Red Seal Auto Body Technician cheat sheet

WHMIS 2015/GHS labels use six required elements: product identifier, supplier identifier, pictogram, signal word, hazard statement, and precautionary statement.

A substance is 'hazardous' under WHMIS if it meets any GHS physical, health, or environmental hazard criteria adopted in the Canadian Hazardous Products Regulations.

Isocyanate hardeners (paint, foam, adhesives) are respiratory sensitizers: exposure limits are set as ceiling or STEL values; supplied-air or air-purifying respirators with organic vapour/P100 cartridges are required below IDLH.

Air-purifying respirators do not supply oxygen; atmosphere-supplying respirators are required in oxygen-deficient or IDLH atmospheres (e.g., confined spray booths, tanks).

Flammable liquids are classified by flash point; a Class IB liquid has a flash point below 22.8 C and boiling point at or above 37.8 C.

A fire extinguisher selection rule: Class A (ordinary combustibles) water/foam; Class B (flammable liquids) CO2, dry chemical, or foam; Class C (energized electrical) non-conductive agents; Class D (combustible metals) special dry powder.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Noise exposure limit under most Canadian jurisdictions is 85 dBA for an 8-hour equivalent; a 3 dB increase halves permitted exposure time.

Ergonomic lifting rule: keep load close, bend knees, avoid twisting; NIOSH lifting equation recommends keeping the load constant below 23 kg (51 lb) for ideal lifts.

Body-on-frame: separate ladder frame carries load; body panels are non-structural. Unibody: stamped panels welded into a stressed shell; rockers, aprons, and rails carry load.

High-strength steels: HSS (approx. 300-700 MPa tensile), AHSS including DP (dual phase), TRIP, martensitic (up to ~1500 MPa), and boron/martensitic ultra-high-strength steels used in B-pillars, rockers, and bumper beams.

Boron/ultra-high-strength steel (UHSS) parts are typically not repairable by heat; OEM procedures often require replacement because heat above ~600 C destroys the martensitic microstructure.

Aluminum body structures require dedicated tools, isolation from steel to prevent galvanic corrosion, and rivet-bonding (self-piercing rivets plus structural adhesive) rather than spot welding.

Galvanic corrosion occurs when dissimilar metals contact in the presence of an electrolyte; the more anodic metal (e.g., aluminum against steel) corrodes.

Bake-hardening steels gain strength during paint oven cure; repair heat must stay below OEM limits to avoid over-aging or softening.

Section modulus and moment of inertia describe a rail's bending stiffness; crush initiators and triggers are designed to fold predictably in a collision.

Magnesium and carbon-fibre components require OEM-specific repair; carbon fibre is bonded and riveted, never welded.

Seam sealers, structural adhesives, and hem flanges contribute to stiffness; removing them without replacement reduces crash performance.

Repair vs replace rule: replace when the panel cannot be restored to pre-accident shape/strength within OEM limits, when access for repair is impossible, or when repair cost exceeds replacement.

Estimating labor is expressed in body labor hours (BLH) and paint labor hours (PLH); refinish time is calculated from OEM/industry refinish time guides, not from body time.

Betterment/depreciation applies to worn parts (tires, batteries, prior damage); it reduces the settlement for wear unrelated to the loss.

Diminished value is the loss of market value after a properly repaired vehicle; it is separate from the cost of repair.

Supplement requests must document hidden damage with photos, measurements, and OEM procedures; insurers require authorization before additional work.

Total loss threshold: when repair cost plus salvage value exceeds actual cash value (ACV), the vehicle is typically declared a total loss (thresholds vary by jurisdiction).

A damage report should record: point of impact, direction of force, energy path, related/unrelated prior damage, and structural measurements.

Paint material cost is estimated from refinish hours times a materials rate, or from a paint/materials percentage applied to refinish labor, per the estimating system.

Photo documentation standards: overall shots, mid-range, close-ups with scale reference, and VIN/odometer images for every estimate file.

Panel straightening uses a hammer and dolly: the dolly is held behind the low spot and the hammer strikes the high spot to stretch/level the metal.

Off-dolly (hammer on-dolly) technique: dolly supports the panel from behind while the hammer strikes the opposite side, planishing and stretching the metal.

Heat shrinking: heat a small area to a dull red (approx. 600-700 C for mild steel) and quench with a wet rag or shrinking hammer to remove stretched metal.

A pick hammer and file or a body file reveal high and low spots; a straight edge and tram gauge check panel alignment.

Panel gap tolerances are typically 3-6 mm; check gaps before and after repair to confirm fit.

Adhesive bonding and hem flanging are used on aluminum and some steel closures; the hem flange must be sealed to prevent corrosion.

When replacing a panel, follow OEM sectioning locations; do not cut through high-strength steel reinforcements or at stress risers.

Spot weld removal: drill or use a spot-weld cutter through the weld nugget only; avoid damaging the underlying panel.

MIG brazing (silicon bronze) is used on high-strength steel outer panels to limit heat input and preserve coating.

Frame/structural measurement compares datum points and control points to OEM specifications; tolerance is usually +/-3 mm unless OEM states otherwise.

Three-dimensional measuring systems compare length, width, and height; a tram gauge measures only length and diagonal.

Pull direction must oppose the impact direction; use multiple pulls and re-measure after each pull to avoid over-pulling.

Anchoring: vehicle must be secured at OEM-specified anchor points; never pull from suspension or drivetrain components.

Heat on structural rails is limited; OEM procedures often prohibit heat on UHSS and restrict temperature on HSS (commonly below ~600 C).

Sectioning of structural rails is allowed only at OEM-approved locations, with proper backing plates and weld procedures.

Squaring: measure the diagonal of the frame/body openings; equal diagonals indicate a square structure.

After structural repair, verify suspension mounting points, wheel alignment, and panel gaps; document before/after measurements.

Replacement of structural components requires restoring corrosion protection (weld-through primer, cavity wax, seam sealer) per OEM.

GMAW (MIG) settings depend on material thickness, wire diameter, and shielding gas; ER70S-6 wire with 75% Ar/25% CO2 is common for mild steel.

Squeeze-type resistance spot welding (STRSW) is the OEM-preferred method for joining high-strength steel panels; verify weld nugget diameter and tear-out.

Plug welds replace factory spot welds in non-accessible areas; hole diameter should be roughly equal to or slightly larger than the original nugget.

MIG brazing uses silicon-bronze wire and lower heat input; it is not a fusion weld and must not be used where OEM requires fusion.

Aluminum requires AC TIG or push-pull MIG with dedicated wire, argon shielding, and stainless brushes to avoid contamination.

Welding galvanized or zinc-coated steel produces zinc oxide fumes; remove coating near the weld zone and use ventilation/respiratory protection.

Weld-through primer is applied to mating surfaces before welding to protect the joint; it must be compatible with the welding process.

Oxy-acetylene cutting is generally not permitted on structural or high-strength components; plasma cutting is used for non-structural sheet.

Post-weld inspection includes visual check for porosity, undercut, spatter, and verification of weld size and penetration.

Surface prep sequence: wash, remove wax/grease with a wax and grease remover, sand, clean again, then apply primer/filler.

Grit selection: 80-180 for stripping and shaping filler, 220-320 for primer sanding, 400-600 for sealer/primer surfacer, 800-1500 for blending.

Body filler (polyester) is applied over bare metal or epoxy primer, never directly over lacquer, enamel, or OEM e-coat without proper prep.

Filler thickness should be minimized; deep dents are straightened first, filler used only to level minor imperfections.

Guide coat (contrast spray or powder) reveals low spots during block sanding.

Epoxy primer provides corrosion protection and adhesion; apply to bare metal before filler or as a sealer.

Primer surfacer fills sand scratches; it must be sanded and sealed before topcoat.

Sand scratches: finer grit removes coarser scratches; never jump more than one grit step (e.g., 180 to 320).

Cleanliness: use tack cloths and dedicated clean areas; silicone contamination causes fish eyes.

Paint system layers: e-coat (OEM), primer/sealer, basecoat (colour), clearcoat (protection).

Two-component (2K) products require accurate mix ratios by volume; use a mixing stick and graduated cup.

Pot life is the usable time after mixing; exceeding it causes poor cure and adhesion failure.

Spray gun setup: fluid tip size depends on material (approx. 1.3-1.4 mm for basecoat, 1.4-1.5 mm for primer); adjust pattern and pressure per gun data sheet.

Flash-off time is the wait between coats; insufficient flash causes runs and solvent popping.

Baking/curing temperatures are per product data sheet; typical low-bake is 60 C for 30 minutes.

Colour match: verify spray-out panel under the same lighting; use blending within panels to hide metallic mismatch.

Orange peel is caused by insufficient atomization, incorrect reducer, or too-fast application; runs are caused by over-application.

HVLP guns improve transfer efficiency (typically 65-85%) and reduce overspray compared with conventional guns.

Urethane windshield adhesive requires primer and a minimum drive-away time specified by the adhesive manufacturer (often 1-4 hours depending on product and conditions).

Windshield glass is a structural component on modern vehicles; it contributes to roof crush and airbag deployment support.

Safe drive-away time depends on temperature and humidity; cold or humid conditions extend cure time.

Moulding clips and fasteners are single-use in many cases; replace damaged clips to avoid water leaks and rattles.

Side and rear glass may be bonded or set in rubber; check OEM for bonding vs gasket.

ADAS cameras and sensors mounted to the windshield require recalibration after glass replacement; follow OEM static or dynamic calibration procedure.

Interior trim removal uses plastic trim tools; metal tools damage clips and substrates.

Airbag-equipped seats and pillars: disconnect battery and wait the OEM-specified time before working near airbags.

Water leak diagnosis: use water test with a helper inside; check cowl, sunroof drains, and body seams.