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Calculations

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Calculations : PaintAbbreviations

WFT = Wet Film ThicknessDFT = Dry Film Thickness% VS = Percent Volume SolidsLF = Loss FactorDV = Dead Volume

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Example:

WFT = 250 m

% VS = 50 %

DFT = = 125 m

WFT x % VS 100

250 x 50 100

Formula for determining the DFT

Formula: DFT =

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Formula for determining the WFT

Example:

DFT = 100 m % VS = 65 %

WFT = = 154 m

DFT x 100 % % VS

100 x 100 % 65 %

Formula : WFT =

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Example: DFT = 100 m % VS = 65 %Added thinner = 20 %

WFT = =185 m

DFT x (100 % + % thinner) % VS

100 x (100 % + 20 %) 65 %

Formula for determining the WFT after thinning (Method 1)

Formula: WFT =

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Formula for determining the WFT after thinning (Method 2).

DFT = 100 microns% VS = 65 %Added thinner = 20 %Volume of paint = 1 litre New % VS: = 54 %Volume of thinner = 0,2 litreNew volume = 1,2 litre

WFT = = 185 m

651,2

100 % x 100 microns54 %

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Theoretical spreading rate

DFT = 100 microns% VS = 6510 = Factor

= 6,5m2/litre

% VS x 10DFT

65 x 10 100

= m2/litreFormula:

Spreading rate:

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Consumption of paint, no loss (1 of 2)

Paint DFT % VSEpoxy mastic 200 microns 85 %Polyurethane topcoat 50 50 %

Consumption = = litreArea (m2) x DFT

10 x % VS

To be painted: Tank, area of 500 m2

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Consumption of paint, no loss (1 of 2)

Epoxy mastic = 117,7 litre

Polyurethane topcoat = 50,0 litre

500 x 20010 x 85

500 x 5010 x 50

To be painted: Tank, area of 500 m2

Formula: Area, m2 x DFT10 x % VS

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Consumption of Paint with loss

Epoxy mastic = 196 litre

Polyurethane topcoat = 83 litre

500 x 20010 x 85 x 0,6

500 x 5010 x 50 x 0,6

To be painted: Tank, area of 500 m2 , 40 % loss

40 % loss implies that only 60 % will remain on the surface. The correction factor, Loss factor, will be 0.6

Formula: Area, m2 x DFT10 x % VS x Efficiency

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Consumption of paint with loss including Dead Volume (1 of 2)

Total Dead volume, litre = Area (m2) x DV x 100% VS x Eff

Roughness, microns3045607590

105

Dead volume, l/ m2 0.020.030.040.050.060.07

A certain roughness will give a certain dead volume

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Dead volume increases the volume of paint required

Steel

Smooth (polished) steel surfaceEven film thickness

Steel

Uneven steel surfacePaint will fill the valleys

Specified thickness

Dead volume

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How much paint should we order ? calculation of paint consumption with

loss

Example: 100 litre is needed, loss is 40 %We have to order

= = 167 litre

Not 100 litre + 40 % extra = 140 litre

100 x 10060

1000,6 (Efficiency)

A loss of 40 % means that only 60 % will be applied on the surface

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DFT % VSEpoxy mastic 200 85Polyurethane topcoat 50 50

Litre dead volume = = 39 litre (EM)

Epoxy mastic (EM) = 196 litre (EM)

Polyurethane topcoat = 83 litre (PU)

500 x 0,04 x 10085 x 0,6

500 x 20010 x 85 x 0,6

Consumption of paint with loss including Dead Volume (2 of 2)

500 x 5010 x 50 x 0,6

Tank area 500 m2, 40 % loss, surface roughness 60 microns

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Consumption of Paint with loss

Jotamastic 87 Dft :200 Mic Volume solid 87%

Hardtop As Dft : 50 Mic Volume solid 50%

To be painted: Tank, area of 1500 m2 , 30 % loss

Dicat dengan:

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Consumption of Paint with loss

Jotamastic 87 = litre

Hardtop AS = litre

To be painted: Tank, area of 1500 m2 , 30 % loss

Cari quantity

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Consumption of Paint with loss

Jotamastic 87 = 492.61 litre

Hardtop AS =214.29 litre

1500 x 20010 x 87 x 0,7

1500 x 5010 x 50 x 0,7

To be painted: Tank, area of 1500 m2 , 30 % loss

Formula: Area, m2 x DFT10 x % VS x Efficiency

CALCULATION