2 Paint: binder, pigments and additives suspended in a solvent Major ComponentsBinderPigmentExtendersModifiers
3 BinderPolymer (vehicle) that holds paint components together, forming a hard surface film as solvent evaporatesLacquer (evaporation of organic solvent)Enamel (chemical reaction of components)Latex (evaporation of water)Architectural
5 Automotive Paint Layers Electrocoat Primer on bare steel bodyCorrosion resistance, black, grayPrimer Surfacer smoothes imperfectionsIncreases adhesion of basecoat to primerPigment added to minimize color contrast between primer and basecoatBasecoat /Color CoatPigments, aluminum flakesClear CoatModifiers for durability, UV resistance
6 Paint as Physical Evidence Hit and Run/MVAs- Paint fragments or smears transferred to clothing (pedestrian) or another vehicle (vehicle to vehicle)Burglaries- Paint smears transferred onto a tool or point of entry (tool mark)
8 Scrape down clothing for Trace Evidence An efficient and effective method of recovering very small paint and glass particles from the clothing of Hit and Run victims, is the “Shake and Scrape” Method. A garment is shaken and scraped with a large spatula over a large sheet of paper to collect any loosely adhering trace particles, especially paint particles from vehicles involved in Hit and Runs.
15 Microscopic Examination of Paint Stereomicroscope or Comparison MicroscopePhysical CharacteristicsColorSurface TextureNumber of layersColor sequence of layersThickness of layers
16 ClearcoatBasecoat/ ColorcoatPrimer SurfacerElectrocoat Primer
17 Chemical/Instrumental Analysis of Paint Chemical AnalysisSolubility testsPyrolysis GC- decomposes paintIR MicrospectrophotometryIR absorption spectrum for each layerSEM-EDX or X-Ray Fluorescence (elemental composition)
23 Investigative Information Paint Data Query (PDQ)Database of Chemical & Color Information of Original Automotive Paints (>13,000 vehicles)Upload IR spectra from Q sampleReceive:Make (Toyota, Ford, Chrysler, Chevy)GM- Chevy, Buick, Pontiac, CadillacModel (Corolla, Mustang, Sebring, Malibu)Corolla, Camry, SolaraYears of production
26 Paint Evidence Collection Collect entire item, if possibleTools, clothing, bicycle, vehicleVehicle to vehicle transferAll layers of contactContainersPaper fold into envelopeVial (glass, plastic)Small cardboard box (larger paint chips)Keep paint chips intactJigsaw match sometimes possible
27 Paint Evidence Collection Known/Reference SampleClean scalpel or knife bladeRemember possibility of Jigsaw MatchNear area of damage down to bare metalNear area of toolmark impressionPackage separately, note location
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