Paint Analysis

Question 1

What is paint?

Answer 1

A suspension of pigments and additives intended to colour or protect a surface

Question 2

What is a pigment?

Answer 2

• A fine powder that is insoluble in the medium in which it is dispersed
• The granules do not dissolve and remain intact and are dispersed evenly across the surface
• Pigments are intended to colour/cover a surface -> may be organic, inorganic or a mixture

Question 3

What is a binder?

Answer 3

A component that helps distribute the pigment on a surface

Question 4

What is the vehicle?

Answer 4

Refers to the solvents, resins and other additives that form a continuous film binding the pigment to the surface

Question 5

How is paint evidence used?

Answer 5

• Match paint chips physically -> shape of chip, microscopic evidence of number and thickness of layers
• Colour and texture
• Chemical analysis -> inorganic and organic compounds, metallic finish, polymer primer coat

Question 6

What are the 4 separate coatings on automobile paint?

Answer 6

1. Pretreament/electrocoat: typically zinc electroplating is applied to the steel body of the vehicle to inhibit rust
2. Primer: epoxy resin with corrosive resistant pigments
3. Topcoat: colour
4. Clear coats: unpigmented coatings applied to improve gloss and durability