CALCULATIONS and FORMULAS GUIDE for
PAINTS and COATINGS
INDEX
Page
How to Specify Blasting …………………………………………………………………………….1
Abrasive / Profile Comparative Chart ………………………………………………………. 2
Reduction in Solids Content by Adding Thinner ……………………………………….. 3
Volume of Thinner Required to Thin % Shown ………………………………………… 4
Wet Film Thickness Requirements ………………………………………………………….. 5
Theoretical Coverage in Square Feet ……………………………………………………….. 6
Coating Coverage Calculations ………………………………………………………………… 7
Abrasive Consumption per Hour ……………………………………………………………… 8
Examples of Abrasive Cleaning Rates ………………………………………………………. 9
Examples of Cleaning Production Rates …………………………………………………… 9
Pressure Loss in Air Line ………………………………………………………………............. 10‐11
Commonly Used Formulas and Calculations ……………………………………………. 12
Estimating Square Footage in Various Shapes …………………………………………. 13‐14
1116 E. Scott Ave.
●
Wichita Falls, TX 76308
●
(940) 767‐9912
●
www.excaliburpaint.com
HOW TO SPECIFY BLASTING
Your coating supplier will always designate the degree of surface preparation required for his materials.
The three basic standards used to describe surface preparation are: Steel Structure Painting Council
(SSPC) "Surface Preparation Specifications", the National Association of Corrosion Engineers Standards
(N.A.C.E.) and the Swedish Pictoral Standards. Their basic definitions are:
SSPC
SWEDISH*
DESCRIPTION
N/A
Removal of oil, grease, dirt, soil and
contaminants by cleaning with solvent,
vapor, alkali, emulsion or steam.
St 2
Removal of loose rust, loose mill scale and
loose paint by hand chipping, scraping,
sanding and wire brushing.
N/A
St 3
Removal of loose rust, loose mill scale and
loose paint by power tool chipping,
descaling, sanding, wire brushing and
grinding.
SP 5, White Metal Blast
Cleaning
1
Sa 3
Removal of all visible rust, mill scale, paint
and foreign matter by blast cleaning.
SP 6, Commercial Blast
Cleaning
3
Sa 2
Blast cleaning until at least two thirds of
each square inch is free of all visible
residues.
SP 7, Brush‐Off Blast
Cleaning
4
Sa 1
Blast cleaning of all except tightly adhered
residues of mill scale, rust and coatings.
SP 1, Solvent Cleaning
SP 2, hand Tool Cleaning
SP 3, Power Tool
Cleaning
NACE
N/A
N/A
Complete removal of rust and mill scale by
acid pickling, duplex pickling or electrolytic
pickling.
SP 8, Pickling
SP 10, Near White Blast
Cleaning
2
Sa 2½
Blast cleaning until at least 95% of each
square inch is free of all visible rust, mill
scale, paint and foreign matter.
SP 11‐87T, Power Tool
Cleaning to Bare Metal
N/A
N/A
Removal of all visible rust, mill scale, paint
and foreign matter using power tools and
producing a minimum profile of 1 mil.
ABRASIVE / PROFILE COMPARATIVE CHART
The following chart should be used only for approximating the abrasive size required to
obtain a specified anchor pattern. The standard metal used to obtain these results was hot
rolled steel with tightly adhering mill scale. The resulting depth of anchor pattern will vary
with the method used for measuring depths as well as any one of numerous other
variables (type and hardness of steel, thickness of mill scale, degree of cleaning specified,
etc.) This information can be used for centrifugal wheel as well as pressure blasting.
Pressure blasting should be done using 90-100 psi nozzle pressure. The depth of anchor
pattern used in this chart is an average and not a minumum of maximum depth obtainable.
Consult local abrasive suppliers for specific technical data.
1 Mil Profile
1.5 Mil Profile
30/60 Mesh Silica Sand
G‐80 Steel Grit
S‐110 Steel Shot*
80 Mesh Garnet
100 Aluminum Oxide
Clemtex #4
Black Beauty 3060
16/35 Mesh Silica Sand
G‐50 Steel Grit
S‐170 Steel Shot*
36 Mesh Garnet
50 Grit Aluminum Oxide
Clemtex #3
Black Beauty 3060
2 Mil Profile
2.5 Mil Profile
16/35 Mesh Silica Sand
G‐40 Steel Grit
S‐230 Steel Shot*
36 Mesh Garnet
36 Grit Aluminum Oxide
Clemtex #3
Black Beauty 2040
8/35 Mesh Silica Sand
G‐40 Steel Grit
S‐280 Steel Shot*
16 Mesh Garnet
24 Grit Aluminum Oxide
Clemtex #2
Black Beauty 2040
3 Mil Profile
8/20 Mesh Silica Sand
G‐25 Steel Grit
S‐330 or 390 Steel Shot*
16 Mesh Garnet
16 Grit Aluminum Oxide
Clemtex #2
Black Beauty 1240
*Steel shot alone will not give a good angular pattern and should be used in combination with steel
grit for best results.
REDUCTION IN SOLIDS CONTENT BY ADDING THINNER
(THINNER ADDED)
Original
Solids
Content of
Material
Before
Adding
Thinner
%
2%
5%
7%
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
98
93
88
83
78
74
69
64
59
54
49
44
39
34
29
24
95
90
86
81
76
71
67
62
57
52
48
43
38
33
29
24
93
89
84
79
75
70
65
61
56
51
47
42
37
32
28
23
10% 12% 15% 17% 20% 25% 30% 35%
91
86
82
77
73
68
64
59
55
50
46
41
36
31
27
23
89
85
80
76
71
67
63
58
54
49
45
40
36
31
27
22
87
83
78
74
70
65
61
57
52
48
44
39
35
30
26
22
85
81
77
73
68
64
60
56
51
47
43
38
34
30
26
21
83
79
75
71
67
63
59
54
50
46
42
37
33
29
25
21
80
76
72
68
64
60
56
52
48
44
40
36
32
28
24
20
77
73
69
65
62
58
54
50
46
42
39
35
31
27
23
19
74
70
67
63
59
56
52
48
44
41
37
33
30
26
22
19
Solids
Content
After
Thinner
VOLUME OF THINNER REQUIRED
TO THIN PERCENTAGE SHOWN
1 Gallon Kit
%
2
5
7
10
12
15
17
20
25
30
35
Oz.
2.6
6.5
9.0
12.8
15.4
19.2
21.8
25.6
32.0
38.4
44.8
5 Gallon Kit
Liter
0.08
0.19
0.27
0.38
0.46
0.57
0.64
0.76
0.95
1.14
1.32
%
2
5
7
10
12
15
17
20
25
30
35
5 Liter Kit
%
2
5
7
10
12
15
17
20
25
30
35
Liter
0.10
0.25
0.35
0.50
0.60
0.75
0.85
1.00
1.25
1.50
1.75
Oz.
13.0
32.5
45.0
64.0
77.0
96.0
109.0
128.0
160.0
192.0
224.0
Liter
0.40
0.95
1.35
1.90
2.30
2.85
3.20
3.80
4.75
5.70
6.60
20 Liter Kit
Oz.
3.5
8.5
12.0
17.0
20.5
25.5
29.0
34.0
42.5
50.5
59.0
%
2
5
7
10
12
15
17
20
25
30
35
Liter
0.4
1.0
1.4
2.0
2.4
3.0
3.4
4.0
5.0
6.0
7.0
Oz.
14.0
34.0
48.0
68.0
82.0
102.0
116.0
136.0
170.0
202.0
236.0
WET FILM THICKNESS REQUIREMENTS
Required Dry Film Thickness (Mils)
Solids
Content of
Material
After
Thinning
%
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
2.0
2.1
2.2
2.4
2.5
2.7
2.9
3.1
3.3
3.6
4.0
4.4
5.0
5.7
6.7
8.0
3.0
3.2
3.3
3.5
3.8
4.0
4.3
4.6
5.0
5.5
6.0
6.7
7.5
8.6
10.0
12.0
4.0
4.2
4.4
4.7
5.0
5.3
5.7
6.2
6.7
7.3
8.0
8.9
10.0
11.4
13.3
16.0
5.0
5.3
5.6
5.9
6.3
6.7
7.1
7.7
8.3
9.1
10.0
11.1
12.5
14.3
16.7
6.0
6.3
6.7
7.1
7.5
8.0
8.6
9.2
10.0
10.9
12.0
13.3
15.0
17.1
7.0
7.4
7.8
8.2
8.8
9.3
10.0
10.8
11.7
12.7
14.0
15.6
17.5
8.0
8.4
8.9
9.4
10.0
10.7
11.4
12.3
13.3
14.6
16.0
17.8
9.0
9.5
10.0
10.6
11.3
12.0
12.9
13.9
15.0
16.4
18.0
10.0
10.5
11.1
11.8
12.5
13.3
14.3
15.4
16.7
18.2
11.0
11.6
12.2
12.9
13.7
14.6
15.7
16.9
18.3
12.0
12.6
13.3
14.1
15.0
16.0
17.1
18.5
13.0
13.7
14.4
15.3
16.3
17.3
18.6
14.0
14.7
15.6
16.5
17.5
18.7
20.0
15.0
15.8
16.7
17.7
18.8
20.0
21.4
16.0
16.8
17.8
18.8
20.0
21.3
22.9
17.0
17.9
18.9
20.9
21.3
22.7
24.3
Note: Dry film thicknesses are minimum. No allowance is made for evaporation of solvents during application.
Wet Film
Thickenss
Required
Example:
Matl. = 70%
Solids
DFT = 6 mils
Wet Film =
8.6 mils
THEORETICAL COVERAGE IN SQUARE FEET PER U.S. GALLON
Required Dry Film Thickness Per Coat (Mils)
Solids
Content by
Volume
%
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
1604
1524
1444
1363
1283
1203
1123
1043
962
882
802
772
642
561
481
401
802
762
722
682
642
602
561
521
481
441
401
361
321
281
241
201
535
511
481
455
428
401
374
348
321
294
267
241
214
187
160
134
401
381
361
341
321
301
281
261
241
221
201
181
160
140
120
100
321
305
289
273
257
241
225
209
193
176
160
144
128
112
96
80
267
254
241
227
214
201
187
174
160
147
134
120
107
94
80
67
229
218
206
195
183
172
160
149
138
126
115
103
92
80
69
57
201
191
181
170
160
150
140
130
120
110
100
90
80
70
60
50
178
169
160
152
143
134
125
116
107
98
89
80
71
62
54
45
160
152
144
136
128
120
112
104
96
88
80
72
64
56
48
40
146
139
131
124
117
109
102
95
88
80
73
66
58
51
44
37
135
127
120
114
107
100
94
87
80
74
67
60
54
47
40
33
123
117
111
105
98
92
86
80
74
68
62
55
49
43
37
31
115
109
104
98
92
86
80
75
69
63
58
52
46
40
35
29
107
102
96
91
86
80
75
70
64
59
54
48
43
37
32
27
100
95
90
85
80
75
70 Theoretical
Coverage Per
65
Gallon
60
55
50
45
40
35
30
25
COATING COVERAGE CALCULATIONS
Theoretical Coverage
(on smooth surface)
= Theoretical Coverage ‐
Practical Coverage
Consumption
=
ft² / U.S. gal =
% SBV/100 x 1604
dft (mils)
m² / 1 =
% SBV/100 x 1000
dft (micronsn)
Theoretical Coverage x % Loss
100
Area (ft² or m²)
Practical Coverage (gallons or liters)
Film Thickness
Wet to Dry:
wft x % SBV
100
Dry to Wet:
dft x 100
% SBV
% Solids by Volume and wet film thickness adjustments due to thinning
W
=
A
W
X
Y
Z
=
=
=
=
=
X
1+Y
A
=
adjusted WFT required for thinned material
adjusted % solids by volume due to thinning
original materials % solids by volume
% thinner added
required dry film thickness
Z
W
ABRASIVE CONSUMPTION PER HOUR
and
AIR CONSUMPTION IN CUBIC FEET PER MINUTE
Pressure at Nozzle
Orifice
Size
3/16"
(5mm)
1/4"
(6mm)
5/16"
(8mm)
3/8"
(10mm)
7/16"
(11mm)
1/2"
(13mm)
5/8"
(16mm)
3/4"
(19mm)
60 PSI
70 PSI
80 PSI
90 PSI
100 PSI
30
171
7
54
312
12
89
534
20
126
764
28
170
1032
38
224
1336
50
356
2140
80
504
3056
112
33
196
7.5
61
354
13.5
101
604
22.5
143
864
32
194
1176
43.5
252
1512
56
404
2422
90
572
3456
127
38
216
8.5
68
408
15
113
672
25.5
161
960
36
217
1312
48.5
280
1680
62.5
452
2690
100
644
3840
143
41
238
9.5
74
448
16.5
126
740
28
173
1052
38.5
240
1448
53.5
309
1856
69
504
2973
112
692
4208
154
45
264
10
81
494
18
137
812
30.5
196
1152
44
254
1584
56.5
338
2024
75
548
3250
122
784
4608
175
Air (CFM)
Sand (lb/hr)
H.P.*
Air
Sand
H.P.
Air
Sand
H.P.
Air
Sand
H.P.
Air
Sand
H.P.
Air
Sand
H.P.
Air
Sand
H.P.
Air
Sand
H.P.
*Electric motor horsepower required to product indicated C.F.M.
EXAMPLES OF ABRASIVE CLEANING RATES¹
Abrasive
Silica Sand
16 / 40 Mesh
Crushed Flint
12 / 30 Mesh
Staurolite
50 / 100 Mesh
Coal Slag
16 / 40 Mesh
Copper Slag
16 / 40 Mesh
*Garnet 36
Grit
*Aluminum
Oxide 36 Grit
*G‐40 Steel
Grit
Abrasive
Consumption
Production
Rate
Comments
2.6 lbs. / sq. ft.
275 ft² / hr.
1½ mil profile
dusty
3.6 lbs. / sq. ft.
161 ft² / hr.
3 mils
3.1 lbs. / sq. ft.
291 ft² / hr.
1½ mil profile
smooth surface
3.2 lbs. / sq. ft.
230 ft² / hr.
2½ mil profile
3.1 lbs. / sq. ft.
262 ft² / hr.
2 mil profile
*3.6 lbs. / sq. ft.
213 ft² / hr.
*3.1 lbs. / sq. ft.
275 ft² / hr.
*5.5 lbs. / sq. ft.
184 ft² / hr.
1½ mil profile
very little dust
1½ mil profile
very little dust
2½ mil profile
no dust
*These abrasives are normally reused
¹Newly fabricated steel using a 3/8" I.D. orifice nozzle and 100 psi to a SSPC‐SP 10
near white condition.
EXAMPLES OF CLEANING PRODUCTION RATES¹
1.
2.
3.
4.
5.
6.
7.
Method
Production Rate
SSPC‐SP 1
SSPC‐SP 2
SSPC‐SP 3
SSPC‐SP 5
SSPC‐SP 6
SSPC‐SP 7
SSPC‐SP 10
500 ft² / hour
250‐300 ft² / hour
100 ft² / hour
1000 ft² ¹
2500 ft² ¹
5200 ft² ¹
1500 ft² ¹
Abrasive Used
1 gal / hour
4 units / day
2 units / day
10,000 lbs.
8,000 lbs.
7,000 lbs.
12,500 lbs.
¹Per a 3 person crew day on lightly rusted steel, using 30 / 40 mesh medium hardness
abrasive, 3/8" orifice nozzle at 80 psi.
PRESSURE LOSS IN HOSE
Lubrication Only at Tool - No Line Lubricator
Hose Length
and
Inside Diameter
50 Feet
3/4"
50 Feet
1"
50 Feet
1¼"
50 Feet
1½"
cfm
Free
Air
60
80
100
120
140
160
180
200
220
120
150
180
210
240
270
300
330
360
390
420
450
200
250
300
350
400
450
500
550
600
650
700
750
800
300
400
500
600
700
800
900
1000
1100
1200
1300
Line Pressure ‐ psig
60
80
100
3.1
5.3
8.1
2.4
4.2
6.4
9.0
12.0
2.0
3.5
5.2
7.4
9.9
12.7
2.7
4.1
5.8
7.7
2.1
3.2
4.6
6.1
7.9
9.8
12.0
2.4
3.7
5.2
7.0
8.9
2.1
3.7
5.6
8.0
120
150
200
300
2.9
4.5
6.3
8.4
10.8
13.6
16.6
2.4
3.6
5.1
6.9
8.9
11.1
13.5
16.2
1.8
2.8
3.9
5.3
6.8
8.5
10.5
12.4
1.2
1.9
2.7
3.6
4.6
5.8
7.1
8.4
2.6
3.5
4.5
5.6
6.9
8.2
9.7
11.3
13.0
14.8
2.0
2.7
3.4
4.3
5.3
6.3
7.4
8.7
10.0
11.4
1.3
1.8
2.3
2.9
3.6
4.3
5.0
5.9
6.8
7.7
2.3
3.1
4.0
5.0
6.2
7.4
8.7
10.2
11.7
13.3
15.0
1.8
2.4
3.1
3.9
4.7
5.7
5.7
7.8
9.0
10.2
11.5
1.2
1.6
2.1
2.6
3.2
3.9
4.6
5.3
6.1
6.9
7.8
2.5
3.6
4.9
6.3
7.8
9.5
11.4
13.6
15.8
1.9
2.8
3.7
4.8
6.0
7.3
8.8
10.4
12.1
1.3
1.9
2.5
3.2
4.1
4.9
6.0
7.1
8.3
2.7
3.8
4.0
6.5
8.1
9.9
11.8
13.9
2.3
3.2
4.3
5.5
6.9
8.4
10.0
11.9
13.8
15.9
2.9
4.1
5.5
7.0
8.8
10.8
2.4
3.4
4.5
5.8
7.3
8.9
10.7
12.6
14.6
2.0
2.9
3.8
4.9
6.2
7.6
9.1
10.7
12.4
14.3
2.9
4.4
6.3
8.5
10.9
2.4
3.7
5.2
7.0
9.0
11.2
13.6
2.0
3.1
4.4
5.9
7.7
9.5
11.6
14.0
PRESSURE LOSS IN HOSE - cont.
Lubrication Only at Tool - No Line Lubricator
Line Pressure ‐ psig
Hose Length
and
cfm
Free
Inside Diameter
Air
60
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
1000
1500
2000
2500
3000
3500
4000
4500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
5000
6000
7000
8000
9000
10000
11000
12000
13000
14000
15000
16000
17000
1.9
3.2
5.0
7.0
9.3
50 Feet
2"
50 Feet
2½"
50 Feet
3"
25 Feet
4"
1.7
3.7
6.5
10.0
2.5
3.9
5.5
7.5
9.8
1.9
2.7
3.6
4.7
5.9
7.2
8.7
80
100
2.5
3.9
5.5
7.4
9.6
12.1
2.1
3.2
4.5
6.1
7.9
9.9
12.2
14.6
2.9
5.1
7.9
11.2
2.4
4.2
6.5
9.3
12.4
2.0
3.6
5.5
7.9
10.6
13.7
2.5
3.6
4.9
6.3
7.9
9.6
11.5
13.6
2.1
3.1
4.1
5.3
6.7
8.2
9.8
11.5
13.5
15.6
2.0
3.0
4.4
5.9
7.6
9.6
11.7
2.1
2.8
3.7
4.6
5.7
6.8
8.1
9.4
1.7
2.3
3.0
3.8
4.7
5.6
6.7
7.8
9.0
120
150
200
300
2.7
3.8
5.2
6.7
8.4
10.4
12.5
14.7
2.2
3.1
4.2
5.5
6.9
8.5
10.2
12.0
14.1
16.2
1.7
2.4
3.2
4.2
5.3
6.5
7.8
9.2
10.8
12.4
1.1
1.6
2.2
2.8
3.6
4.4
5.3
6.3
7.3
8.5
2.9
4.5
6.4
8.7
11.2
14.0
2.2
3.4
4.9
6.6
8.6
10.7
1.5
2.3
3.3
4.5
5.8
7.3
2.5
3.4
4.4
5.5
6.7
8.0
9.4
11.0
12.7
14.5
1.9
2.6
3.3
4.2
5.1
6.1
7.2
8.4
9.8
11.1
1.3
1.7
2.3
2.8
3.5
4.2
4.9
5.7
6.6
7.6
2.1
2.6
3.2
3.9
4.6
5.4
6.2
7.1
8.0
9.1
1.2
1.6
2.0
2.5
3.0
3.5
4.1
4.8
5.4
6.2
6.9
2.0
2.6
3.2
4.0
4.8
5.7
6.6
7.6
8.7
9.8
COMMONLY USED FORMULAS for CALCULATING SURFACE AREA
Squares and Rectangles
a The areas of a square and of a
rectangle are obtained by multiplying the
length of one side
by the length of the other, i.e.
square = a x a
a
rectangle = a x b
a
b
a
a
a
Spheres
The surface area of a sphere is
3.1416 multiplied by the square of
the diameter i.e.
3.1416 x d x d
d
L
d
L
R
d
Cubes
A cube has 6 sides that are all identical
squares. To calculate the total surface
area, multiply 6 by the
square of the length (a) of one of the
sides i.e.
6 x a x a
Pipes
The surface area of a pipe is 3.1416
multiplied by the diameter (d) and by the
length (L) i.e.
3.1415 x d x L
Cylindrical Tanks
The surface area consists of the
cylindric shell plus the top and
bottom area i.e.
3.1416 x d x L + 2 x (3.1416 x R x R)
ESTIMATING SQUARE FOOTAGE IN VARIOUS SHAPES
Cylinder
a. Determine area of both ends of cylinder
(circles) by multiplying 3.1416 times the
radius (in feet) squared.
b. Determine area of side of cylinder by
multiplying circumference (in feet) times
height (in feet).
c. Add square feet of both ends to square
feet of side for total square feet of
cylinder.
Cone
a. Determine area of base by multiplying
3.1416 times the radius (in feet)
squared.
b. Determine the area of the side of the
cone by multiplying circumference of
base (in feet) times one-half of the slant
height (in feet).
c. Add the square foot area of the base to
the square foot area of the cone side for
total square foot area.
Triangle
Multiply the base measurement (in feet)
times one-half the altitude (in feet).
Circle
To determine the square footage of the area
of a circle, multiply 3.1416 times the radius (in
feet) squared.
Circumference
To determine the circumference of a circle,
multiply 3.1416 times the diameter (twice the
radius).
Square or Rectangle
Multiply the base measure (in feet)
times the height (in feet).
Estimating Square Footage from Tonnage
Many times structures will have unusual shapes or be too difficult to
accurately measure. In such instances, if the tonnage and
thickness of the steel can be determined, fairly accurate estimates
of area can be determined from the table below.
Thickness
of Steel
(inches)
1/8
3/16
1/4
5/16
3/8
1/2
5/8
3/4
7/8
1
1-1/2
2
Square
Foot Area
Per Ton
800
533
400
320
267
200
160
133
114
100
67
50