bolted or hinged to the body; fenders and front panels are often bolted to allow adjustment and replacement.

Seam sealers, cavity wax and anti-flutter foam are part of the body structure's corrosion and NVH control; they must be reinstated after structural repair.

Sectioning is permitted only at manufacturer-approved cut points; a sectioning joint must not fall in a crush zone or within a specified distance of a reinforcement.

Bolt-on versus weld-on panels: bolt-on panels are replaced as assemblies, while weld-on quarter panels and roof panels require cutting, alignment and welding.

Steel sheet thickness and grade determine repair method; a panel marked HSS or UHSS is not straightened with heat unless the manufacturer permits it.

Galvanised and zinc-coated steels require removal of coating at weld and adhesive zones; zinc vapour from welding is a fume hazard requiring extraction.

SPR (self-piercing rivets), blind rivets, flow-drill screws and structural adhesives are the standard joining methods for aluminium and mixed-material bodies.

Bonded joints rely on surface preparation (abrasion, cleaning, primer) and controlled adhesive bead dimensions; the adhesive's open time and clamp time are specified by the product data sheet.

Threaded fasteners are classified by grade (e.g. 8.8, 10.9) and property class; a replacement fastener must match or exceed the original grade and the specified torque and angle.

Torque-to-yield (TTY) bolts stretch on tightening and must be replaced after loosening; they are not reused.

Plastic and composite panels (bumpers, grilles) are repaired with plastic welding or two-part adhesives; the plastic identification code on the reverse side determines the repair method.

Corrosion protection is restored at every repair: zinc-rich primer on bare steel, seam sealer at joints, cavity wax inside box sections, and anti-chip coating on lower body areas.

Damage assessment proceeds from the impact point outward: direct damage, then induced damage (creased panels, misaligned gaps), then indirect damage (suspension, steering, cooling, electrical).

Gap and flush measurement at adjacent panels (doors, bonnet, boot) reveals body distortion; a change in gap width along a seam indicates a pushed or pulled structure.

A damage report records the impact direction, height and severity; paint transfer and crush depth help reconstruct the collision energy.

Hidden damage is checked by inspection of inner panels, rails, apron and floor; a visual check of the outer skin alone is not a complete assessment.

Structural damage requires measuring-system verification before and after pulling; cosmetic repair proceeds only after the structure is confirmed within tolerance.

Supplementary restraint systems (airbags, pretensioners) and sensors are inspected after impact; deployment or crash-signal storage affects the repair scope and cost.

Repair-versus-replace decisions weigh panel accessibility, material grade, repair cost, corrosion risk and manufacturer restrictions; a UHSS part is often replaced, not straightened.

The assessment feeds the estimate: parts, labour operations, paint materials, sublet work and consumables are itemised so the job card and customer authorisation match.

Body dimensions are checked against the manufacturer's datum points using a measuring system: a dedicated fixture, a universal measuring system, or a laser/electronic system referenced to control points.

Datum points are specified in three axes (length, width, height); a measurement outside tolerance indicates structural movement that must be corrected before panel fitting.

Panel gap and flush targets are manufacturer-specific; typical door gaps are set to a uniform value along the seam, checked with a gap gauge and a flush gauge.

Alignment sequence: establish the fixed reference (usually the rear body or a known good side), then fit and adjust closures from the reference outward.

Hinge adjustment uses shimming and slot movement; door alignment is set at the hinge first, then at the striker, and finally at the latch.

Pulling a structure requires anchoring the vehicle and applying a controlled pull in the opposite direction of the impact; the measurement is re-checked during pulling to avoid over-pull.

A twisted body shows diagonal measurement differences; cross-measurement between opposite datum points reveals diamond or sway damage.

After structural correction, all closures are trial-fitted before paint; gaps and flush are confirmed with the vehicle on a level surface and at kerb weight.

Steel stretches when beaten on-dolly (hammer and dolly in contact through the panel) and shrinks when worked off-dolly with a pick hammer against a dolly held behind the low area.

Shrinking methods: heat shrinking with a torch and a wet rag or air blast, and mechanical shrinking with a shrinking hammer or shrinking dolly; heat is applied in small spots to avoid warping.

A high spot is lowered by off-dolly picking around it or by shrinking the surrounding stretched metal; a low spot is raised by on-dolly planishing or by pulling.

Planishing is a low-force, overlapping hammer sequence that levels the surface and relieves internal stress; it follows rough shaping, not precedes it.

Metal finishing uses a body file and a hammer/dolly to bring the panel within a few thousandths of an inch; filler is then applied thin, not used to fill deep depressions.

Stretching is used to gain surface area, for example to remove a crease or to shape a crown; excessive stretching thins the metal and reduces its strength.

Heat on HSS/UHSS is restricted: heating above the tempering temperature alters the microstructure and reduces crash performance, so the manufacturer's repair limits govern.

Aluminium requires dedicated hammers and dollies to avoid cross-contamination; it work-hardens quickly and needs annealing according to the alloy's specification.

MIG/MAG welding is the standard for steel body panels; the shielding gas (typically Ar/CO2 mix) and wire diameter are matched to sheet thickness.

Squeeze-type resistance spot welding (STRSW) reproduces factory welds; the welder's electrode force, current and cycle time are set for the sheet stack, and a test weld is destructively checked.

Plug (rosette) welding through a punched hole is used where a spot welder cannot reach; hole diameter and weld count follow the manufacturer's specification.

MIG brazing (bronze wire) joins coated and high-strength steels at lower heat input, reducing zinc burn-off and heat distortion; it is not a fusion weld.

Structural adhesives are used with or without rivets; the bond gap is controlled by glass beads or the adhesive's own bead, and clamp time must be respected before handling.

Weld-through primer is applied at mating flanges before welding to protect the joint; it must be a weldable grade and applied thin.

Aluminium welding requires AC TIG or specialised MIG with push-pull torch, dedicated wire and a clean, oxide-free surface; steel tooling must not contact the aluminium weld zone.

Brazing filler melts above 450 °C but below the base metal's melting point; the joint is capillary, not fused, and flux residue must be removed to prevent corrosion.

Polyester body filler is mixed with a hardener (MEKP) at the manufacturer's ratio, typically 1–3 % by weight; too much hardener causes shrinkage, porosity and poor adhesion.

The substrate must be clean, dry, abraded and free of wax, silicone and oil; bare steel is primed before filler, and galvanised steel is abraded and primed with an appropriate primer.

Filler is applied in thin layers, with each layer cured before the next; thick single applications trap solvent and shrink, causing sanding scratches and sink marks.

Feather-edging the filler edge into the surrounding paint prevents a visible ridge; the transition is sanded with progressively finer grits.

Filler should not be used to bridge rust holes, deep creases or structural damage; those areas are repaired with metal or replaced.

Sandpaper grit sequence for filler: coarse (e.g. 40–80) for shaping, then 120–180 for levelling, then finer grades on primer before topcoat.

A guide coat (a light mist of contrasting colour) reveals low spots and sanding scratches during blocking; it is sanded away to show the level surface.

Filler over cured primer requires the primer to be sanded and cleaned; filler over a wet or uncured surface traps solvent and causes blistering.

Surface preparation sequence: wash with a wax and grease remover, abrade, clean again, then apply the specified primer; skipping the wash drives contamination into the substrate.

Sanding scratches must be finer than the topcoat's hiding power; a 320–400 grit finish on primer is typical before basecoat, and finer grades are used on blend panels.

Wet sanding controls dust and heat but requires thorough drying before painting; trapped water causes blistering and poor adhesion.

Machine sanding with a random orbital sander reduces pigtails; a fixed-orbit sander can leave swirl marks that show through metallic basecoats.

Bare metal is primed immediately after abrading to prevent flash rust; epoxy primer provides corrosion protection and adhesion.

Masking uses the correct tape and paper for the job: fine-line tape for edges, paper or plastic sheeting for large areas, and plugs for apertures; masking must not trap solvent.

Tack rags remove dust before paint; they are used lightly and not rubbed, because tack rags can leave residue on the surface.

Blend panels are prepared by abrading and cleaning beyond the repair area, then applying a blender or blending solvent to melt the edge of the new paint into the old.

Two-pack (2K) products are mixed with a hardener and have a pot life; the mixed material must be used within the pot life, and the mixing ratio is by volume or weight per the product data sheet.

Reducer (thinner) selection depends on temperature: slow reducer for hot conditions, fast reducer for cold, to control flow and solvent pop.

Spray gun setup: fluid tip size, air cap, inlet pressure and fluid flow are set to the product's specification; a test spray pattern on masking paper confirms atomisation.

Spray technique: 50 % overlap, gun distance 15–20 cm, gun speed constant, and the wrist kept perpendicular to the surface to avoid a dry or heavy edge.

Flash-off time between coats allows solvent to escape; too short a flash-off causes solvent pop, too long causes poor intercoat adhesion.

Film build is measured in microns; basecoat, clearcoat and primer each have a specified dry film thickness range, and a gauge checks the result.

Booth temperature and humidity affect cure and flow; high humidity causes blushing on some clearcoats, and low temperature slows curing.

Gun cleaning after each use prevents dried material from blocking the nozzle and causing a spitting or uneven pattern.

Runs and sags result from too heavy a coat, too slow a reducer, too close a gun distance or too slow a gun speed; correction is sanding and recoating.

Orange peel is a rough, textured finish caused by poor atomisation, too high a viscosity, too fast a reducer or incorrect gun distance; it is corrected by sanding and polishing or recoating.

Solvent pop appears as small blisters or pinholes caused by trapped solvent; it follows too short a flash-off or too heavy a coat.

Fish eyes are circular craters caused by silicone or oil contamination on the surface or in the air line; the surface must be cleaned and the air supply filtered.

Blushing is a milky haze in the clearcoat caused by moisture in the air line or high humidity; it is prevented by drying the air and controlling booth humidity.

Dry spray is a sandy, non-glossy texture caused by too fast a reducer, too much gun distance or too high an air pressure; the surface is sanded and recoated.

Sink marks appear over filler or repaired areas after curing because the repair shrinks; they are prevented by thin filler layers and proper curing.

Colour mismatch or mottling in metallic basecoat is caused by uneven application or incorrect gun distance; a uniform, overlapping pass and a blender control the metallic orientation.

Colour matching starts with the vehicle's paint code, but the code alone is not enough; variant chips or a spectrophotometer reading match the actual faded finish.

Metallic and pearlescent colours change with viewing angle; a test card is sprayed and compared at different angles before the panel is painted.

Blending extends the new colour into adjacent panels so the eye cannot detect a colour or texture difference; the blend area is prepared and a blender is used at the edge.

Polishing removes sanding scratches and orange peel; the sequence is compounding, then polishing, then a protective wax or sealant.

Clearcoat thickness and cure time affect gloss; polishing too soon after painting can dull the finish or trap solvent.

Paint edges at panel gaps and apertures are finished with a fine brush or a spray-out card to avoid a hard edge.

Colour match under booth lighting and daylight can differ; the final check is done in natural light before delivery.

Paint warranty and customer expectations: the match is judged against the adjacent original panel, not against a colour chip.

Trim clips and fasteners are single-use in many cases; a removed clip that has lost its retention is replaced, not reused.

Window glass removal and refitting requires the correct urethane adhesive, primer and setting time; the safe-drive-away time is specified by the adhesive manufacturer.

Windscreen replacement affects structural integrity and airbag performance; the glass is part of the safety system, and the bonding surface must be prepared per specification.

Electrical connectors are released with their locking tabs, not pulled by the wire; a broken connector or damaged pin causes intermittent faults.

Final assembly sequence: fit closures and adjust gaps, fit trim and glass, connect electrical and check function, then clean and inspect before delivery.

Water leak testing is done with a controlled water spray after glass and trim fitting; leaks are traced to the seal, not assumed to be the glass.

Calibration of driver-assistance sensors (camera, radar) is required after windscreen replacement or suspension/alignment work on equipped vehicles.

A pre-delivery inspection checklist records gaps, function tests, paint finish and cleanliness, and the customer signs acceptance.

An estimate itemises parts, labour (with operation times from a labour guide), paint and materials, and sublet work; it is the basis for the customer authorisation and the job card.

A job card records the vehicle details, customer complaint, authorised work, parts used, technician time and completion sign-off; it is the workshop's legal and commercial record.

Supplementary authorisation is required when hidden damage is found after the estimate; the customer is contacted before additional work proceeds.

Labour time is charged in the manufacturer's or industry labour guide units; overlapping operations are not double-charged.

Paint and materials are charged by a materials schedule or a percentage of the paint labour, depending on the agreed method.

Customer care includes explaining the repair scope, expected completion time, warranty terms and the reason for any delay; a written record of the conversation is kept.

Records must be retained per the jurisdiction's requirements and include the estimate, authorisation, job card, parts invoices and paint mixing records.

A quality control check before delivery compares the repair against the estimate and the vehicle's original condition; the customer signs off on collection.

Boron steel (hot-stamped, ~1500 MPa) is used in B-pillars and roof rails; it is not repairable by heating or straightening and is replaced as a section or assembly.

Rivet bonding combines structural adhesive with rivets; the adhesive carries load and the rivets hold the joint during cure, so both are required.

Magnesium and carbon-fibre components require dedicated repair methods and isolation from steel fasteners to prevent galvanic corrosion.

Fastener reuse rules: torque-to-yield bolts, self-locking nuts and many aluminium fasteners are single-use; the manufacturer's specification governs.

Thread repair uses a helicoil or a specified insert; the repair must restore the original thread class and torque capacity.

Seam sealant compatibility: some sealers are not paintable or not compatible with the primer system; the product data sheet confirms compatibility.

Weld quality is verified by destructive test coupons and visual inspection; a cold weld or a weld with insufficient penetration is rejected.

Mixed-material joints require isolation washers or coated fasteners to prevent galvanic corrosion between dissimilar metals.

Safety data sheets (SDS) for every product in the shop must be accessible; the SDS gives the hazard classification, PPE, first aid and disposal requirements.

Spray booth filters are changed on a pressure-drop schedule; a loaded filter reduces airflow and increases solvent concentration in the booth.

Respiratory protection is fit-tested; a beard or an ill-fitting mask breaks the seal and provides no protection against isocyanates.

Solvent exposure is monitored by workplace air sampling; the exposure standard is an 8-hour time-weighted average with a short-term limit for some solvents.

Fire safety: solvent storage cabinets, earthing of containers, and extinguishers rated for flammable liquids are required; water is not used on solvent fires.

Environmental controls include bunded storage, spill kits, and licensed disposal of paint sludge, waste solvent and contaminated filters.

Hand-arm vibration from air tools and hammer work is managed by tool selection, low-vibration tools and exposure time limits.

Emergency procedures: eyewash stations and safety showers are located near mixing areas, and spill and fire drills are recorded.

A body file is used with a light, even stroke; heavy pressure bows the file and produces a false reading of the panel's level.

Stud welders for dent pulling use a capacitor discharge; the stud, the grounding clamp and the panel surface must be clean for a sound weld.

A panel stand or rotisserie allows access to both sides of a panel; it is used for structural and restoration work where access is limited.

Air tool maintenance: oil daily, check the regulator and filter, and inspect hoses for cracks; a failed hose whips and causes injury.

Measuring systems (fixtures, universal, electronic) are calibrated; a measurement taken with an uncalibrated system is not evidence of a correct repair.

A hydraulic body jack or ram applies controlled force for pushing out dents; the reaction point must be spread over a large area to avoid new damage.

Cutting tools: a reciprocating saw or a cut-off wheel is used for sectioning; the cut line is marked at the approved sectioning point, and the cut is deburred.

A welding machine's duty cycle limits continuous use; exceeding it causes overheating and a poor weld.

Damage classification: cosmetic (paint and trim), panel (bolt-on replacement), structural (rails, aprons, pillars) and mechanical (suspension, steering, driveline).

A structural inspection includes the floor pan, inner sills, rails and strut towers; a crease in a rail indicates energy absorbed by the structure.

Symmetry check: comparing left and right sides at the same datum points reveals a sway or diamond condition.

Airbag and pretensioner inspection after deployment includes the clock spring, wiring and the crash sensor; a deployed system is replaced, not reset.

Repair cost versus vehicle value: a repair approaching or exceeding the vehicle's value is a total loss, and the customer is informed.

A damage report with photographs and measurements supports the estimate and any insurance claim.

Hidden damage is often found only after the outer panel is removed; the estimate must allow for supplementary authorisation.

Pre-repair scan of the vehicle's electronic systems records fault codes caused by the impact and protects both the shop and the customer.

The vehicle is anchored at the manufacturer's specified points; anchoring at the wrong points distorts the structure during pulling.

Pulling is done in stages with measurement between pulls; a single heavy pull over-stretches the metal and creates new damage.

Heat is used during pulling only where the manufacturer permits it; heat on HSS/UHSS is restricted.

Panel gap tolerance is typically ±1 mm on a modern vehicle; the gap is measured at several points along the seam, not at one.

Door alignment sequence: hinge adjustment for the front gap and flush, striker for the rear gap, latch for the closing effort.

A misaligned bonnet can indicate a bent hinge, a distorted apron or a structural shift; the cause is diagnosed before adjustment.

After structural repair, a four-wheel alignment checks the suspension and steering geometry, which can be affected by body movement.

Electronic measuring systems compare the vehicle to the manufacturer's data; the report is filed with the job card.

A slapper is used with a dolly to planish large, gently curved panels; it spreads the force over a wide area and reduces hammer marks.

A pick hammer concentrates force on a small area and is used for raising low spots and for shrinking with a dolly behind.

Heat shrinking is done in small spots, quenched with a wet rag or air; overheating a large area causes warping and loss of strength.

A shrinking disc generates friction heat over a controlled area and shrinks without a flame; it is used on panels where a torch is not suitable.

Metal finishing is judged by the file and by hand feel; a panel that is within a few thousandths of an inch needs only a thin filler or primer.

A crease is removed by working from the ends toward the centre and from the outside toward the crease; working the crease directly stretches it.

Aluminium is annealed by heating and quenching or by controlled cooling per the alloy; the wrong anneal leaves the panel too soft or too hard.

Corrosion protection is restored after metal finishing: epoxy primer on bare steel, seam sealer at joints and cavity wax inside sections.

MIG welding sheet steel: a push angle of 10–15°, a short arc and a stitch or backstep sequence control heat input and distortion.

Squeeze-type spot welding requires clean mating surfaces and a correct electrode tip; a worn tip increases resistance and produces a weak weld.

Weld-through primer is applied only at the mating flange and must be dry before welding; a heavy coat contaminates the weld.

Structural adhesive bond strength depends on surface preparation, bond gap and cure; a contaminated or uneven surface fails the joint.

MIG brazing is used on galvanised and high-strength steel where fusion welding would damage the coating or the microstructure.

Aluminium TIG welding uses AC current and a dedicated tungsten electrode; the oxide layer is removed by the AC cleaning action and by mechanical cleaning.

Weld inspection includes visual check for porosity, undercut and incomplete fusion, plus destructive test coupons for critical joints.

Brazing flux residue is removed with hot water and a brush; left in place it causes corrosion under the paint.

Filler is mixed on a clean, non-porous board; a wooden or cardboard mixing board absorbs hardener and contaminates the mix.

The hardener ratio is measured by weight or by a calibrated dispenser; a coloured hardener shows incomplete mixing as streaks.

Filler is applied with a flexible spreader in a criss-cross pattern to avoid trapping air; a thick single pass traps air and causes pinholes.

A fibreglass-reinforced filler is used over repaired metal or where extra strength is needed; it is not a substitute for structural repair.

Filler is sanded with a block, not by hand alone; a block follows the panel's contour and prevents waves.

Guide coat on filler shows low spots; the filler is built up in thin layers until the guide coat sands evenly.

Filler must be fully cured before sanding; sanding uncured filler clogs the paper and leaves a smeared surface.

Filler over paint requires the paint to be abraded and cleaned; filler over a glossy or waxed surface will not adhere.

Grit sequence for bare steel and filler: 40–80 for shaping, 120–180 for levelling, 240–320 for primer preparation, 400–600 for basecoat blending.

A random orbital sander with a soft interface pad follows panel curvature; a hard pad on a curved panel produces flat spots.

Wet sanding is used on cured primer and clearcoat; the paper is kept wet and the surface is flushed and dried before the next coat.

Abrasive type matters: aluminium oxide for general use, silicon carbide for wet sanding and clearcoat, and ceramic for fast cutting on hard primers.

Surface cleaning uses a wax and grease remover applied with one cloth and wiped dry with another; a single cloth spreads contamination.

Masking tape is pressed down at the edges to prevent solvent bleed; a loose edge allows paint to creep under the tape.

Sanding dust is removed with a tack rag and compressed air before paint; dust in the booth causes dirt nibs in the finish.

Blending solvent is applied to the edge of the new paint to melt it into the old finish; it is not a thinner for the topcoat.

Pot life shortens as temperature rises; a mixed 2K product left in a warm booth may gel before use.

Mixing by weight is more accurate than by volume for small quantities; a scale with 1 g resolution is used for small batches.

Gun inlet pressure is set with the trigger pulled and the air flowing; a static reading with the trigger released is too high.

A spray pattern test shows a dry centre or split pattern caused by a blocked nozzle or a worn needle; the gun is cleaned or rebuilt.

Basecoat is applied in thin, even coats to a hiding film; a heavy coat of metallic causes mottling and runs.

Clearcoat is applied wet-on-wet within the flash-off window; too long a delay causes poor intercoat adhesion.

Booth balance: supply air and exhaust air are balanced to maintain a slight positive pressure and a uniform airflow across the work.

Gun cleaning uses the correct solvent for the product; a waterborne gun is not cleaned with solvent-based thinner.

Dirt nibs are particles trapped in the paint; they are removed by sanding and polishing, and the source (booth, clothing, masking) is corrected.

Pinholing in filler or primer is caused by trapped air or solvent; it is filled with a thin putty or a primer-surfacer and sanded.

Adhesion failure (peeling) follows poor surface preparation, contamination or an incompatible product; the affected area is stripped and recoated.

Solvent pop is prevented by correct flash-off and film build; once present, it is sanded out and recoated.

Colour mismatch after repair is corrected by blending or by re-matching the variant; a panel painted to the code alone may not match a faded vehicle.

Clearcoat peeling on older vehicles is often a manufacturer defect or UV degradation; the repair is stripping and recoating, not polishing.

Metallic mottling is corrected by a uniform application and a blender; a heavy coat of metallic flake settles unevenly.

Defect diagnosis follows the sequence: identify the defect, find the cause, correct the cause, then repair the finish.

A spectrophotometer reads the colour at several angles and gives a variant match; the reading is confirmed with a spray-out card.

A spray-out card is compared with the vehicle in natural light and at different angles before the panel is painted.

Blending a metallic requires the basecoat to be applied over the blend area with a blender; the clearcoat then covers the whole panel.

Polishing sequence: compound with a wool or foam pad, then polish with a finer pad, then protect with wax or sealant.

A rotary polisher generates heat; too much heat burns the clearcoat, and too much pressure leaves holograms.

Paint edges at gaps are finished with a fine brush or a spray-out card to avoid a hard edge that peels.

Colour match is judged against the adjacent original panel, not against a colour chip or a computer screen.

Warranty on a paint repair covers adhesion and colour match within the manufacturer's tolerance; the customer is told the tolerance.

Urethane windscreen adhesive has a safe-drive-away time; the vehicle is not released before that time, and the customer is informed.

The glass bonding surface is primed with a glass primer and a body primer; the wrong primer causes adhesive failure.

Trim clips are matched to the panel; a wrong clip leaves a gap or a rattle, and a missing clip causes a buzz.

Electrical connectors have locking tabs and seals; a connector is released by the tab, and a damaged seal is replaced to prevent water ingress.

Driver-assistance sensors are calibrated after windscreen replacement, suspension work or a change in ride height; the calibration is recorded.

Water leak testing uses a controlled spray for a set time; the leak is traced to the seal or the body seam, not assumed.

Final assembly includes a function test of lights, wipers, windows, locks and the audio system; a fault is corrected before delivery.

The pre-delivery inspection records gaps, finish, cleanliness and function, and the customer signs acceptance.

The estimate is built from the damage assessment: parts, labour operations, paint materials, sublet and consumables, each with a price and a time.

Labour operations are taken from the manufacturer's or industry labour guide; overlapping operations are identified and not double-charged.

A supplementary estimate is raised when hidden damage is found; the customer authorises it in writing before work continues.

The job card records the vehicle, complaint, authorised work, parts, technician time and sign-off; it is the record of the contract.

Paint and materials are charged by a materials schedule or a percentage of paint labour, per the agreed method.

Customer care includes a clear explanation of scope, time, warranty and cost, plus a written record of the conversation.

Records are retained per the jurisdiction's requirements: estimate, authorisation, job card, parts invoices and paint mixing records.

A quality control check before delivery compares the repair with the estimate and the original condition; the customer signs off.

Isocyanate-containing 2K products require supplied-air respiratory protection; cartridge masks do not protect against isocyanates.

Flammable liquids with a flash point below 23 °C are stored in approved cabinets and decanted with bonding and earthing.

Booth face velocity is measured and logged; a drop below the specified value means the booth is not safe for spraying.

Sanding dust is controlled with extraction and wet methods; dust is a respiratory and explosion hazard.

Waste is segregated: solvent and paint sludge as hazardous waste, metal and cured paint solids separately.

Noise above 85 dB(A) requires hearing protection and audiometric testing.

The hierarchy of control is applied: substitution, engineering controls, administrative controls, then PPE.

Safety data sheets are accessible for every product, and staff are trained in their use.

Hammers are matched to the task: flat for planishing, pick for raising and shrinking, slapper for large curved panels.

Dollies are matched to the hammer face and the panel curvature; a heel dolly supports off-dolly work.

A body file reveals high and low spots; a flexible file follows curvature and a rigid file shows flatness.

A slide hammer pulls dents through a stud or screw; the pull direction is opposite the deformation.

Air sanders are selected by orbit size and type; a random orbital action reduces pigtails.

Spray gun fluid tip size is matched to the material: 1.2–1.3 mm for basecoat and clearcoat, 1.4–1.6 mm for primer.

Compressed air is dried and filtered; moisture causes paint defects and shortens tool life.

Torque values come from the manufacturer's data; a torque wrench is calibrated and used correctly.

A unitised body is load-bearing; a body-over-frame design carries load in a separate chassis.

Crumple zones absorb energy, and the safety cage resists deformation; structural repair affects crash performance.

HSS and UHSS are common in pillars and sills; heat and repair methods are restricted by the manufacturer.

Aluminium requires isolation from steel to prevent galvanic corrosion and uses dedicated rivets and adhesives.

SPR, blind rivets, flow-drill screws and structural adhesives join aluminium and mixed-material bodies.

Torque-to-yield bolts are single-use and are replaced after loosening.

Plastic and composite panels are repaired with plastic welding or two-part adhesives, identified by the plastic code.

Corrosion protection is restored at every repair: zinc-rich primer, seam sealer, cavity wax and anti-chip coating.