Pump repair with WEICON 2-component epoxy resin systems
Pumps used in industrial applications are exposed to a wide range of demanding operating conditions. These include abrasion caused by fluids containing solid particles and corrosion resulting from chemically aggressive substances. Other challenges are cavitation, erosion and mechanical wear, which can affect casings, impellers and internal functional surfaces.
WEICON 2-component epoxy resin systems provide a targeted and cost-effective solution for repairing damaged components. With these systems, worn surfaces can be restored and reliably protected against wear and corrosion in the long term thanks to highly durable coatings. As a result, the pump’s original functionality, operational reliability and service life can be significantly improved. At the same time, maintenance intervals can be extended and unplanned downtime reduced.
Typical types of pump damage
In industry, the following types of pump damage occur most frequently:
Worn or eroded internal surfaces
Cavitation and corrosion damage
Damaged casing geometry
Material loss on cast and metal surfaces
Wear on surfaces in contact with fluids
Uneven surfaces causing flow inefficiencies
Such damage can be repaired using a systematic approach: surfaces are prepared, defects are filled, contours are restored and then protected with wear-resistant top coats.
Pump coating for demanding repairs
Especially ceramic-filled epoxy resin coatings are characterised by high hardness and excellent wear resistance. They provide reliable protection against abrasive and corrosive influences. Their smooth, flow-optimised surface helps improve hydraulic efficiency within the pump system. In addition, reduced friction losses can deliver potential energy savings.
These epoxy systems are suitable for pumps used in applications subject to high mechanical and chemical stress, such as wastewater engineering, chemical processing, mining and the oil and gas industry. They can be used with various pump types, including centrifugal pumps, diaphragm pumps and gear pumps. They are particularly relevant in applications involving abrasive fluids, corrosive environments, solids content or sand-water mixtures.
Advantages of pump repairs using WEICON coating systems
1. Minimisation of downtime and rapid recommissioning of pumps
For pumps in critical industrial processes, ceramic-filled repair and coating systems enable the fast restoration of worn or corroded components. Thanks to short processing and curing times, maintenance windows can be reduced, unplanned downtime minimised and system availability increased.
2. Reduction of maintenance and lifecycle costs
Repairing pump casings, impellers, wear rings, diffusers and other pump-specific components is often more economical than replacing them. By restoring surfaces and fits and providing preventive protection against further wear, service life can be extended and the pump’s lifecycle costs sustainably reduced.
3. Enhanced wear and corrosion protection
Pumps are often exposed to abrasive solids, cavitation, erosion and corrosive fluids. Ceramic-reinforced coatings form a highly durable protective layer with excellent abrasion and erosion resistance. At the same time, the coating protects metal surfaces against corrosion and chemical attack from acidic, alkaline or other aggressive pumped fluids.
4. Improved hydraulic efficiency
The coating forms a smooth, flow-optimised surface in fluid-contact areas of the pump. This reduces surface roughness, flow losses and turbulence. As a result, hydraulic efficiency can be improved, flow rate increased and energy consumption reduced. In addition, restoring the original geometry of worn components helps compensate for performance losses.
5. Protection against cavitation, erosion and chemical stress
Cavitation damage is one of the most common causes of performance loss and premature wear in pumps. Ceramic coating systems increase surface resistance to cavitation erosion, erosive wear and chemical attack. This improves operational reliability and extends the service life of critical pump components.
6. High temperature and chemical resistance
In many industrial applications, pumps handle fluids at elevated temperatures or under chemically demanding conditions. Ceramic-filled coatings are characterised by high thermal stability and excellent resistance to a wide range of chemicals. This makes them suitable for protecting pumps in the chemical industry, water management, power generation and mining and process applications.
Typical pump repair and coating process
1. Surface preparation – the foundation for a durable coating
The quality of surface preparation is the decisive factor for the long-term performance and adhesion of the coating system. This is particularly important for pump casings, impellers, diffusers and other fluid-contact components, where surfaces must be carefully prepared.
Old coatings, corrosion, deposits and other contaminants should first be removed from the substrate. The surface is then blasted to the required cleanliness level (recommended: Sa 2½ according to ISO 8501-1) to achieve an appropriate surface profile for the mechanical anchoring of the coating system.
After blasting, the surface must be thoroughly cleaned, for example using WEICON Cleaner Spray S, to completely remove dust, oils, greases and other residues.
It is especially important to check for surface contamination by water-soluble salts. In pumps used in cooling water, seawater, mining, desalination or wastewater applications, chlorides, sulphates and nitrates can remain on the surface, leading to premature loss of adhesion or underfilm corrosion. It is therefore recommended to carry out a Bresle test in accordance with ISO 8502-6 and ISO 8502-9 prior to coating to determine the salt contamination level of the surface. If the permissible limits are exceeded, additional surface cleaning is required. A properly prepared surface is essential for a durable and reliable repair and coating.
2. Damage repair and restoration of the original pump geometry
NAfter surface preparation, existing damage such as cavitation erosion, corrosion attack, spalling, pitting, erosion damage or mechanical damage is repaired. Depending on the damage pattern and operating conditions, different WEICON repair systems are used:
- WEICON HB 300 for re-profiling, levelling and rebuilding worn surfaces
- WEICON A for filling larger defects, spalling and corrosion damage
- WEICON WR2 for restoring highly stressed areas subject to severe abrasion and erosion
3. Grinding and fine profiling
After the repair materials have cured, the rebuilt areas are mechanically machined and adjusted to match the original component geometry. Special attention is paid to:
- flow surfaces within the pump casing
- impeller blade profiles
- inlet and outlet areas
- diffusers and guide vanes
Precise surface finishing reduces flow losses, turbulence and local eddies and creates optimal conditions for the subsequent wear protection coating.
4. Final coating for wear, corrosion and cavitation protection
After completion of the repair work, the entire fluid-contact surface is coated with a ceramic-reinforced protective coating.
The following systems are especially suitable:
- WEICON Ceramic BL for protection against corrosion, cavitation and moderate abrasion
- WEICON Ceramic HC 220 for applications with extreme abrasion and erosion wear, for example in mining, slurry, sand, ore, ash or cement conveying applications
The coating forms a highly dense protective barrier against corrosion and chemical attack as well as a resistant surface against cavitation, erosion and abrasion. At the same time, the smooth surface structure supports the hydraulic efficiency of the pump.
5. Multilayer system with visual wear monitoring
For pump applications with particularly high levels of abrasion and wear, a multi-layer coating system can be used. In this approach, an additional layer of WEICON GL-S is applied between the repair layer and the top coat. By using different colour shades, a visual wear indicator system is created.
During operation, maintenance teams can quickly assess the condition of the coating. As soon as the underlying contrast layer becomes visible, timely maintenance can be planned before damage to the base material or pump geometry occurs.
This improves planning reliability, reduces unplanned downtime and supports condition-based maintenance of pump systems.
WEICON products for pump coatings
WEICON
HB 300
For rebuilding defects, levelling uneven surfaces and repairing cavitation and corrosion damage. HB 300 is used in many pump repairs as a key build-up material.
WEICON
Ceramic BL
For wear-resistant top coats on internal pump surfaces and repaired components. For applications requiring abrasion resistance, chemical resistance and long service life.
WEICON
Ceramic HC 220
For pumps subject to very high stress and extreme abrasion. It is used, for example, in wastewater treatment and in jet pumps for sand backfilling applications.
WEICON
GL / GL-S
For wear-resistant top coats and multilayer coating systems with a visual wear indication system. The contrasting colour layers help identify wear.
WEICON
WR2
For restoring contours prior to the top coat, particularly in applications involving sand-water mixtures and severe wear.
WEICON
A
For levelling larger damage on heavily eroded pump components, such as damaged cast iron.
Industrial pump repairs from around the world
The following applications show how pumps have been repaired and protective coatings applied using WEICON products. This includes surface preparation, rebuilding of damaged areas and the final coating for protection against wear, corrosion and further stress.
Assess pump damage. Select repair system. Minimise downtime.
Do you wish to know which WEICON 2-component epoxy resin system is suitable for your pumps, their operating loads and damage condition?
We support you in selecting a technically and economically sound repair solution.
Frequently asked questions about pump repairs
Which types of damage can be repaired on pumps?
Typical damage includes cavitation, corrosion, erosion, material loss, damaged contours and uneven internal surfaces. These can be prepared, rebuilt and subsequently protected with wear-resistant coatings.
Why are ceramic-filled epoxy resin coatings valuable for pumps?
They improve abrasion resistance, provide protection against corrosion and chemicals, reduce friction and turbulence and extend the service life of highly stressed pump components.
Is it worth repairing a pump instead of replacing it?
In many applications, yes, especially when function, geometry and surface protection can be restored using a coordinated system. Key advantages include lower costs, reduced downtime, longer service life and the avoidance of a new purchase.
How does a pump repair process work?
In general, the repair begins with surface preparation, typically by abrasive blasting followed by cleaning with WEICON Cleaner Spray S. Damaged areas are then rebuilt or levelled, for example using WEICON HB 300, WEICON A or WEICON WR2. Depending on the requirements, this is followed by a multilayer coating system with WEICON GL / GL-S as a control layer and a final coating using WEICON Ceramic BL or WEICON Ceramic HC 220. This approach allows the function, protective properties and service life of the pump to be restored or improved.
Which materials are suitable for pump coatings?
A pump coating with WEICON epoxy resin systems is suitable for metals such as steel, stainless steel, aluminium, brass and bronze. It reliably protects pump casings, impellers and similar components against wear, corrosion and chemical attack.
How long does a pump coating last?
When properly applied, a WEICON pump coating typically lasts several years. The exact service life depends on the process fluid, temperature and mechanical and chemical stress.
