Coating Fundamentals Flashcards
A coating must exhibit a variety of properties to fulfill it’s role in corrosion control. Desirable properties include:
Chemical Resistance, Water Resistance, Ease of Application, Adhesion to Substrate, Cohesive Strength, Flexibility and Elongation, Impact Resistance, Temperature Resistance, and Dielectric Strength.
During coating formulation there is usually a ___-__ made among desirable properties.
Trade-off
The desirable properties of a coating alter when the ___ of the coating are changed.
Components
Coatings are classified as?
Organic or Inorganic
Most industrial and marine coatings are?
Organic Coatings.
Organic coating binders are made fro once living things. Most coatings now come from?
Refined Petroleum products.
All organic coatings contain?
Carbon
Inorganic coatings use inorganic binders, most commonly based on ___ or ___.
Silicone or Silicates.
Metallic Coatings (e.g. metallizing and galvanizing coatings) are?
Inorganic
Broadly speaking, the major difference between organic and inorganic coating is?
Heat resistance.
Organic coatings have less resistance to heat because of the relative weakness of the ___-___-___ bond.
Carbon-to-carbon bond.
Liquid-applied coating components are characterized by the terms?
Pigment
Resin/Binder
Solvent
Vehicle
A discrete particle solid used to impart specific properties to the coating in the liquid and solid state?
A Pigment
Pigments do not ___ in the coating and they serve multiple functions.
Dissolve
Pigments may be used to?
Impart Color, Protect the bider from weathering, provide inhibitor protection, control water resistance, provide a form of cathodic protection, or modify the mechanical or electrical properties.
The vehicle contains the?
Resin and Solvent
A coating consists of the?
Pigment and vehicle.
Additives are most commonly ___ ___ of a coating added in small amounts to perform a specific function.
Liquid components of a coating.
There are thousands of ___ and new ones presented frequently. These give each individual product its unique characteristics.
Additives
These give each individual coating product its unique characteristics.
Additives
Some additives keep the coating from settling, reduce foaming, retard color float and/or build thixotropy. These can all be described as?
Ensuring coating stability.
Additives may aid the coatings application by improving ___ ___ and wetting which, in turn, increases ___ ___ and decreases ___.
Flow out and wetting which, in turn, increases pot life and decreases sag.
Additives can aid in ___ Resistance.
UV Resistance.
Additives can increase/decrease?
Gloss
Additives can prevent ___ over in the can.
Skinning
Additives can retard or speed up?
Curing
Additives can increase shelf life. True or false?
True
Additives may also be considered a ___ ingredient.
Secret
The 1___ is the backbone of the coating ans supplies most 2___ ___ features and functions of the material.
Binder
Heavy Duty
A coating typically gets its name from the?
Binder
Epoxies, polyurethanes, alkyds, acrylics, etc are all?
Binders.
Multiple binders can be combined in a coating? True or False?
True
To create a protective film on a substrate the binder resins must convert from a ___ to a ___ state that adheres to and protects the surface.
Liquid to a Solid.
The liquid state of a coating allows for?
Application
In order to be suitable for use in a corrosion protection system in the industrial and marine environment, the binder should?
Have good wetting and adhesion properties.
Resist transmission of water, oxygen, and other chemical species.
Tolerate a variability in the application process.
Resist chemical and physical changes in the service environment.
Dry within an acceptable period.
Form a stable film that maintains it’s characteristic properties.
Strength, hardness and flexibility are all examples of possible ___ ___ of a coating.
Characteristic properties.
Some of the resins used as binders are ___ at normal temperatures.
Solids.
___ are added to liquefy the binder and allow for application.
Solvents.
Solvents have two major characteristics that influence their use in protective coatings.
Solvency Power & Volatility.
The ability to dissolve the resin is know as?
Solvency Power
___ governs the evaporation rate of a solvent.
Volatility
Once applied and cured ___ serve no purpose in a coating.
Solvents
___ may cause performance problems if they remain in the coating film.
Solvents
Because of environmental legislation, coating users and manufacturers are actively researching technologies to ___ or ___ the need for solvents.
Reduce or Eliminate.