Graco EQ300C User Manual
Metering
Metering
Metering Valve
Valve
Valve Settings
Settings
Settings
There is no fixed formula for what works best in each application. The information below works best for the
majority of the time. From this initial setting, adjustments can be made up or down to get the fastest removal
rates without damage to the surface.
majority of the time. From this initial setting, adjustments can be made up or down to get the fastest removal
rates without damage to the surface.
Normal settings are: 110 psi (7.5 Bar, 0.75 MPa) initial pot setting, less than 1/2 turn open metering valve,
blasting pressure at 80 psi (5.5 Bar, 0.55 MPa). For applications requiring higher performance, use
high-performance abrasive (the heaviest mass @ 80 grit) such as Garnet, and the highest pressures the
compressor can support. The initial pot pressure should always be 30 psi (2.0 Bar, 0.2 MPa) above the
intended blast pressure.
blasting pressure at 80 psi (5.5 Bar, 0.55 MPa). For applications requiring higher performance, use
high-performance abrasive (the heaviest mass @ 80 grit) such as Garnet, and the highest pressures the
compressor can support. The initial pot pressure should always be 30 psi (2.0 Bar, 0.2 MPa) above the
intended blast pressure.
Gradually make adjustments to meet the specific requirements for each application. Higher blast pressures
will require turning the abrasive metering valve slightly more open (and vice versa). Make the adjustments
(see
will require turning the abrasive metering valve slightly more open (and vice versa). Make the adjustments
(see
) to achieve 7-10 cycles per minute to be the most efficient (cut at the fastest
rate while using the least amount of abrasive). Blasting pressures can range between 30 - 120 psi max
(2.0 Bar, 0.2 MPa – 8.2 Bar, 0.82 MPa).
(2.0 Bar, 0.2 MPa – 8.2 Bar, 0.82 MPa).
Unlike conventional sandblasting, higher pressures do not necessarily mean better cleaning. Nozzle distance
and the angle to the surface has an effect on performance, as does the blast pressure. Choice of abrasive
also has a great effect. High-performance abrasive produces the best performance and can save enough
time to make up the difference in cost.
and the angle to the surface has an effect on performance, as does the blast pressure. Choice of abrasive
also has a great effect. High-performance abrasive produces the best performance and can save enough
time to make up the difference in cost.
NOTE:
NOTE:
NOTE: Blasting with 150+ feet of blast hose requires the use of an electric blast control.
Grit
Grit
Grit Size
Size
Size
Blast
Blast
Blast Pressure
Pressure
Pressure
Abrasive
Abrasive
Abrasive Dose
Dose
Dose
Blast
Blast
Blast Angle
Angle
Angle
Notes
Notes
Notes
General
General
General
40/70
60-80 psi (4.1 Bar,
0.41 MPa- 5.5 Bar,
0.55 MPa)
0.41 MPa- 5.5 Bar,
0.55 MPa)
1/4 to 1/2 turns
35° - 65°
When the blast
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
Wood
Wood
Wood
80 (using a low
mass abrasive
like glass)
mass abrasive
like glass)
40-50 psi (2.7 Bar,
0.27 MPa- 3.4 Bar,
0.34 MPa)
0.27 MPa- 3.4 Bar,
0.34 MPa)
1/8 to 1/4 turns
15° - 30°
Do not wash, as it
may raise the wood
grain. Brush off
excess abrasive after
the wood dries.
may raise the wood
grain. Brush off
excess abrasive after
the wood dries.
Steel
Steel
Steel
80-100 (using
a high-mass
abrasive like
Garnet)
a high-mass
abrasive like
Garnet)
100-120 psi (6.8 Bar,
0.68 MPa- 8.2 Bar,
0.82 MPa)
0.68 MPa- 8.2 Bar,
0.82 MPa)
1/4 – 1/2 turns
65° - 85˚
When the blast
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
Fiberglass
Fiberglass
Fiberglass
40-70 low mass
45-65 psi (3.1 Bar,
0.31 MPa- 4.4 Bar,
0.44 MPa)
0.31 MPa- 4.4 Bar,
0.44 MPa)
1/8 to 1/4 turns
35° - 45˚
When the blast
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
pressure is
increased, the
abrasive dose turns
will also need to be
increased.
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