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Thermal Spray

For Internal use Only
For Internal use Only
Training Module Study Guide – Coating Processes
Process Selection
Eutalloy Model B Torch & UltraJet Eutalloy Torch
Thermal Spray Overview
RotoTec 1A
Terodyn 2000
Terodyn 3000
Castodyn DS 8000
TeroJet AC (HVOF) System
EuTronic GAP 375 PTA (Plasma Transferred Arc Welding) System
Safety and Health Considerations
Note: These Modules are intended to be used as a study guide prior to or in conjunction with
each part of the lecture portion of the Powder Training Course offered by the Eutectic Group.
Provided is background information and instructions that will aid in learning the details
provided in each process manual.
Be sure to study and understand the information in the process manuals before proceeding to
use the systems.
Applying the technologies of Welding and Coatings to the best advantage for industry is a
unique and important challenge. The recurring expense of maintaining industrial equipment
can be crippling to a company when traditional approaches are followed. By using available
technologies, control is added to the preventative maintenance program. Control that
traditionally was limited to scheduled shutdowns for replacing critical components before
failure is now extended to increase the service life of parts far beyond that of the original
Commonly recognized types of wear are:
Abrasion (2-body, 3-body, low stress, high stress)
Adhesive wear (scoring, galling, fretting)
Erosion (solid particle, liquid particle, fluid or gas)
Corrosion (liquids, vapors, and gases)
Impact and Fatigue
By using welding and coating technologies it is possible to lengthen the time between
scheduled shutdowns thereby increasing productivity. The fact that worn components can be
rebuilt by welding or coating, rather than being written off as scrap adds incremental savings
each time a part is rebuilt. Savings of course, translate into profits.
Maintenance and repair by welding or coating is not a new concept. However, these concepts
are often underutilized. There is merit to the old saying “if it works, don’t fix it”. This works for
many things used by individuals, cars, lawn mowers, bicycles, and such. It does not work in
industry where lost production far outweighs the convenience of not worrying about it until it
Exploring an overview of the concept, the following questions are key:
What is the problem?
How much does the problem cost?
Why is there a problem?
Which technology can be used to best manage the problem?
When should this technology be used?
Who should apply the technology?
The following examples are used to illustrate the concept.
What is the problem?
Part won’t work anymore.
Part doesn’t last long enough.
Replacement part is not available.
How much does the problem cost?
Value of lost production.
Value of lost business
Cost of replacement parts or equipment.
Installation costs of parts or equipment.
Why is there a problem?
Parts break.
Parts wear out.
Parts corrode.
Which technology can be used to best manage the problem?
Welding, brazing, or soldering can fix broken parts.
Worn out parts can restored to original dimensions by both welding and coating
The rate of wear can be controlled by process and alloy selection.
Wear is inevitable. Proper selection of coating or overlay can often control where
the wear occurs. In this way, parts that are easier to work on can be allowed to
wear first.
When should this technology be used?
Ideally, during scheduled downtime.
As part of the original equipment manufacturing.
For emergency repairs.
Who should apply the technology?
The most versatility is realized by on-site application by in-house employees.
On-site application by contractors.
Parts can be sent out to contractors for application and finishing.
Process Selection
The Eutectic Group maintains a database of Approved Application Procedures (AAP’s).
Literally thousands of solutions to industrial problems are documented, and available as
reference materials to support our commitment to improving the performance of industrial
components by prolonging their usable life span.
This reduces the amounts of scrap generated by industry, preserves natural resources, and
controls costs associated with operation of machinery and equipment.
AAP’s are available for the entire realm of processes recommended by the Group. These
include the following:
SMAW – Stick Welding
GMAW – Wire Welding (MIG)
GTAW – Wire Welding (TIG)
PTAW – Plasma Transferred Arc Welding
(EuTronic GAP 375 Powder Welding Process)
Thermal Spray Coating – Fusion Powder Process
(Eutalloy, RotoTec, Terodyn, Castodyn)
Thermal Spray Coating – Cold Spray Powder Process
(RotoTec, Terodyn, Castodyn, HVOF)
Composite Adhesives – Abracor
(Two part epoxy-composite materials)
Wear Plates (Hardfacing Weld Overlay on Steel Plates)
Build up overlays
Hardfacing overlays
Solid Wires
Flux Cored Wires
Metal Cored Wires
Build up overlays
Tool & Die Alloys
Build up overlays
Hardfacing overlays
Build up coatings
Hardfacing Coatings
Build up Coatings
Corrosion Control Coatings
Wear Resistant Coatings
Metal Filled Build up
Wear Resistant Coatings
Emergency Repair Coatings
Full Plates
Custom Cut Plate
Fabricated Anti-wear Parts
AAP’s can be searched by different parameters such as: process, part, industry, country, and
etc. Confidentiality is ensured by license.
The Eutalloy Processes
The Eutalloy Process was introduced by Eutectic in 1963 as a way to braze or overlay using
a metal powder feedstock. Since then it has been refined into one of the most versatile
oxyacetylene processes for repairing and protecting surfaces, edges, corners, holes, threads
and key-ways made of most common alloys. In fact the model B system has attachments
available for cutting and standard brazing as well as for the powder process. The Eutalloy
Process uses the Low Heat Input principle developed by the Eutectic+Castolin Institute.
Specially formulated fusible powder alloys with near eutectic compositions are used. The
melting characteristics of theses alloy allow surface alloying to take place well below the melt
point of the base metal. Thus a fully dense, metallurgically bonded overlay coating can be
applied, quickly and easily.
All of the Eutalloy Systems are engineered to be easy to use and serviceable by the user.
The table below summarizes system configuration and features.
Model B
Basic system
Model C
Water cooled system
Up-dated precision
Model S
High production
rate system
Four tip sizes for small to large jobs. Available
attachments for powder overlays, cutting, and
standard brazing.
Two tip sizes for continuous production work, and
high deposition rates.
Seven tip sizes with matching precision gas
mixer/aspirator assemblies. Available water-cooled
tips. Instant on-off gas trigger for quick, easy ignition
and shutdown.
New tip & gas mixer designs operate at 60-psi
oxygen and 15-psi acetylene provides more heat
and higher feed rates to improve productivity.
The Eutalloy Systems are easy to set up and use. They require oxygen and acetylene gases
properly regulated to the correct pressure settings. The torch is supplied with reverse flow
check valves. Oxygen is used to aspirate the powder. This virtually eliminates any chance of
acetylene entering the powder module.
To operate the systems set gas pressures according to the following table and instructions.
Connect the torch to gas supply regulators.
Light torch as you would a standard oxyacetylene torch. Crack the oxygen valve
and open acetylene valve ¼ turn.
Ignite immediately, and adjust valves for proper flame.
Recheck pressures at regulators, open acetylene valve fully, and adjust final
flame to neutral with the powder feed lever depressed.
Be sure to wear eye protection (shades 3-6 recommended).
If a backfire or flash back should occur turn off acetylene immediately and check
all equipment before relighting.
Tip Size
53 Model B
2-3 psi
48 Model B
4-5 psi
45 Model B
5-6 psi
Multi-orifice Model B
10 psi
34 Model C Water cooled
10 psi
A1 UltraJet
7.5 psi
A2 UltraJet
7.5 psi
B3 UltraJet
7.5 psi
B4 UltraJet
7.5 psi
C5 UltraJet
7.5 psi
C6 UltraJet Water
7.5 psi
Multi-orifice UltraJet
15 psi
“NEW” UltraJet Model S5
15-18 psi
25-30 psi
25-30 psi
50 psi
18 psi
22 psi
30 psi
30 psi
30 psi
30 psi
30 psi
30 psi
60 psi
Fine work, carbide tip available
Medium work, carbide tip available
Larger work, carbide tip available
Large work, high spray rate
Large work, continuous use.
Brazed carbide extension available.
Carbide insert tip available.
Carbide insert tip available.
Carbide insert tip available.
Carbide insert tip available.
Carbide insert tip available.
Large work, continuous use.
Highest productivity.
The Eutalloy powder module is designed to fit the module opening on the torch. Remove the
module cap; invert the torch and insert into the module opening with a ¼ turn to lock. This
module protects powders from contamination, eliminates the need for a transfer funnel and
helps to minimize exposure to air-born powder associated with a filling operation. As an
option, a metallic module (or hopper) with a positive sealing cap is available. Use of proper
ventilation and a respirator rated N-95 or N-100 is required during spray and powder handling
Prior to coating, the base metal (part) must be prepared. Degreasing, followed by grinding or
blast cleaning is normally used. Some cast iron may be saturated with oil and require heating
or vapor degreasing to remove all traces of oil or other contaminants. Pre-heat the part to
about 400 to 800oF and spray a thin layer of powder, from about 1” standoff distance, to cover
the desired area.
If a thin layer is all that is needed, simply continue heating the coated surface (without feeding
powder) with a slightly carburizing flame. Shortly after red heat is attained, the coating will
become glassy looking and smooth. This is the fusing point. Do not overheat beyond this
temperature or the alloy will become liquid and sag or run off the surface.
If a thicker layer is required, at the first sign of red heat, move the torch tip to within ¼” to ¾”
and begin applying powder in short bursts while slowly moving the torch over the starting area.
Once the fusing temperature is indicated by the smooth glassy looking appearance, begin to
add more powder and to advance the torch in a weaving motion at a speed suitable to
maintain the correct fusing temperature. This process, like any brazing process, is subject to
hand, eye coordination. With practice it will become second nature to balance powder feed,
travel, and heat to obtain the coating deposit you desire.
When less heat is needed, use a smaller tip. Cutting back the gases to choke the flame will
cause the tip to overheat and back fire, or flash back. Generally, coated parts should be slow
Powders available for use with the Eutalloy process include:
10680 – Machineable, build up alloy. HRC 15
10224 – Machineable, build up alloy. HRB 90
10185 – Machineable, tough, hardfacing alloy. HRC 40
10009 – Hardfacing, corrosion resistant alloy. HRC 60
10092 – Tough hardfacing alloy for elevated temperature service. HRC 50
10999 – Hardfacing alloy with carbides for fine particle abrasion. HRA 80+
10112 – Hardfacing tungsten carbide alloy with best abrasion resistance.
10011 – Hardfacing alloy with 80% coarse tungsten carbide.
Thermal Spray Overview
Thermal spray coatings can be applied by a variety of methods. Coatings are applied to the
desired thickness at temperatures that do not overly stress or change the base metal
properties. We refer to this as “cold-process”, meaning that the part should not exceed 500o F
during coating. Keep in mind that subsequent fusing or heat-treating will affect the base metal
properties. Eutectic categorizes thermal spray powders into the following groups.
“One-step” self-bonding alloys that bond and build up.
“Two-step” alloys for build up only (require separate bond coat).
Spray and fuse (“hot-process”) alloys for build up and hard facing.
Low temperature alloys for corrosion control and part restoration.
A group of powders is available with compositions “like” those used for the Eutalloy process.
Coatings applied with these fusible powders can be heated to the fusing range where they will
solidify to full density and form a metallurgical bond with the base metal. Fused coatings are
more durable than other coatings. However, they require a great deal of heat input for fusing.
This often makes fusing impractical on very large parts. Very large parts requiring coatings
with this degree of durability or wear resistance can often coated by PTA welding or
conventional welding processes. Remember that there is an order of magnitude difference
between mechanical bonding (“cold-process”) and metallurgical bonding (“hot-process” spray
or welded). That is to say 5,000 psi versus 50,000 psi or more, respectively.
Thermal spray has evolved from feeding a wire through an air assisted oxy-fuel torch, to twinarc wire systems, combustion powder systems, plasma spray systems and finally high velocity
systems otherwise known as HVOF (High Velocity Oxygen Fuel) systems. All of the Eutectic
thermal spray systems currently available can be classified in the combustion thermal spray
category using powder feed stocks. They include the RotoTec 1A, Terodyn 2000 & 3000,
the Castodyn DS 8000, and the Terojet systems. Each system has unique features and
can be targeted toward customers with different needs.
Small and medium sized shops that will work mostly coating shafting can benefit most by
starting out with the RotoTec 1A system. Its low capital cost and very functional, proven,
capabilities make it a very attractive package. Its limitations are related to coating rate and
that only a limited range of metallic coatings can be used.
Medium and large sized shops who will have steady coating jobs on a variety of parts can
benefit most by acquisition of the Terodyn 2000 or DS 8000 systems.
These offer the ability to spray a wide variety of coating types, including metals, ceramics,
polymers and low melting point metals such as babbit and zinc. The Terodyn 3000 system
has additional advantages for the larger sized shop who specialize in thermal spraying. Its
remote powder feeder with large powder capacity is ideal for big coating jobs and allows
operation in any position, including overhead or inverted.
Many customers demand the extreme wear resistance offered by Eutalloy powders
containing tungsten carbide, on large parts. Until the advent of HVOF this was not possible
without tremendous heat input and changes to the metallurgy of the parts.
Coatings based on tungsten carbide can be applied by the Terojet system at low temperatures
with exceptional bond strength. Tungsten carbides applied by HVOF offer the best resistance
to most abrasion and erosion that is possible in a coating. Pure carbide inserts can be brazed
in place and will offer better abrasion resistance and hardness. However, inserts are only
practical on a small scale before the costs become prohibitive.
The basic procedure for applying thermal spray coatings is summarized as follows:
Surface cleaning to remove grease, oil, paint, or previous coatings.
Surface preparation to remove damaged base metal and undercut the area to
accommodate the added coating dimension.
Masking may be required before grit blasting to protect areas that are not to be
Surface roughening to increase the available surface area for bonding and to
provide an anchor pattern to lock the coating in place. This can be done by
threading, grinding or by the preferred method, grit blasting. Grit blasting with 24
grit aluminum oxide (corundum), illmenite, or 16 grit angular chilled iron give the
best results and the greatest safety factor.
Masking may be required prior to coating. Eutectic hi-temp tape, shadow
masks, Eutectic Solution 103, or other suitable means can be used.
Spray torches with adjustable powder feed rate control should be checked before
starting the job. Spray rate should be within 10% of the rate shown in parameter
Preheating, generally to between 150oF and 300oF depending on the part
geometry and the powder being used. 200oF is a safe temperature to begin
almost all coatings. Ceramics and polymers being the notable exceptions.
Apply coating to corners or edges first. Angle the torch to wrap coating around
edges. Cover the balance of the part with the bond pass or bond coat.
Build up the coating by making multiple overlapping passes. The coating quality
will be best when applied in thin layers. Traverse speeds and/or rotational
speeds should be set to apply coating at a rate of less than 0.004” thickness per
pass. Traverse speeds on flat parts should be on the order of 3 to 6” per second.
Rotational speed of cylinders should be between 150 and 200 sfpm (on smaller
diameters this may be lowered to 75 sfpm) with a travel rate of 0.125” to 0.25”
per revolution.
Maintain temperature below 500oF, pause to allow coating / part to cool when
needed. Use of auxiliary cooling air is recommended.
The RotoTec 1A
The RotoTec torch was introduced by Eutectic in 1971. Over the years the design has
changed from the originally patented model I to the model II and to the current model, the 1A.
The model 1A is designed to apply metallic alloys (except zinc, aluminum and babbit) including
the self-bonding one step powders. A conversion kit is available to upgrade the older models.
The RotoTec 1A is affordable, simple to use, and very effective for rebuilding shaft bearing
areas. Powders are packed in modules that fit on top of the torch. Powders feed by gravity
into the flame, which heats and propels particles onto the part.
To operate the torch, follow these instructions:
Connect the torch to gas supply regulators.
Set oxygen regulator to 20 psi and acetylene regulator to 8 psi.
Light torch as you would a standard oxyacetylene torch; crack the oxygen valve
and open acetylene valve ¼ turn.
Ignite immediately, and adjust acetylene and then oxygen to full flow. This will
give a slightly oxidizing flame
Be sure to wear eye protection (shade 5 or higher).
If a backfire or flash back should occur turn off acetylene immediately and check
all equipment before relighting.
Powders available for use with the RotoTec process include:
19121 – General-purpose “one-step” powder.
19122 – Machinable general-purpose “one-step” powder.
19131 – Machinable corrosion resistant “one-step” powder.
19132 – Hard, corrosion resistant “one-step” powder.
19171 – General-purpose bronze “one-step” powder.
Spray and fuse powders can also be applied with the RotoTec system:
13494 – Nickel chrome boron HRC 40
13495 – Nickel chrome boron HRC 50
13496 – Nickel chrome boron HRC 60
The following “two-step” powders can also be used to build up parts. They must be used only
after application of the bond coat powder UltraBond 50000.
29011 – 316 stainless steel (Austenitic) HRB 90.
29012 – 400 type stainless steel (Martensitic) HRC 35.
29021 – Durable nickel chrome aluminum alloy HRC 32.
29061 – Machinable bronze powder HRB 65.
29077 – Low alloy steel powder HRB 85.
29096 – Machinable nickel chrome alloy for thick build-ups HRB 82.
The TeroDyn 2000
Eutectic+Castolin introduced the TeroDyn 2000 in the early 1980’s as the CastoDyn 2000,
which was an improved version of the Rotoloy torch. In 1984 the design was modified and
the TeroDyn 2000 series 2000 was born. It has the most value based on cost and
performance of any torch available in any market worldwide. Some European Countries have
standards that do not allow acetylene to be used above 10 psi. The
DS 8000 system is used exclusively in these countries.
The TD 2000 is a thermal spray “work horse”. The torch body is forged bronze, precision
machined and plated. It is built to last, and does, with many of the original units still operation
after 20 years or more. Designed to be the most versatile powder alloy delivery system
available. Its features, controls, accessories and capabilities are impressive. Understanding
the following illustration of the system, and description of functional parts, is essential prior to
learning about its more advanced accessories, features and benefits.
Standard packaging for most powder alloys. Locks into the
Module Adapter (item 2) by a quarter of a turn.
Mounts MegaPaks to the delivery system. The Basic Kit comes
with 2 adapters. The material being deposited and coating rate
will determine the appropriate adapter.
Starts and stops the flow of powder into the delivery system.
Green dot indicates alloy is feeding, red dot indicates no feed.
Access plug for cleaning powder alloy aspirator. Must be tight
at all times.
Transport Valve-controls the flow rate of the carrier gas and
powder alloy. Valve position varies with material being applied.
Oxygen valve-Controls the flow of oxygen into the flame. It is
adjusted until the number indicated on the FM-1 Flowmeter
agrees with the figure published in the Coating Tables.
Acetylene valve-Controls the flow of acetylene into the flame. It
is adjusted until the number indicated on the FM-1 Flowmeter
agrees with the figure published in the Coating Tables.
Right-hand thread connection for oxygen line includes Flo-Safe
Reverse Flow Check Valve.
Left-hand thread connection for acetylene line includes FloSafe Reverse Flow Check Valve.
Controls the flow of oxygen & acetylene. In the forward position
gases are flowing, in the backward position the flow of both
acetylene and oxygen are stopped.
For machine mounting the delivery unit.
Combines oxygen and fuel gasses to produce a combustible
mixture for the nozzle.
Secures nozzle to gas mixer.
Forms proper flame and introduces materials into the flame.
Two nozzles are supplied with the Basic Kit (RL 200 and RL
210); use the nozzle specified in the Coating Table for the
material being applied.
Upper heat shield protects MegaPak, lower heat shield protects
the operators hand from the heat generated during continuous
coating operations.
Secures the gas mixer assembly to the delivery unit
Only genuine Eutectic powders are recommended for use with the TD2000. However, over
the years it has been found that, because the torch is so versatile, parameters can be
developed for almost any powder. Technical service can offer advice on what is possible.
Installation of the TD 2000 is somewhat more complicated than either the RotoTec 1A or the
DS 8000. Due to the volume of acetylene used, cylinders must be manifolded to ensure that
the system functions safely. To ensure coating quality given the wide variety of powders and
accessories an inline flow meter for oxygen and fuel, and compressed air are required as
shown in the following illustrations.
The TeroDyn 2000 System Complete Kit contains everything needed to begin coating parts,
except the powder. To operate the system set it up as above.
Find the parameter settings for the powder to be used in the process manual.
Print this table for reference.
Attach the nozzle and RotoJet specified. If the RPA-1 is being used the air must
be turned on before lighting the torch or it may damaged by melting.
Make sure the gas on-off trigger is in the off (back) position and the gas valves
are closed.
Set the oxygen and fuel gas regulators to the required pressures.
Open the powder container and attach the correct module adapter (yellow/red or
aqua) to the powder container. Make sure the powder on-off lever is off (shows
red indicator).
Set the T-Valve to the specified click setting range. Anytime the T-Valve is
changed be sure to re-check the oxygen flow and adjust as needed.
Crack the oxygen valve and open the fuel valve ¼ to ½ turn and ignite. Increase
fuel then oxygen so the flow meter reads the values specified in the table.
Check that there is suction at the powder inlet on top of the torch using your
finger. If not check to see that the T-Valve is not set on zero.
Invert the powder container and attach to the torch by sliding it into place.
If the air to the RotoJet is off, turn it on and check that the pressure is set as per
the parameter table.
Be sure you are wearing the shade 5 safety glasses included in the kit before
starting to spray.
To start spraying, push the powder feed lever forward so it shows “green”.
Remember to check surface preparation before coating.
Remember to check powder feed rate at the beginning of each shift or job.
Features and benefits of the TeroDyn 2000 system
Critical seals are O-rings
Mixed gas path is short
Positive flow of oxygen carrier gas
Reverse flow check valves included
Gas on / off control lever
Any leaks easy to find and fix
Less chance of flash-back
Prohibits presence of fuel gas in powder module
Prevent any back flow of gases into gas supplies
Allows instant shut off of oxygen and fuel with
one control
Rugged construction
Precision powder transport valve
In-line flow meter
Service life of decades rather than years
Consistent powder feed rates
Makes setting flame accurate and repeatable.
Several precision multi-orifice nozzles Control of heat transfer characteristics expands
the range of coating materials that can be used
Flexibility to increase powder velocity, focus
Air circuit RotoJet attachments
spray pattern and cool the part
LT Air Shroud
Allows low melting point metals and polymers
to be applied
LT Extender
Allows coating of internal diameters or hard to
reach places
Module adapters
Two adapters allow control of all powders
including ceramics, metals and polymers.
Allows out of position coating up to 75 above or
below horizontal
Tool post stud and attachment
Easy to mount torch on lathe tool post or other
Multiple fuel gas operation
Capability to use acetylene, MAPP, propylene,
propane, natural gas or hydrogen to lower
operating costs or for safety and convenience
Powders available for use with the TeroDyn 2000 (and the TeroDyn 3000) system include,
but are not limited to:
Self-bonding “one step” alloys
Multi-purpose material
Machinable build up
Iron base machinable
High temperature service
Hard corrosion resistant
General purpose bronze
Spray and fuse alloys
35% Tungsten carbide - coarse
Nickel chrome boron HRC 59
Nickel chrome boron corrosion resistant
40% Tungsten carbide - fine
High temperature materials (ceramics)
Aluminum oxide
Alumina 87 Titania 13
Titanium dioxide
Chrome oxide
Alumina 60 Titania 40
Zirconia 70 Alumina 30
“Two step” build up alloys
300 type stainless steel
400 type stainless steel
Aluminum bronze
Nickel chrome iron
75% Tungsten carbide
Low temperature materials
Aluminum 12 silicon
Babbit (tin, grade 2)
Zinc, bulk pkg.
Nylon 11, white
Methacrylic polymer
The TeroDyn 3000
The TeroDyn 3000 System was developed concurrently with the 2000 series. It uses the
same bronze forging and common parts. In fact, the TD2000 can be upgraded to the 3000
model. The following photo shows the TD3000 and the 5102 powder feeder
Notice modifications to the torch body. The module adapter saddle, the T-valve and the handle
are not used. An adapter to accept the external powder feed hose is added and the handle
changed to include a powder start/stop switch. All of the attachments available for the TD2000
will fit the TD3000.
Set up of the TD3000 is quite similar to that for the TD2000. The flow meter has a high
capacity fuel gas tube and the system comes with two 25-foot twin gas hoses instead of the
standard 12-foot hoses supplied with other torches.
To begin producing coatings the following are required:
TeroDyn 3000 Basic Kit (#4484757)
Carrier Gas Regulator (4615000)
Step-by-step operational procedures are available in the Process manual for the TD 3000 and
TecFlo 5102 powder feeder. During the hands on portion of the TD 3000 training all
procedures as well as maintenance will be thoroughly explained demonstrated and practiced.
The principal of operation of the feeder is the fluidized bed. Carrier gas is divided into two
streams. Both fluidizing and transport streams are controlled by the carrier gas flow meter.
Adjusting the pressure of the carrier gas in the powder hopper sets the powder spray rate.
This is regulated, along with the gas flow rate, on the front panel of the 5102 feeder.
The powder feed parameters have been developed using argon as the carrier gas. This was
done because the 5102 and 7102 are also used for plasma non-transferred arc thermal
spraying. The recently discontinued Eutectic Plasma 5000 system used argon as the primary
plasma gas and hydrogen as the secondary gas. Argon was used as the carrier gas for
Plasma Non-Transferred Arc: Manual coating of a tube-sheet for protection against high temperature oxidation.
When using with the TD 3000 it is desirable to utilize nitrogen as the carrier gas because it is
about 1/3 the cost of argon. Due to the physical nature of argon it is able to transport more
powder on a pound per cubic foot per hour basis. Therefore it is very important to verify the
spray rate before starting a coating job. A more detailed description will be presented during
the hands-on training session for powder products and equipment.
Note that an important feature of the DS 8000 is that it can be adapted to utilized the 5102
feeder. This capability gives the DS8000 most of the benefits found in the TD 3000 in an
easier to set-up and use package.
Features and benefits of the TeroDyn 3000 system
Critical seals are O-rings
Mixed gas path is short
Positive flow of carrier gas
Reverse flow check valves included
Gas on / off control lever
Quick disconnects with O-ring seals
Low voltage remote switching to
start and stop powder feed.
Any leaks easy to find and fix
Less chance of flashback.
Keeps powder delivery hose from clogging and
ensures that fuel gas can never back up into the
powder hopper.
Prevent any back flow of gases into gas supplies.
Allows instant shut off of oxygen and fuel with one
Prevents the powder hopper from being over
In case of electric shock voltage has been stepped
down from 115V to 12V.
Rugged construction
No moving parts in powder feeder
In-line flow meter
Meets US Military Specifications
(Mil Std 2138 & 1687)
Color coded inlets to powder
Service life of decades rather than years.
Less parts to wear and be replaced.
Makes setting flame accurate and repeatable.
Quality, traceability, and performance is backed up by
extensive research and testing
Ensures correct connections for proper operation of
powder feed.
Several precision multi-orifice
Air circuit RotoJet attachments
LT Air Shroud
LT Extender
External (remote) powder feeder
Tool post stud and attachment
Multiple fuel gas operation
Multiple switching control
Control of heat transfer characteristics expands the
range of coating materials that can be used
Flexibility to increase powder velocity, focus spray
pattern and cool the part
Allows low melting point metals and polymers to be
Allows coating of internal diameters or hard to reach
Allows coatings to be applied in any position by hand
or robotically.
Easy to mount torch on lathe tool post, positioner or
Capability to use acetylene, MAPP, propylene,
propane, natural gas or hydrogen to lower operating
costs or for safety and convenience
5102 or 7102 feeders can be used for combustion or
plasma spraying.
Other features
Can deliver up to 140,000 Btu/hr
Fluidized feeder design
Large powder feeder capacity
Dual powder pick up tubes on all
7102 Feeder available
Allows coating rates of up to 45 lbs/hour.
Metal, polymer and ceramic powders can be applied,
even when the powder is not free flowing or is to fine
to feed by gravity or venturi.
Ideal for extended use and large coating jobs.
Allows use of two TD3000 torches at the same time
(slaved) with the 5102 feeder.
Allows use of two torches (or two pairs of torches)
operating independently
The CastoDyn DS 8000
The DS 8000 thermal spray system is an innovative redesign of the RotoTec 800. It
incorporates a user friendly modular design concept. There are four standard spray modules
(SSM’s). Each is used specifically for a certain group of powder products. A durable carrying
case keeps all components organized and well-protected during transport or storage. Use of
precision laser drilled orifices in both gas mixing and powder delivery components ensure
consistent results without the need for an inline flowmeter. Optional accessories include two
models of spray and fuse lance attachments, an extension neck for coating internal diameters,
and fittings to allow use of a remote powder feeder such as the TecFlo 5102.
The DS 8000 can apply the full range of powder alloys supplied by Eutectic for conventional
combustion thermal spraying.
Features and benefits of the CastoDyn DS 8000 system
Critical seals are O-rings
Mixed gas path is short
Positive flow of oxygen carrier gas
Reverse flow check valves included
Gas on / off control lever
Operates at 10 psi acetylene
Any leaks easy to find and fix
Less chance of flash-back
Prohibits presence of fuel gas in powder module
Prevent any back flow of gases into gas supplies
Allows instant shut off of oxygen and fuel with
one control
Greater safety factor since acetylene becomes
unstable above 15 psi and allows safe operation
without requiring manifolded acetylene cylinders
Laser drilled precision orifices
The most consistent powder and gas feed
rates possible
Easy operation, fewer variables to adjust
Less operator fatigue leads to better
coatings and consistent productivity
Modular design principle
Light weight
Four Standard Spray Modules
Each module optimized for a specific
group of powders (gas mixer, nozzle,
and air focus attachment)
Allows coating of internal diameters or
hard to reach places
A single adapter with six settings allows
control of feed rate for all powders,
including ceramics, metals and polymers
For PTA quality deposits with lower
capital expense.
Good for out of position coating and long
spraying runs.
Extension neck
Module adapter
Spray and fuse attachment
External powder feeder plug in
The DS 8000 is a Swiss design made in Europe, and has, for the last several years been
available in North America. We rarely keep more than one of these systems in stock in the
US, so take this into consideration when accepting an order.
TeroJet Model AC
The TeroJet Model AC is a new generation High Velocity Oxy Fuel powder spray system
designed to apply high quality carbide and metallic coatings. The system is simple in design,
efficient in operation, and easy to use and maintain. This combination of features makes the
TeroJet AC suitable for both production, machine mount applications, as well as, for handheld occasional use.
The TeroJet has been designed to be as economical as possible for a true HVOF system.
Several features make this possible. First, the torch is air cooled so there is no need for a
water pump. Air-cooling simplifies the design of the torch making it less expensive to produce.
Second, the torch uses compressed gas as the fuel, typically propane or propylene. Kerosene
based systems require an expensive high-pressure pump plus controls to balance the oxygen
and kerosene. Lighting is done manually, eliminating the need for an internal ignition system
that only adds cost and complexity to the system. The result is a system with a low
capitalization cost and a low hourly operating cost.
The TeroJet torch uses a novel air cap design to “choke” the gas flow thereby generating a
high gas exit velocity. In its operating mode seven shock diamonds are visible in the
combustion gas stream. A high combustion gas exit velocity insures that the coatings
produced will be dense and low in porosity, will exhibit a high microhardness and associated
resistance to abrasion and will be well bonded to a properly prepared base material.
The powder and carrier gas enters the torch axially. This feature insures efficient heating and
acceleration of the powder coupled with minimal wear of the internal parts of the torch nozzle.
The use of a nozzle with air cap as compared to a long barrel typical of kerosene systems
minimizes loading of the powder onto the internal parts of the torch. Interrupting the spray
process to replace worn or clogged barrels can be costly and time consuming. The design of
the TeroJet AC torch virtually eliminates this problem.
Regulated flows of oxygen and fuel gas are delivered to the torch in the correct proportions
and a flame is developed. Compressed air restricts the flame, cools the torch and “blasts” the
powder particles to produce a fine, high velocity spray. The combination of the nozzle design,
air cap design and high pressure compressed air create the supersonic gas stream as
evidenced by the visible shock diamonds.
The system includes a highly precise, rotating disc powder feeder that accurately and reliably
delivers powder to the torch where it is axially fed into the combustion gas stream. The
inclusion of regulators and gas flow meters designed to match the requirements of the torch
insure that process parameters are tightly controlled.
The system is capable of applying tungsten carbide, chromium carbide plus metallic powder
blends, metallic and fusible powders. Further, the system can accommodate both –45 + 15µm
and –53 + 20µm size powders, the two most common size ranges commercially available.
However, the finer, -45 + 15 µm range powder is preferred as it will yield denser coatings.
Typical powder spray rates for the TeroJet AC are 5 lb/hr for carbides and up to 8 lb/hr for
metallics. The nominal deposit efficiency is 70%.
The Model PF 700 powder feeder is the latest in a series of designs specifically tailored for the
thermal spray process. The system is capable of delivering a steady, non-pulsating supply of
powder to the torch. The PF 700 operates on a volumetric feed principle. At the bottom of the
pressurized canister there is a rotating metal disc (slotted wheel) mounted off center with
respect to the canister. A given volume of powder fits into each slot and as the disc rotates
past the exit port, the powder is fed into the powder hose and then to the torch. The feed rate
of the powder (g/min, lb/hr, etc.) is governed by the rpm’s of the rotating disc. The disc is
driven by a precision control, geared, variable speed AC motor and the rpm is displayed on the
LED located on the control console front panel. The actual rpm of the disc equals the LED
displayed reading divided by 100.
Powders suitable for use with the TJ AC system include the following:
CPP 2506
88% WC + 12% Cobalt
88% WC + 12% Cobalt (finer particle size)
83% WC + 17% Cobalt
75% Chromium Carbide + 25% Nickel Chromium alloy
316 type stainless steel
Nickel alloy 625
Nickel Chromium Boron alloy (use as sprayed or fused)
EuTronic GAP 375 PTA Welding System
In the late 1970’s Eutectic launched the its first plasma transferred arc welding systems in the
USA. These were imported from Castolin + Eutectic in France. While the Servomatec 1 and
2 were state of the art at the time, they were also bulky systems best adapted to fixed
installations. By the mid1980’s Eutectic redesigned the French system and started
production. Success of the US GAP System was limited due its lack of portability and several
minor design flaws, which required excessive warranty service. Production was halted and a
major redesign program begun.
In 1988 after extensive field testing, the first EuTronic GAP 375 systems rolled off the
production line. Major advances in inverter-converter power source technology reduced the
size and weight of the system. Patented fluidized powder feeding, a solid-state programmable
controller, and Kooltronic water cooler round out the system.
The GAP 375 System is capable of meeting the requirements of the United States Military. It
has been supplied for Naval Shipyard use as per Bid Solicitation Contracts as governed by
Defense General Supply Center (DGSC) purchase order.
The GAP 375 system is compact and, for hand-held operation is easily as portable as the two
compressed gas cylinders required for operation. On-going design was finalized with the
advent of several models of welding torches. These fill the needs of almost all applications
that are practical in the scope of both OEM and M & R sectors of industry.
The GAP system functions by having argon carry a controlled amount of powder alloy into an
argon – 7% hydrogen shielded, transferred arc plasma column. The result is a precise weld
deposit with minimal heat affected zone and low dilution of the weld by the base metal.
EuTronic GAP System 375 Torches. From top to bottom: the E-90, 200, 220HP, 250, and 300HP torches.
The high frequency (HF) between the anode and cathode (tungsten) creates a pilot arc when
the system is started. When the torch is brought into position above the work piece the arc
transfers and the controller ramps the power and gas flows up initiating the plasma arc column
formation. Powder can be started manually or automatically started by the controller as
desired. The illustration below serves as a basic summary of operation.
The basic system includes the hand-held E-90 Torch. For practical purposes this functions
very similar to a TIG Torch that welds with powder instead of a rod. There are two main
advantages to welding with powder rather than wire or rod.
Powders can be made from materials that cannot be drawn into wire or rod. This
includes Tungsten carbides, Chromium carbides, and special formulations for
welding on cast iron and bronze.
Single pass deposits can often be used and can be more uniform in crosssection than wire welds for easier finishing with no slag to chip.
Conveyor Screw as welded with the GAP 375 System
Stick welding and MIG welding often require 2 or more weld passes before a hard-facing
overlay will reach the optimum hardness and wear resistance. This is due to the volume
percentage of dilution with the base metal. Generally the higher the percentage of dilution the
lower the deposit hardness and the greater the heat affected zone. This is illustrated below
with comparable cobalt base alloys, by process.
Deposits and the low carbon steel base metals below are acid etched for contrast
Oxy-Fuel Gas Weld: 2 lbs/hour with 1% Dilution
PTA Weld: 4 lbs/hour with 4% Dilution
SMAW (stick welding): 3 lbs/hour with 38% Dilution
GMAW (MIG welding): 5 lbs/hour with 31% Dilution
Features and benefits of the EuTronic GAP System 375
Operates on multiple phase or voltages.
Lightweight and compact, hand-held or
machine mounted capabilities.
Built-in safety sensors monitor gas flows
and cooling water flow.
Uses powder alloys, not wire or rod.
Applies thin (1/16”) or thick (3/16”) coating
deposits in a single weld pass faster than
is possible with TIG or Oxy-Fuel welding.
Custom wiring not usually required.
Extremely stable weld current over the
entire ranges (10 – 375 Amps).
Perfect for on site jobs, mobile platforms
and fixed robotic installations.
Minimizes cost of repairs due to operator
Gives a wider variety of coating solutions
to best control the wear process. This
leads to better over-all cost effectiveness.
Yields better productivity.
Powders suitable for use with the GAP system include, but are not limited to:
Gas Atomized alloys
Stainless steels (16300LC, 16410)
Nickel-base alloys (16801, 16804, 16805)
Maraging steel (16550)
Tool steels (16725)
Cobalt-base alloys (16001, 16006, 16012, 16021)
Water Atomized alloys
Nickel – Silicon – Boron (5056)
Nickel – Chrome – Boron (16494, 16495, 16496)
Blends of Metallic and inter-metallic powders
Ni-Cr-B plus Tungsten carbide (16112, 16113)
Ni-Si-B proprietary blends (16220, 16221, 16227)
Nickel alloy plus Chromium carbide (16114)
Special compositions or blends can be custom made, or made to industry specifications as
required. Custom-made alloys are subject to minimum order requirements and/or special
pricing and/or special delivery terms and conditions.
When Arc Welding, Plasma Transferred Arc Welding or Plasma Non-Transferred ArcThermal Spraying
Fumes and Gases can be dangerous to your health. Medical studies suggest that
Lung Damage and/or CNS effects can result from exposure to welding fumes and
gases. Brazing, soldering, and thermal spraying may have similar effects.
Keep your head out of the fumes.
Use enough ventilation, exhaust at the source, or both to keep fumes away
from your breathing zone and the general area.
Wear correct eye, ear, and body protection.
Before use, read and understand the manufacturer’s instructions, Material
Safety Data Sheets (MSDS’s), and your employer’s safety practices.
Light rays, heat rays (ultraviolet and infrared radiation) and sparks from the arc or
flame and hot metal can injure eyes, burn skin and may ignite combustible
materials in the area.
Do not touch live electrical parts.
Wear dry insulating gloves in, good condition, and protective clothing.
Properly install and ground the equipment according to the manufacturer’s
instructions and federal, state and local codes.
Do not look at an electric arc or thermal spray stream with unprotected
Wear safety glasses with UV protective side shields in addition to a proper
welding helmet with filter plate. Choose glasses, helmet and filter plate
according to ANSI Z87.1.
Protect exposed skin with adequate gloves and clothing according to ANSI
Remove combustible materials within 35 feet of working area.
Do not weld, braze, solder or thermal spray in presence of flammable
vapors or on a container that has held flammable or unknown materials.
Keep a charged fire extinguisher nearby, and know how to use it.
It is possible that the Threshold Limit Values (TLV’s) of some of the ingredients
and/or by-products formed during the normal use of some products and/or
equipment, will be exceeded without exceeding the TLV for general welding fume,
some of these may be carcinogenic according to some agencies.
Use engineering controls and personal protective equipment to keep exposure as
far below the TLV as possible.
If you are unsure of ventilation or adequate protection, contact your supervisor
before proceeding.
Due to the fact that Eutectic Corporation has no control over how, or where, our products and
equipment are used, or whether they are used according to our instructions, we recommend that
employers consider implementing into their safety practices the following, as a general guideline,
to promote workplace safety as it relates to the products and processes used for brazing, soldering,
welding, heating, cutting, gouging, thermal spraying, sealing and machining or grinding:
If at anytime you experience--difficulty breathing, seeing, or hearing; dizziness, eye
or skin irritation, or nausea:
Stop welding, brazing, soldering, or thermal spraying, etc. or remove
yourself from the area then…
Check all protective equipment and engineering controls and…
Inform your supervisor.
Do not resume the operation until a cause is determined and corrected.
Oxy-Fuel Thermal Spraying
Hazardous Decomposition or By Products: Fumes, gases and dusts given off during heating and thermal
spraying of metallic parts cannot be classified simply. The composition and quantity of these are
dependent upon the type of torch used, the powder spray rate, geometry of the part and upon the operator
maintaining the correct spray distance from the work piece. Other conditions which also influence the
composition and quantity of the fumes, gases, and dusts that workers may be exposed to include; the
number of workers and the volume of the work space; the quality and amount of ventilation; the position of
the worker’s head with respect to the fumes generated; the presence of contaminants in the atmosphere
(such as chlorinated hydrocarbon vapors from cleaning and degreasing activities).
During thermal spray processes, the fume and gas decomposition products generated are different in
percent and form from the ingredients listed in Section 2. Decomposition products of normal operation
include those originating from the volatilization, reaction or oxidation of the materials shown in Section 2,
plus those of any atmospheric vapors, gases or dusts that may be present at the time.
Reasonably expected constituents of the fumes gases and dusts produced may include: complex metallic
oxide dust, gaseous reaction products including combustion of ambient atmospheric contaminants,
carbon monoxide, carbon dioxide and condensing metallic vapors of the ingredients listed in Section 2.
One recommended way to determine the composition and quantity of fumes and gases to which workers
are exposed is to take an air sample in the worker’s breathing zone. See ANSI/AWS F1.1 and AWS F1.3
“Evaluating Contaminants in the Welding Environment – A Sampling Strategy Guide” which gives
additional advice on sampling. Both publications are available from the American Welding Society, P.O.
Box 351040, Miami, FL 33135.
Route(s) of Entry: Primary route is inhalation of fumes, gases and dusts given off during heating and
thermal spray process, the cutting and grinding of thermal spray coatings, and inhalation of dust during
powder handling operations. Skin contact, eye contact, and ingestion are possible when fumes condense
and dust is present. Skin and eyes must be protected from the radiation spectrum present during thermal
spraying. The fumes associated with heating and welding or the cutting and grinding of welded metal can
be dangerous to your health and overexposure can cause damage to nervous system, lungs and/or other
organs, thermal spraying may produce similar effects. Use adequate ventilation to keep below exposure
limits. Keep fumes and gases from breathing zone. Keep the workers head out of the fumes. The ACGIH
recommended general limit for Welding Fume and nuisance dust, not otherwise classified is 5 mg/m and
10 mg/m respectively. Thermal spraying may produce similar fumes. The threshold limit value for some
ingredients could be exceeded without exceeding the threshold limit value for general welding fume. Metal
fume fever, eye damage, burns, and allergic reactions are significant hazards during thermal spraying.
Aggravation of preexisting respiratory conditions may occur in some workers. Appropriate personal
protective equipment must be used.
Recommended Reading:
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