Paint & paint systems
- Paint composition
- Generic types of paint
- Paint systems
- Application equipment
- Application techniques
- Paint defects
- Calculations
- Technical data sheet
- Metallic coating-thermal spray
- Metallic coating-hot dip galvanizing
- Fire protective coatings
- Special coatings
- IOGP Definitions of Paint and Surface Treatment
Calculations
Introduction
Which calculations need to be done?
A certified coating advisor is expected to carry out simple calculations related to the coating operation, like:
- WFT vs. DFT and vice versa
- Solid content after thinning
- Volumes required for specific jobs
- Spreading rates
- Consumptions
- Simple cost calculations
Calculations during exam
- Formulas required for calculation will be handed out
- Formulas may have to be rearranged for a particular calculation
- Other data required will be given, or must be found by the candidate in technical information provided
- Basic formulas for area calculation will not be given
Technical data
- Most of the product data needed for carrying out inspections and for necessary calculations are found in Technical Data Sheets (TDS)
- Some data may also be found in Safety Data Sheets (SDS)
TDS data used for inspections & calculations
Corresponding DFT & WFT
- Minimum
- Maximum
Physical properties
- % Volume solids
- Flash point
- VOC
Surface preparation
- On various substrates
Application requirements
- Ambient conditions
- Methods
Application Data
- Mixing ratio
- Induction time
- Pot life
- Thinner No.
- Airless spray data
- Thinning restrictions
Drying times
- At various temperatures
Typical system
- coats
- DFT
Pack size
Abbreviations used in formulas
WFT = Wet Film Thickness
DFT = Dry Film Thickness
% VS = Percent Volume Solids
LF = Loss Factor
DV = Dead Volume
Formulas to be used during exam
Formulas
Simple practical formula
1 : 1 : 1000 paint quantity (ltr) : Area (m2) : WFT (micr.)
Meaning
1 ltr paint cover 1 m2 in 1.000 µm WFT
1 ltr paint cover 10 m2 in 100 µm WFT
Formula for determining the DFT
| WTF | |
| % VS | |
| DFT |
Formula for determining the WFT
| DFT | |
| % VS | |
| WFT |
Formula for determining the WFT after thinning
| DFT | |
| % thinner | |
| % VS | |
| WFT |
Theoretical spreading rate
| % VS | |
| DFT | |
| m2/litre |
Consumption of paint, no loss (theoretical)
| Area (m2) | |
| DFT | |
| % VS | |
| Consumption |
Consumption of paint, with loss (practical)
| Area (m2) | |
| DFT | |
| % VS | |
| Loss Factor | |
| Consumption |
Dead volume paint consumption
Dead Volume: increases paint consumption
Smooth steel surface: Even film thickness, No dead volume
Uneven steel surface: Paint will fill the valleys in the profile, called “Dead Volume”
Dead volume and surface profile
- Higher surface profile increases dead volume
- The dead volume will be filled, and will increase the consumption of primer
- The dead volume consumption of primer comes in addition to the consumption for the primer coat in the specification
- The other coats will not be influenced by dead volume
- DV will on exam be given as ml/m2 or as l/m2
Dead volume paint consumption
| Area (m2) | |
| DV | |
| % VS | |
| Loss Factor | |
| Dead volume paint consumption |
- Gå til avsnitt
- Introduction
- Formulas to be used during exam
- Simple practical formula
- Formula for determining the DFT
- Formula for determining the WFT
- Formula for determining the WFT after thinning
- Theoretical spreading rate
- Consumption of paint, no loss (theoretical)
- Consumption of paint, with loss (practical)
- Dead volume paint consumption
