Craftsman Motor Vehicles Body Repair flashcards

35 cards. Read the term and the definition here. The deck at the top of this page is optional.

Isocyanate respiratory protection

Urethane paints and clears contain isocyanates that can cause permanent sensitization. Spraying requires a supplied-air respirator; dust masks and cartridge masks are not adequate for isocyanate exposure.

Grade D breathing air

Compressed air used for supplied-air respirators must meet Grade D purity for oxygen, dew point, carbon monoxide, and oil. Shop air lines must never feed a respirator directly.

Hybrid high-voltage disable

Before cutting, welding, or straightening near orange high-voltage cables, de-energize the system per OEM procedure and wait the specified time for capacitors to discharge.

Silicone contamination fish-eye

Silicone sprays and tire dressings migrate through the air and cause fish-eye craters in paint. Keep them out of prep and spray areas and use a dedicated wax and grease remover.

Unibody load path

In a unibody, stamped panels and rails form a stressed shell. Impact energy travels along load paths, so damage often appears far from the impact point as kinks or gap changes.

UHSS heat restriction

Ultra-high-strength and press-hardened boron steels lose strength when heated. OEM procedures prohibit torch shrinking or heat straightening; repair by sectioning at approved locations or replacement.

Aluminum galvanic isolation

Aluminum panels corrode when steel dust or bare steel contacts them. Use dedicated aluminum tools and abrasives and isolate the two metals to prevent galvanic pitting.

Supplement documentation

Hidden damage found after teardown requires a written supplement with photos and approval before repair continues. Verbal approval alone does not protect the shop or the customer.

Work order essentials

A work order records VIN, mileage, keys received, pre-existing damage photos, customer authorization signature, and payment or insurance details before work begins.

Total loss threshold

A vehicle is typically declared a total loss when repair cost plus salvage value exceeds a set percentage of actual cash value. State rules and insurer formulas vary.

Overlap labor billing

When operations share time, such as refinishing a panel removed for body repair, the estimate must document the overlap so the same labor is not billed twice.

Spot weld removal

Grind to reveal the weld, center-punch, then drill or use a spot-weld cutter. Separate the panel with a chisel to avoid distorting the surrounding metal.

Panel gap tolerance

Door, hood, and fender gaps are typically set to 3–5 mm and must be even front-to-back and top-to-bottom. Adjust hinges and shims before tightening the striker.

Hinge adjustment order

Set the rear gap first, then the front gap, then height. Adjust the striker last so the latch engages without preload that twists the door.

Plug weld pitch

Replacement panels are attached with plug welds spaced about 25–40 mm apart, matching the original spot weld pattern. Clamp tightly and weld from the center outward.

Heat shrinking steel

Heat a small spot to cherry red, about 650–700 °C, then quench with a damp rag or hammer on-dolly while hot. The metal contracts and removes the stretched high spot.

Hammer on-dolly vs off-dolly

Hammer on-dolly planishes and stretches metal for finishing. Hammer off-dolly, with the dolly behind the low spot, raises a depression and is used for roughing out.

Pick and file method

A body file cuts only high spots, so file marks show where to shrink. Use it across the repair to reveal high and low areas before applying filler.

Body filler thickness limit

Polyester filler is cosmetic and typically limited to about 3 mm (1/8 in). Deeper damage must be metal-straightened or replaced before filler is applied.

Plastic substrate identification

The ISO code molded on the back of a plastic part identifies PP, TPO, ABS, or PC. TPO and PP need a specialty adhesion promoter and flexible filler for repair.

SMC repair taper

For SMC or fiberglass, grind a taper about 25 mm (1 in) wide around the damage, laminate with resin and mat, then seal with epoxy primer before filler.

Filler mixing ratio

Incorrect hardener ratio leaves filler soft, sticky, or shrinking. Measure by weight on a scale or with the supplied stick and respect the product's pot life.

Squeeze-type spot welding

STRSW is the OEM-preferred method for structural panels. Verify settings with a test coupon and peel test before welding the vehicle, and follow the OEM weld schedule.

Sectioning joint placement

Sectioning joints must follow OEM procedures and be placed outside crush zones and non-section areas. A butt joint with a backing plate or offset lap joint is typical.

Aluminum welding setup

Aluminum requires AC TIG or push-pull MIG with dedicated wire, liner, and a stainless brush. Steel tooling contaminates the weld and causes porosity.

Structural adhesive bonding

Structural adhesive needs clean, dry, bare metal, a specified bond gap, and full clamp time. Combining adhesive with welding is allowed only where OEM procedures approve.

Pull direction and re-measure

Pull opposite the impact direction in small increments, re-measuring after each pull. Over-pulling stretches rails and makes return to OEM dimensions harder.

Datum and centerline

A 3D measuring system establishes datum and centerline reference points. Record dimensions before pulling and after repair to confirm the structure returned to OEM specifications.

Frame rack chain safety

Use rated chains and clamps anchored at OEM clamping points. Never stand in line with a loaded chain, and keep clear of chains under tension during a pull.

Wax and grease removal

Use a two-rag method with wax and grease remover before sanding and again before priming. Sanding contaminated paint drives contaminants into the surface and causes adhesion failure.

Guide coat purpose

Aerosol or powder guide coat over primer surfacer reveals low spots and sand scratches during block sanding. Sand until the guide coat is gone and the surface is uniform.

Blending basecoat and clear

Apply base with a blender or reduced edge into adjacent panels to hide the color transition. Keep the clear blend within a natural break such as a body line or panel edge.

Urethane windshield adhesive

Urethane-set windshields are structural and contribute to roof crush and airbag performance. Use only OEM-approved urethane and observe the specified drive-away time.

Laminated vs tempered glass

Laminated windshields crack and can be resin-repaired if damage is outside the driver's primary vision area. Tempered side and rear glass shatters into cubes and cannot be repaired.

SRS battery disconnect

Disconnect the battery and wait the OEM-specified time before working near airbags. Never probe SRS circuits with a test light; use a proper scan tool.