Marco BLASTMASTER 121P User manual

Before using this equipment, read, understand and follow all instructions
in the Operator’s Manuals provided with this equipment. If the user and/
or assistants cannot read or understand the warnings and instructions,
the employer of the user and/or assistants must provide adequate and necessary training to
ensure proper operation and compliance with all safety procedures pertaining to this equipment. If
Operator’s Manuals have been lost, please visit www.marco.us, or contact Marco at 563.324.2519
for replacements. Failure to comply with the above warning could result in death or serious injury.
OPERATOR’S MANUAL
BLASTMASTER®121P
REMOTE CONTROL SYSTEM

Blastmaster®121P Remote Control System
1
Company Profile
Since 1944, Marco has developed a strong tradition of providing innovative and reliable products and services to the
surface preparation and protective coatings industries. We are the world’s premier provider of Abrasives, Blasting
Equipment, Coating and Painting Equipment, Engineered Systems, Rental Equipment, Safety Equipment,
Service, and Repair.
Through innovative designs and a total commitment to quality, Marco manufactures products that increase production
rates, create a safer workplace, and reduce maintenance costs. Marco’s industry experience, manufacturing
capabilities, legendary customer service, product availability, logistics services, and technology leadership is your
assurance that we deliver high quality products and services, providing the best value to you, our customer.
The Marco Difference
• Industry Experience – With Marco on your team, you have access to expertise which can only come from decades
of industry leadership. We have organized our engineering department, production specialists, customer operations,
and safety support into a “Center of Competence.” As a Marco customer, you have access to hundreds of years of
cumulative experience related to your operations.
• Manufacturing Excellence – Marco is a U.S. based, ISO 9001:2008 certified manufacturer of equipment for the
Surface Preparation and Protective Coatings industries. Marco’s engineers benchmark the industry to ensure that
we design and manufacture superior products that set the “Gold Standard” for performance, safety, and quality.
• Legendary Customer Service – Marco’s legendary customer service team is staffed by friendly, highly-trained
individuals who are focused on providing the highest level of product support, order accuracy, and customer
satisfaction.
• Product Availability – We stock over 10,000 SKU’s and have over 45 shipping locations to serve North American
and International markets for all major brands of blasting and painting equipment. As the largest provider of surface
preparation and protective coatings equipment in the world, our inventory levels and product availability are
unmatched.
•
Logistics Services – Marco’s in-house logistics team is dedicated to moving your shipment anywhere in the world.
We move over 14,000 truckloads every year, allowing you to save on freight costs by leveraging our buying power.
Lower your process costs with a single invoice, which includes product and freight.
• Technology Leadership – Our website provides: Operator’s Manuals, Part Numbers and Schematics Guides,
MSDS information, and Features, Advantages, and Benefits Guides, providing access to information 24/7. Our
Extranet application allows you to receive quotes and place orders online. Our Intranet maintains a complete record
of your purchase history to assist with ongoing support of your existing equipment and future purchasing decisions.
Vision Statement
Marco is the world’s premier provider of Abrasives, Blasting Equipment, Coating and Painting Equipment,
Engineered Systems, Rental Equipment, Safety Equipment, Service, and Repair.
Mission Statement
Marco provides strong leadership and innovation to the surface preparation and protective coatings industries We dedicate
our efforts to the continuous improvement of our products, services, processes, people, and most importantly, the quality of
our customer’s experience.
Quality Policy
Marco is committed to providing superior quality in the design, manufacturing, distribution, rental, service, and repair of our
products. Our ISO 9001:2008 certification extends throughout all operations in all locations. Continuous improvement of our
processes and supply chain Integration comprise the core of our business strategy for delivering exceptional quality and
value in all Marco products and services.
Management Philosophy
We are a company dedicated to the success of every customer and associate. We discuss, debate, challenge, measure,
and test our ideas. We will be boundless and limitless in our passion to improve. Through sound leadership and dedicated
associates, we will ensure a long term, profitable future for Marco, our associates, customers, and suppliers.

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Company Prole . . . . . . . . . . . . . . . . . . . . . . . . . 1
Denition of Terms . . . . . . . . . . . . . . . . . . . . . . 2
Hazard Identications . . . . . . . . . . . . . . . . . . . 3
Air & Abrasive Consumption Chart . . . . . . . 6
Daily Pre-Operation Checklist . . . . . . . . . . . . 8
Operating Instructions . . . . . . . . . . . . . . . . . . . 9
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Operational Requirements . . . . . . . . . . . . . . . . . 9
Operating Instructions . . . . . . . . . . . . . . . . . . . . 9
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Disassemble and Assemble 1-1/2" Inlet Valve 13
Disassemble and Assemble 1” Diaphragm
Outlet Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Disassemble and Assemble Abrasive Trap . . . 17
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . 19
TABLE OF CONTENTS
DEFINITION OF TERMS
This is an example of a warning. This indicates a
potentially hazardous situation which, if not avoided,
could result in death or serious injury.
This is an example of a notice. This indicates policy
or practice directly related to safety of personnel or
protection of property.
This is an example of danger. This indicates an
imminently hazardous situation which, if not avoided, will
result in death or serious injury.
This is an example of a caution. This indicates a
potentially hazardous situation which, if not avoided,
may result in minor or moderate injury. It can also be
used to alert against unsafe practices.
Assembly Part Numbers & Schematics . . 21
Blastmaster®121P Remote Control System. . . 21
1-1/2” Inlet Valve. . . . . . . . . . . . . . . . . . . . . . . . 23
1” Diaphragm Outlet Valve . . . . . . . . . . . . . . . 24
Abrasive Trap . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . 26
Disclaimer of Warranty . . . . . . . . . . . . . . . . . . . 26
Exclusive Remedy for Warranty Claims . . . . . . 26
Limitation of Remedies . . . . . . . . . . . . . . . . . . . 26

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Failure to comply with ANY WARNING listed below could result in death or serious injury.
OSHA sets exposure limits to protect workers from exposure to respirable crystalline silica, 29 CFR 1910.1053.
Airborne dust could increase the exposure levels beyond permissible limits. Breathing dust containing silica
could cause silicosis, a fatal lung disease. Breathing dust during abrasive blasting operations, post-blast cleaning
operations, and/or servicing equipment within the abrasive blasting area may expose an individual to conditions
that could cause asbestosis, lead poisoning and/or other serious or fatal diseases. Harmful dust containing toxic
material from abrasives or surfaces being abrasive blasted can remain suspended in the air for long periods of
time after abrasive blasting has ceased. A NIOSH-approved, well-maintained, respirator designed for the specific
operation being performed must be used by anyone abrasive blasting, handling or using the abrasive, and
anyone in the area of the dust.
Contact NIOSH and OSHA offices to determine the proper respirator for your specific application. The air supplied
to the respirator must be at least Grade D quality as described in Compressed Gas Association Commodity
Specification G-7.1 and as specified by OSHA Regulation 1910.134. Ensure air filter and respirator system hoses
are not connected to non-air sources or in-plant lines that may contain nitrogen, oxygen, acetylene or other
non-breathable gases. Before removing respirator, use an air monitoring instrument to determine if the
atmosphere is safe to breathe.
You must comply with all OSHA, local, City, State, Province, Country and jurisdiction regulations, ordinances and
standards, related to your particular work area and environment. Keep unprotected individuals out of the work
area.
Abrasive blasting operators must receive thorough training on the use of abrasive resistant attire which includes:
supplied-air respirator, abrasive blasting suit, safety shoes, gloves, ear protection and eye protection. Protect the
operator and bystanders by complying with NIOSH and OSHA Safety Standards.
Inspect all equipment for wear or damage before and after each use. Failure to use Original Equipment
Manufacturer repair parts and failure to immediately replace worn or damaged components could void warranties
and cause malfunctions.
OSHA requires abrasive blasting nozzles be equipped with an operating valve, which shall be designed to be
held open only by continuous hand pressure and shall close immediately upon release of hand pressure (i.e., a
“deadman” control). The valve shall not be modified in any manner that would allow it to remain open without the
application of continuous hand pressure by the operator. Failure to comply with the above warning could result in
release of high speed abrasive and compressed air resulting in death or serious injury. OSHA 29CFR 1910.244(b)
Point the abrasive blasting nozzle only at the surface being abrasive blasted. Never point the abrasive blasting
nozzle or abrasive stream at yourself or others.
Unless otherwise specified, maximum working pressure of abrasive blasting pots and related components must
not exceed 150 psi. Exceeding maximum working pressure of 150 psi could cause the abrasive blasting pot and
components to burst. Failure to comply with the above warning could result in death or serious injury.
Never weld, grind or drill on the abrasive blasting pot (or any pressure vessel). Doing so will void ASME
certification and manufacturer’s warranty. Welding, grinding or drilling on the abrasive blasting pot (or any pressure
vessel) could weaken the vessel causing it to burst. Failure to comply with the above warning could result in death
or serious injury. (ASME Pressure Vessel Code, Section VIII, Division 1)
This equipment is not intended for use in any area that might be considered a hazardous location, as described
in the National Electric Code NFPA 70, Article 500. Use of this equipment in a hazardous location could cause an
explosion or electrocution.
Never attempt to move an abrasive blasting pot containing abrasive. Never attempt to manually move abrasive
blasting pots greater than 6.5 cubic foot capacity. Always use at least two capable people to manually move an
abrasive blasting pot on flat, smooth surfaces. A mechanical lifting device must be used if an abrasive blasting pot
is moved in any other manner.
HAZARD IDENTIFICATIONS

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HAZARD IDENTIFICATIONS
Failure to comply with ANY WARNING listed below could result in death or serious injury.
This product is not for use in wet environments. Always use a Ground Fault Interrupter Circuit (GFIC) for
all electrical power source connections. Use of this product in wet environments could create a shock or
electrocution hazard.
Frozen moisture could cause restrictions and obstructions in pneumatic control lines. Any restriction or
obstruction in the pneumatic control lines could prevent the proper activation and deactivation of the remote
control system, resulting in the release of high speed abrasive and compressed air. In conditions where moisture
may freeze in the control lines an antifreeze injection system approved for this application can be installed.
Do not cut, obstruct, restrict or pinch pneumatic control lines. Doing so could prevent the proper activation and
deactivation of the remote control system, resulting in the release of high speed abrasive and compressed air.
Use of Marco remote control switches with other manufacturer’s remote control systems could cause unintended
activation of remote control systems resulting in the release of high speed abrasive and compressed air. Only
Marco remote control switches should be used with Marco remote control systems.
Always be certain to have secure footing when abrasive blasting. There is a recoil hazard when abrasive blasting
starts that may cause user to fall and misdirect the abrasive stream at operator or bystander.
Never use an abrasive blasting pot or attachments as a climbing device. The person could slip and fall. The
abrasive blasting pot could become unstable and tip over.
For equipment manufactured by entities other than Marco, you must consult the Original Equipment Manufacturer
operator’s manuals, information, training, instructions and warnings, for the proper and intended use of all
equipment.
Flammable fumes, such as solvent and paint fumes in the work area can present an ignition or explosion hazard
if allowed to collect in adequate concentrations. To reduce conditions that could result in a fire or an explosion,
provide adequate ventilation, eliminate all ignition or spark sources, keep the work area free of debris, store
solvents and solvent contaminated rags in approved containers, follow proper grounding procedures, do not
plug/unplug power cord or turn on/off power switches when flammable fumes are present, keep a working fire
extinguisher or provide another fire suppression system in the work area. Cease all operations and correct
condition if a spark or ignition source is identified during operation.
Always depressurize the entire system, disconnect all power sources and lockout/tagout all components before
any maintenance or troubleshooting is attempted. Failure to comply with the above warning could cause electrical
shock and inadvertent activation of equipment resulting in death or serious injury.
Moving parts can present an area where crushing, pinching, entanglement or amputation may occur. Do not
place body parts or foreign objects in any area where there are moving parts.
Surfaces of heated supply tanks, drums and/or lines as well as the adjoining plumbing may become hot during
normal use. Do not touch these heated surfaces without proper protection. Deactivate and allow sufficient time for
all surfaces to cool before attempting any maintenance.
High-pressure fluid from gun, hose leaks, or ruptured components can pierce skin and can cause a serious injury
that may result in amputation. Do not point gun or spray tip at anyone or at any part of the body. Keep clear
of any leaks or ruptures. Depressurize the entire system before attempting cleaning, inspecting, or servicing
equipment.
Exposure to toxic fluids or fumes may occur during the normal operation of this system. Before attempting to
fill, use, or service this system, read SDS’s to know the specific hazards of the fluids you are using. Always use
proper Personal Protective Equipment when attempting to fill, use, or service this system.
The use of this product for any purpose other than originally intended or altered from its original design is
prohibited.
Never hang objects from the abrasive blasting pot handle. Doing so may cause the abrasive blasting pot to
become unstable and tip over.

Blastmaster®121P Remote Control System
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HAZARD IDENTIFICATIONS
Failure to comply with ANY CAUTION listed below may result in minor or moderate injury.
Static electricity can be generated by abrasive moving through the abrasive blasting hose causing a shock
hazard. Prior to use, ground the abrasive blasting pot and abrasive blasting nozzle to dissipate static electricity.
High decibel noise levels are generated during the abrasive blasting process which may cause loss of hearing.
Ensure appropriate Personal Protective Equipment and hearing protection is in use.
Failure to comply with ANY NOTICE listed below could pose a hazard to personnel or property.
See Air & Abrasive Consumption Chart for estimated abrasive consumption rates and required air flow (cubic feet
per minute). Your system must meet these minimum requirements to ensure proper function and performance.
Always use abrasive that is dry and properly screened. This will reduce the potential for obstructions to enter the
remote control system, abrasive metering valve and abrasive blasting nozzle.
Moisture build-up occurs when air is compressed. Any moisture within the abrasive blasting system will cause
abrasive to clump, clogging metering valves, hoses and nozzles. Install an appropriately sized moisture separator
at the inlet of the abrasive blasting system. Leave the moisture separator petcock slightly open to allow for
constant release of water. If insufficient volume of air exists and petcock is unable to be left open (at all times)
petcock should be opened frequently to release water.
To reduce abrasive intrusion in the air supply hose, depressurize the abrasive blasting pot before shutting off air
supply from compressor.
Inspect abrasive blasting nozzle before placing into service. Damage to abrasive blasting nozzle liner or
jacket may occur during shipping. If you receive a damaged abrasive blasting nozzle, contact your distributor
immediately for replacement. Abrasive blasting nozzles placed into service may not be returned. Abrasive blasting
nozzle liners are made of fragile materials and can be damaged by rough handling and striking against hard
surfaces. Never use a damaged abrasive blasting nozzle.
Abrasive blasting at optimal pressure for the abrasive used is critical to productivity. Example: For an abrasive
with an optimal abrasive blasting pressure of 100 psi at the abrasive blasting nozzle, one pound per square inch
of pressure loss will reduce abrasive blasting efficiency by 1.5%. A 10 psi reduction in air pressure will cause a
15% loss of efficiency. Use a Needle Pressure Gauge to identify pressure drops in your system. Consult with your
abrasive supplier for the requirements of your abrasive.
Replace abrasive blasting nozzle if liner or jacket is cracked or damaged. Replace abrasive blasting nozzle if
original orifice size has worn 1/16” or more. Determine abrasive blasting nozzle wear by inserting a drill bit 1/16”
larger than original size of abrasive blasting nozzle orifice. If the drill bit passes through abrasive blasting nozzle,
replacement is needed.

Blastmaster®121P Remote Control System 6
Failure to comply with ANY NOTICE listed below could pose a hazard to personnel or property.
See Air & Abrasive Consumption Chart for estimated abrasive consumption rates and required air flow
(cubic feet per minute). Your system must meet these minimum requirements to ensure proper function and
performance.
When it comes to air & abrasive mixtures, more is not necessarily better. Optimum abrasive blasting efficiency
takes place when a lean air & abrasive mixture is used. To correctly set the abrasive metering valve, begin
with the valve fully closed and slowly increase the amount of abrasive entering the airstream. As you increase
the abrasive flow, watch for a “blue flame” at the exit of the abrasive blasting nozzle. Faster cutting, reduced
abrasive consumption and lower clean up costs, are benefits of the “blue flame”.
Abrasive blasting at optimal pressure for the abrasive used is critical to productivity. Example: For an abrasive
with an optimal abrasive blasting pressure of 100 psi at the abrasive blasting nozzle, one pound per square inch
of pressure loss will reduce abrasive blasting efficiency by 1.5%. A 10 psi reduction in air pressure will cause a
15% loss of efficiency. Use a Needle Pressure Gauge to identify pressure drops in your system. Consult with
your abrasive supplier for the requirements of your abrasive.
*Abrasive consumption is based on abrasive with a bulk density of 100 lbs per Cubic Foot
Air & Abrasive Consumption Chart*
Nozzle
Orifice
Pressure at the Nozzle (PSI) Air (in cfm), Abrasive
& Compressor
Requirements
50 60 70 80 90 100 125 140
No. 2
(1/8ˮ)
11
67
2.5
13
77
3
15
88
3.5
17
101
4
18
112
4.5
20
123
5
25
152
5.5
28
170
6.2
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
No. 3
(3/16ˮ)
26
150
6
30
171
7
33
196
8
38
216
9
41
238
10
45
264
10
55
319
12
62
357
13
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
No. 4
(1/4ˮ)
47
268
11
54
312
12
61
354
14
68
408
16
74
448
17
81
494
18
98
608
22
110
681
25
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
No. 5
(5/16ˮ)
77
468
18
89
534
20
101
604
23
113
672
26
126
740
28
137
812
31
168
982
37
188
1100
41
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
No. 6
(3/8ˮ)
108
668
24
126
764
28
143
864
32
161
960
36
173
1052
39
196
1152
44
237
1393
52
265
1560
58
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
No. 7
(7/16ˮ)
147
896
33
170
1032
38
194
1176
44
217
1312
49
240
1448
54
254
1584
57
314
1931
69
352
2163
77
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
No. 8
(1/2ˮ)
195
1160
44
224
1336
50
252
1512
56
280
1680
63
309
1856
69
338
2024
75
409
2459
90
458
2754
101
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
No. 10
(5/8ˮ)
308
1875
68.5
356
2140
79.5
404
2422
90
452
2690
100.5
504
2973
112
548
3250
122
663
3932
146
742
4405
165
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
No. 12
(3/4ˮ)
432
2672
96
504
3056
112
572
3456
127
644
3840
143
692
4208
154
784
4608
174.5
948
5570
209
1062
6238
236
Air (cfm)
Abrasive (lbs/hr)
Compressor Horsepower
Inspect abrasive
blasting nozzle before
placing into service.
Damage to abrasive
blasting nozzle liner
or jacket may occur
during shipping. If you
receive a damaged
abrasive blasting nozzle,
contact your distributor
immediately for
replacement. Abrasive
blasting nozzles placed
into service may not
be returned. Abrasive
blasting nozzle liners
are made of fragile
materials and can be
damaged by rough
handling and striking
against hard surfaces.
Never use a damaged
abrasive blasting nozzle.
Replace abrasive
blasting nozzle if liner
or jacket is cracked
or damaged. Replace
abrasive blasting nozzle
if original orifice size
has worn 1/16” or more.
Determine abrasive
blasting nozzle wear by
inserting a drill bit 1/16”
larger than original size
of abrasive blasting
nozzle orifice. If the
drill bit passes through
abrasive blasting nozzle,
replacement is needed.
“Blue Flame”
AIR & ABRASIVE CONSUMPTION CHART

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“THE BIG PICTURE”
3
5
7
4
4
3
21
8
9
17
14
1615
13
19
18
10
20
23
21
424
27
26
25
22
28
5
3
6
11
12

Blastmaster®121P Remote Control System 8
Daily Pre-operation Checklist
1. Abrasive
2. Air Compressor
3. Air Hose Couplings & Gaskets
4. Air Hose
5. Safety Cable
6. Ambient Air Pump*
7. Breathing Air Filter
8. CO Monitor
9. Breathing Line
10. Climate Control Device
11. Abrasive Blasting Suit
12. Gloves
13. Abrasive Blasting Nozzle
14. Lighting System*
15. Abrasive Blasting Nozzle Holder
16. Remote Control Switch
17. Supplied-Air Respirator
18. Control Line
19. Abrasive Blasting Hose
20. Abrasive Blasting Hose
Couplings & Gaskets
21. Abrasive Metering Valve
22. Remote Control System
23. Moisture Separator
24. Abrasive Blasting Pot Exhaust
Muffler
25. Abrasive Blasting Pot
26. Abrasive Blasting Pot Screen
27. Abrasive Blasting Pot Lid
28. Aftercooler*
* Optional or alternative device.
Ask your Marco Representative
for more details.
Abrasive – Select the correct Abrasive (1) for the application. Review the MSDS
(Material Safety Data Sheet) to ensure the correct PPE (Personal Protective
Equipment) and Environmental Controls have been selected and are in place.
Air Compressor – Select an Air Compressor (2) of adequate size to support all
equipment requirements. Refer to “Air & Abrasive Consumption Chart” for
Abrasive Blasting Nozzle (13) air consumption requirements. Before connecting
Air Hose (4), sample the air being produced by the air compressor (2) to ensure
it is free of petroleum contaminants.
Air Hose, and Air Hose Couplings & Gaskets – Select Air Hoses (4) of
sufficient size to support all subsequent volumetric requirements and with a
sufficient PSI (pound per square inch) rating. Inspect all Air Hoses (4), and Air
Hose Couplings & Gaskets (3) for damage or wear. Repair or replace damaged
or worn components.
Abrasive Blasting Hose, Abrasive Blasting Hose Couplings & Gaskets, and
Abrasive Blasting Nozzle Holder – Select an Abrasive Blasting Hose (19) that
has an inner diameter 3 to 4 times larger than your Abrasive Blasting Nozzle
(13). Inspect Abrasive Blasting Hose (19), Abrasive Blasting Hose Couplings
& Gaskets (20), and Abrasive Blasting Nozzle Holder (15) for damage or wear.
Repair or replace damaged or worn components.
Safety Cables – Install a Safety Cable (5) at each Abrasive Blasting Hose (19),
and Air Hose (4) connection points.
Aftercooler and Moisture Separator – Ensure Aftercooler (28) is positioned
on stable ground. Keep petcock drain of Moisture Separator (23) slightly open
during use. Drain both devices after each use.
Supplied-Air Respirator, Breathing Line, Breathing Air Filter, Climate
Control Device, CO Monitor, Ambient Air Pump – You MUST consult the
Operator’s Manual supplied with your Respiratory Equipment (6, 7, 8, 9,
10, 17) for ALL applicable instructions and warnings. Inspect all Respiratory
Equipment components for damage or wear. Repair or replace damaged or worn
components.
Abrasive Blasting Suit and Gloves – Select an abrasive-resistant Abrasive
Blasting Suit (11) that is slightly oversized to allow ease of movement and allows
air to flow around your body. Select abrasive-resistant Gloves (12) with a tight fit
and a long cuff that overlaps the sleeve of the Abrasive Blasting Suit (11).
Abrasive Metering Valve and Abrasive Blasting Pot – Confirm Abrasive
Blasting Pot (25) is positioned on stable ground. Inspect Abrasive Blasting Pot
(25) and Abrasive Metering Valve (21) for damage or wear. Repair or replace
damaged or worn components.
Abrasive Blasting Pot Screen and Abrasive Blasting Pot Lid – Always use
an Abrasive Blasting Pot Screen (26) when filling Abrasive Blasting Pot (25)
with Abrasive (1) to prevent debris from entering the Abrasive Blasting Pot (25).
Remove Abrasive Blasting Pot Lid (27) before operating the Abrasive Blasting
Pot (25). Install Abrasive Blasting Pot Lid (27) after use to protect the Abrasive
Blasting Pot’s (25) interior.
Remote Control System, Remote Control Switch, Control Line, – Inspect
Remote Control System (22) and Control Line (18) for damage or wear. Repair
or replace damaged or worn components. Ensure Control Line (18) fittings
connected to the Remote Control System (22) are tight and free of leaks. Ensure
Remote Control Switch (16) is functioning properly. Consult Remote Control
Switch Operator's Manual for applicable instructions.
Abrasive Blasting Pot Exhaust Muffler – Inspect Abrasive Blasting Pot
Exhaust Muffler (24) at start and end of daily use. Replace element of Abrasive
Blasting Pot Exhaust Muffler (24) per Operator's Manual instructions.
Lighting System – Ensure the Lighting System (14) is connected to a proper
power supply before use.
DAILY PRE-OPERATION CHECKLIST

Blastmaster®121P Remote Control System
9
Description
Remote control systems give an operator the ability to remotely activate and deactivate the
flow of air and abrasive at the nozzle. Pressure-release remote control systems pressurize
and depressurize the blast pot each time the operator activates and deactivates the remote
control switch, allowing the blast pot to be filled between activation cycles. This increases
productivity and eliminates the need for a pot tender. The Blastmaster®121P Remote
Control System is a pressure-release remote control system that uses a pneumatic signal
from the remote control switch to remotely activate and deactivate a blast pot. Typical
applications include blast rooms, blast yards, bridges, oil refineries, pipelines, railcar shops,
shipyards, and storage tanks.
Operational Requirements
The following is required for proper installation of a Blastmaster®121P Remote
Control System:
• A blast pot with an air inlet and air exhaust outlet of 1" I.D. or greater.
The following may cause safety hazards or reduced performance:
• Improper installation and/or maintenance of components
• Improper air supply pressure (operating pressure: 50–150 PSI)
• Improper electric power supply
Operating Instructions
Before using:
• Ensure blast pot is depressurized. See blast pot Operator’s Manual for instructions.
• Inspect all remote control lines ensuring they are free of obstructions or damage. Remove
obstructions or replace control lines before use.
• Inspect components of Blastmaster®121P Remote Control System for damage and air
leaks. Repair or replace damaged components before use.
• Ensure Petcock (4) on Inlet Valve (9) is in the OPEN position.
• Test Pneumatic Remote Control Switch (8) for proper functioning. (See pneumatic remote
control switch Operator’s Manual for instructions).
• Connect air supply hose from compressor to Inlet Port (5).
During use:
• To begin abrasive blasting, activate the Pneumatic Remote Control Switch (8), this will
complete an air circuit to the Inlet Valve (9) and Outlet Valve (2) to begin pressurizing the
blast pot.
• Monitor all components of the Blastmaster®121P Remote Control System for proper
functioning.
• Inspect and clean Abrasive Trap (1) at least twice daily to ensure correct functioning.
Repair or replace damaged components.
• To cease abrasive blasting, deactivate the Pneumatic Remote Control Switch (8), this will
interrupt the air circuit, allowing the blast pot to depressurize.
After use:
• Inspect Blastmaster®121P Remote Control System components for damage. Repair or
replace damaged components.
OPERATING INSTRUCTIONS
Always depressurize
the entire system,
disconnect all power
sources and lockout/
tagout all components
before any maintenance
or troubleshooting is
attempted. Failure to
comply with the above
warning could cause
electrical shock and
inadvertent activation of
equipment resulting in
death or serious injury.
W-562
OSHA requires blast
cleaning nozzles be
equipped with an
operating valve, which
shall be designed to
be held open only
by continuous hand
pressure and shall
close immediately upon
release of hand pressure
(i.e., a “deadman”
control). The valve
shall not be modified in
any manner that would
allow it to remain open
without the application
of continuous hand
pressure by the
operator. Failure
to comply with the
above warning could
result in release of
high speed abrasive
and compressed air
resulting in death or
serious injury. OSHA
29CFR 1910.244(b)
W-506
For equipment
manufactured by entities
other than Marco,
you must consult the
Original Equipment
Manufacturer operator’s
manuals, information,
training, instructions
and warnings, for the
proper and intended
use of all equipment.
Failure to comply with
the above warning
could result in death or
serious injury.
W-511

Blastmaster®121P Remote Control System 10
OPERATING INSTRUCTIONS
Inspect all equipment for
wear or damage before
and after each use.
Failure to use Original
Equipment Manufacturer
repair parts and failure
to immediately replace
worn or damaged
components could void
warranties and cause
malfunctions. Failure to
comply with the above
warning could result in
death or serious injury.
W-505
This product is
not for use in wet
environments. Always
use a Ground Fault
Interrupter Circuit (GFIC)
for all electrical power
source connections.
Use of this product
in wet environments
could create a shock or
electrocution hazard.
Failure to comply with
the above warning
could result in death or
serious injury.
W-519
12
3
4
5
6
7
89

Blastmaster®121P Remote Control System
11
Installation:
Note: Additional components may be required to install the Blastmaster®121P Remote
Control System.
1) Locate the air flow direction arrow on Abrasive Trap (2), and install 1” NPT Close
Nipple (1) into inlet port.
2) Install 1” Close Nipple (3) into exit port of Abrasive Trap (2).
3) Install Outlet Valve (4) on 1” Close Nipple (3).
4) Install 1” NPT Close Nipple (1) on existing outlet piping, and install assembly on blast
pot.
5) Locate air flow directional arrow on Inlet Valve (11). Install existing inlet piping into
Outlet Port (A) of Inlet Valve. Install assembly on blast pot.
6) Connect 18” Pneumatic Control Line (5) to Outlet Valve (4) and Inlet Valve (11).
7) Connect Leg 1 (12) of Pneumatic Control Line (7) to fitting at bottom of Inlet Valve (11).
8) Connect Leg 2 (6) of Pneumatic Control Line (7) to fitting at top of Inlet Valve (11).
9) Install two Hose Unions (8) on Pneumatic Control Line (7).
10) Connect Pneumatic Control Line (9) to Hose Unions (8). Secure Pneumatic Control
Line (9) to abrasive blasting hose every 4 to 6 feet, and on each side of the hose
connections. Provide adequate slack at each connection.
11) Connect Pneumatic Control Line (9) to Pneumatic Remote Control Switch (10). (See
pneumatic remote control switch Operator’s Manual.)
INSTALLATION
Always depressurize
the entire system,
disconnect all power
sources and lockout/
tagout all components
before any maintenance
or troubleshooting is
attempted. Failure to
comply with the above
warning could cause
electrical shock and
inadvertent activation of
equipment resulting in
death or serious injury.
W-562
For equipment
manufactured by entities
other than Marco,
you must consult the
Original Equipment
Manufacturer operator’s
manuals, information,
training, instructions
and warnings, for the
proper and intended
use of all equipment.
Failure to comply with
the above warning
could result in death or
serious injury.
W-511
Pulling and dragging
abrasive blasting hose
may cause control
line and electric cord
connections to separate.
Connect the control line
and electrical cord to
the abrasive blasting
hose every 4 to 6 feet
and on each side of the
control line connections.
Provide adequate slack
at each connection.
N-516
Use a 16 gauge electric
cord for lengths up
to 100 feet. To reduce
electrical resistance, use
larger gauge electrical
cord for distances
greater than 100 feet.

Blastmaster®121P Remote Control System 12
INSTALLATION
A
1
10
11
2
3
4
5
6
7
8
912
8

Blastmaster®121P Remote Control System
13
Maintenance of the 1-1/2" Inlet Valve is limited to the daily cleaning and the immediate
replacement of damaged or worn parts.
Disassemble:
1) Remove Fittings (2,13,14) and Petcock (1). Clean or replace if damaged.
2) Remove Bottom Cap (10), Gasket (9), Spring (11), Spring (8), and Valve Plug
Assembly (6, 7, and 12) from Body (5).
3) Disassemble Valve Plug Assembly by turning Valve Plug Washer Retainer (6) counter
clockwise. Remove Valve Plug Washer (12) and inspect for damage.
4) Remove Cylinder Cap (16). Remove O-ring (3) and inspect for damage.
5) Push Piston and Rod Assembly (15) through top of Body (5). Inspect O-ring (4) for
damage.
MAINTENANCE
Disassemble and Assemble 1-1/2" Inlet Valve
Assemble:
1) Install O-ring (4) on Piston and Rod Assembly (15). Apply lubricant to O-ring and Piston.
2) Using a smooth motion, push Piston and Rod Assembly (15) into Body (5) until the
assembly is a depth of 1/2” from the top of the Body (5). Do not force the assembly as
damage can occur.
3) Place Valve Plug Washer (12) over stud on Valve Plug (7). Install Valve Plug Washer
Retainer (6) on stud of Valve Plug, turning clockwise. Do not over-tighten.
4) Place Body (5) upside down, install Valve Plug Assembly with Valve Plug Retainer (6)
toward Body. Place Spring (11) on Valve Plug (7). Insert Spring (8) inside Spring (11).
5) Place Gasket (9) on Body (5). Install Bottom Cap (10) over two Springs (8,11) and
thread into Body.
6) Lubricate O-ring (3) and place on bottom of Cylinder Cap (16). Install Cylinder Cap on
Body (5).
7) Apply pipe sealant to pipe threads of Fittings (2,13,14) and Petcock (1). Install into
appropriate ports.
Apply pipe thread
sealant to all pipe
threads to ensure an
airtight seal.
N-519
Always depressurize
the entire system,
disconnect all power
sources and lockout/
tagout all components
before any maintenance
or troubleshooting is
attempted. Failure to
comply with the above
warning could cause
electrical shock and
inadvertent activation of
equipment resulting in
death or serious injury.
W-562
Moving parts can
present an area where
crushing, pinching,
entanglement or
amputation may occur.
Do not place body parts
or foreign objects in any
area where there are
moving parts. Failure to
comply with the above
warning could result in
death or serious injury.
W-563
Never use compressed
air to separate or
remove internal
components during
maintenance.
Components could be
ejected at high speeds.
Failure to comply with
the above warning
could result in death or
serious injury.
W-529

Blastmaster®121P Remote Control System 14
MAINTENANCE
Disassemble and Assemble 1-1/2” Inlet Valve (cont)
1
10
11
12
13
14
15
16
2
3
4
5
6
7
8
9
2

Blastmaster®121P Remote Control System
15
MAINTENANCE
Apply pipe thread
sealant to all pipe
threads to ensure an
airtight seal.
N-519
Always depressurize
the entire system,
disconnect all power
sources and lockout/
tagout all components
before any maintenance
or troubleshooting is
attempted. Failure to
comply with the above
warning could cause
electrical shock and
inadvertent activation of
equipment resulting in
death or serious injury.
W-562
Moving parts can
present an area where
crushing, pinching,
entanglement or
amputation may occur.
Do not place body parts
or foreign objects in any
area where there are
moving parts. Failure to
comply with the above
warning could result in
death or serious injury.
W-563
Never use compressed
air to separate or
remove internal
components during
maintenance.
Components could be
ejected at high speeds.
Failure to comply with
the above warning
could result in death or
serious injury.
W-529
Disassemble and Assemble 1” Diaphragm Outlet Valve
Maintenance of the 1” Diaphragm Outlet Valve is limited to daily cleaning and immediate
replacement of damaged or worn parts.
1) Remove Nipple (7) from Body (6).
2) Remove Bushing (8) from Body (6).
3) Remove Elbow (1) from Body (6).
4) Remove Bolts (2), Lock Washers (3) and Cap (4) from Body (6).
5) Remove Diaphragm (5). Inspect for damage and replace as necessary.
6) Install parts in reverse order.

Blastmaster®121P Remote Control System 16
MAINTENANCE
1
2
3
4
5
6
7
8
2
3
Disassemble and Assemble Blastmaster®1” Diaphragm Outlet Valve (cont)

Blastmaster®121P Remote Control System
17
Disassemble and Assemble Abrasive Trap
Maintenance of the Abrasive Trap is limited to the daily cleaning and the immediate
replacement of damaged or worn parts.
Disassemble:
1) Remove Thumbscrew (1) by turning counter-clockwise.
2) Swing Cap Lock Bar (15) clear of Cap (3) and remove Shoulder Screws (2,16), Cap
Lock Bar, and Cap.
3) Remove O-ring (14) from Cap (3).
4) Remove Screen Gasket (4) from Cap (3). Inspect parts for damage and replace as
necessary.
5) Remove Abrasive Trap Screen (13) from upper chamber of Body (5). Clean or replace
as necessary.
6) Remove Thumbscrew (9) by turning counter-clockwise.
7) Swing Cap Lock Bar (7) clear of Cap (11) and remove Shoulder Screws (8,10), Cap
Lock Bar, and Cap.
8) Remove O-ring (6) from Cap (11).
9) Inspect 1” NPT Close Nipple (12). Replace as necessary.
Assemble:
1) Install 1" NPT Close Nipple (12) on air inlet side of Body (5).
2) Install Screen Gasket (4) in Cap (3). Install O-ring (14) on Cap.
3) Install Cap Lock Bar (15) using Shoulder Screw (2). Install Shoulder Screw (16) in
opposite hole.
4) Place Abrasive Trap Screen (13) with large opening of screen down. Ensure it sits in
recess of upper chamber of Body (5).
5) Install Cap (3) on Body (5), and move Cap Lock Bar (15) to rest against Shoulder
Screw (16).
6) Install Thumbscrew (1) and tighten.
7) Install Cap Lock Bar (7) using Shoulder Screw (10). Install Shoulder Screw (8) in
opposite hole.
8) Install O-ring (6) on Cap (11), and install Cap (11) on Body (5).
9) Move Cap Lock Bar (7) to rest against Shoulder Screw (8) and install Thumbscrew (9)
and tighten.
MAINTENANCE
Always depressurize
the entire system,
disconnect all power
sources and lockout/
tagout all components
before any maintenance
or troubleshooting is
attempted. Failure to
comply with the above
warning could cause
electrical shock and
inadvertent activation of
equipment resulting in
death or serious injury.
W-562
Moving parts can
present an area where
crushing, pinching,
entanglement or
amputation may occur.
Do not place body parts
or foreign objects in any
area where there are
moving parts. Failure to
comply with the above
warning could result in
death or serious injury.
W-563
Never use compressed
air to separate or
remove internal
components during
maintenance.
Components could be
ejected at high speeds.
Failure to comply with
the above warning
could result in death or
serious injury.
W-529

Blastmaster®121P Remote Control System 18
Disassemble and Assemble Abrasive Trap (cont)
9
8
7
6
5
4
3
2
1
15
14
13
12
11
10
16
MAINTENANCE

Blastmaster®121P Remote Control System
19
If the Blastmaster®121P Remote Control System does not function properly, check the
following:
SYMPTOM (Cause) ACTION
Blast pot will not pressurize
(Damaged components, Pneumatic
Control Line, Improper air supply)
Inspect pneumatic control lines for correct
routing, air leaks, blockage or pinch points.
Tighten control line fittings if leaks are
present. Replace damaged pneumatic
control lines.
Ensure petcock located on Inlet Valve is in
the closed position.
Insufficient air supply returning to Inlet Valve
from remote control switch. Open petcock on
Inlet Valve. Activate remote control switch,
air should exit from petcock. If air does
not exit petcock, inspect pneumatic control
lines for leaks or blockage. Refer to remote
control switch Operator’s Manual.
Ensure vent port on upper cylinder of Inlet
Valve is clear of obstruction. Clean vent port
if obstructed.
Insufficient air supply. Ensure minimum of
50 PSI is supplied to the valves.
Inspect Inlet Valve and Outlet Valve for
damage. Immediately replace damaged
components.
Refer to Operator’s Manual for remote
control switch and blast pot.
Inconsistent activation/
deactivation
(Damaged components, Pneumatic
control line)
Lubricate the Inlet Valve and Outlet Valve
by introducing lightweight oil through the
petcock on the Inlet Valve. This should be
performed weekly.
Inspect Inlet Valve, Outlet Valve, Abrasive
Trap, and all control lines for damage.
Replace damaged components immediately.
Ensure Control Air Fitting on lower portion of
Inlet Valve is not full port. Replace
immediately with 1/16” orifice restrictor fitting.
Frozen moisture could
cause restrictions
and obstructions in
pneumatic control
lines. Any restriction
or obstruction in the
pneumatic twinline
or single line hoses
could prevent the
proper activation and
deactivation of the
remote control system,
resulting in the release
of high speed abrasive
and compressed air.
In conditions where
moisture may freeze in
the pneumatic twinline
or single line hoses
an antifreeze injection
system approved for
this application can
be installed. Failure to
comply with the above
warning could result in
death or serious injury.
Do not cut, obstruct,
restrict or pinch
pneumatic twinline
or single line hoses.
Doing so could prevent
the proper activation
and deactivation of the
remote control system,
resulting in the release of
high speed abrasive and
compressed air. Failure
to comply with the above
warning could result in
death or serious injury.
Always depressurize
the entire system,
disconnect all power
sources and lockout/
tagout all components
before any maintenance
or troubleshooting is
attempted. Failure to
comply with the above
warning could cause
electrical shock and
inadvertent activation of
equipment resulting in
death or serious injury.
TROUBLESHOOTING