The use of underwater curing epoxies were the most practical solution for this project. In the complete refurbishment of the underside of this floating structure some areas were replaced. Others areas required repairs to be done in-situ by using underwater curing epoxies. A team of experienced divers applied the underwater curing epoxy coating.
Chemcote’s surface tolerant Epo chem™ system is able to provide full coverage to surfaces where ideal surface preparation cannot be achieved
Condition after application of 2nd coat
Repairs were carried out at low tide where possible. Fresh water washing sections provide suitable surface preparation before applying the underwater curing epoxies.
Removal of large, flaking corroded areas and coating back to bare steel by mechanical preparation using pneumatic needle gun, air chisel, scabbling and bristle blaster
Preparation underwater to St 2 by using an underwater grinder Primer applied to create a continuous coating without pinholes wearing gloves and application mitts.
Product was lathered on in small, workable sections and cured overnight
The next day at low tide, the repair area above the surface was washed with fresh water, then RA 500M, glass flake filled topcoat was applied to above and below water sections
By coating with Epo chem™, follow up inspections indicate the coating and repairs are still in good condition, and is expected to exceed 10 years life in service
Environment Mildly acidic
water ranging between 50-70°C
Challenge It was too late for some areas requiring
replacement and repair of wall plate and internal pedestals supporting the
rolls requiring replacement. Removal of the tank wasn’t feasible and an insitu
cost effective repair method was required. With live crane rails, great heights
and the centre of an active production area to contend with Chemcote came to
Chemcote’s Solution Prefabricated items to be coated before installation to reduce application time on site to particularly on difficult to reach areas
of heavy corrosion and scale by needle gunning, scabbling and chiselling exposed
the condition of the substrate beneath all of the scale and build up, locating
holes through the plate and very thin areas requiring unplanned fabrication
supports and a weir plate were welded into place, in addition to penetrated
weld seams allowing moisture to permeate. Abrasive blast was carried out to
repair techniques and pit filling were used to achieve structural integrity on
of RB300 Series to a nominal thickness of 400µm total DFT
testing at 12kV was carried out
Results By coating with Chem-tect™ RB 300 will provide an excellent corrosion
barrier, expected to exceed 20 years life in service
Existing epoxy lining on this chemical storage tank was in poor condition, with large sections experiencing deterioration alongside staining and corrosion of the tank wall. This stained the finish product preventing use until a long term solution was found.
Set up scaffolding inside tank and utilised efficient surface preparation techniques to minimise mobilisation of blasting costs whilst still achieving an optimal surface to produce long term coating adhesion
Mobilise to site and set up extraction Abrasive blast to AS 1627.4 2005 Class 2.5, 60μm profile Application of 1 coat of Epo-Chem RS 500P to a nominal thickness of 100μm Application of 1 coat of Epo-Chem RA 500M to a nominal DFT of 350μm Sand flanges and finish off internals Carry out internal QA, DFT check
By coating with the Epo-Chem™ system Chemcote restored the chemical storage tank back to service, with long term peace of mind offered to the customer
Strainer has been in service for 30 + years. Inspection of the strainer body, back wash covers & critical dimensions found the substrate to be severely corroded, illustrated by the extent of graphitised iron, holes through the casting and diminishing wall thickness
Composite materials were chosen to rebuild the metal loss. We then applied RB 364 series , a glass flake filled vinyl ester consolidated with composite reinforcing to return the casing to its original strength
holes using backing rod
blast and treat to reduce metallic salts by hot washing and re-abrasive blast.
RB 364 in two coats where
required to obtain minimum thickness of 1,000μm
reduce the sharp edges and pit depth allowing a smooth uniform coating to be
QA included spark
testing and DFT to confirm coating integrity
Apply coat of RL 500 PF to externals
After 15 years of Chemcote Coatings providing long term protection on other strainers and their backwash covers within the power station, Chemcote was enlisted for repairs to the 2 large Strainers to one of the main condenser units
A core drilling process and testing procedure was undertaken to analyse the extent of the Ammonia Sulphate ingress before planning a work method to avoid contamination from other work happening on site
Chem-tect™ Vinyl Ester system is filled with screened glassflake technology for long lasting protection from aggressive chemicals such as sulphuric acid, abrasion and high temperature environments
The lining was cut and removed by sections to allow the plant to continue operations.
The required surface preparation was undertaken to remove laitance from the concrete surface
Where repairs to the concrete were needed, the area was broken up with a Jackhammer
Crushed rock was placed in void and compactor was used to level fill
Steel Reinforcement was placed
Treatment with Vinyl Ester Primer to seal the porous surface
Core drilling samples taken to assess
extent of concrete damage
Pour fast setting Polymer Concrete was into position with an air powered hammer chisel to stabilize the ground
Trowel off and cure
Promote second coat on site for fast reaction
Top with Garnet to provide anti slip properties
Chemco International’s Chem-tect™ system has provided years of maintenance-free service and excellent chemical resistance. These materials are substantially stronger than the original slab and will protect the slab in the future against mechanical damage and further sulphuric acid ingress
Asset owners of the Extension Leveller Cassette engaged us to inspect and
nominate a complete coating solution
where standard paint systems failed to
prevent surface deterioration resulting in
large refurbishment costs
RL 500PF is a surface / wet tolerant zinc rich
epoxy, required to a uniform thickness for
Grind sharp edges and weld porosity.
Abrasive blast to AS 1627.4 Class 3, 75µm profile
Application of RL 500PF with nominate thickness 300 microns
Application of 1 coat of RC 500GTC to a final DFT of 400µm
Since re-coating was carried out by Chemcote, the extension leveller has been found to be in excellent condition and maintenance costs have been dramatically reduced
Water Box – Steel recently coated using ceramic filled epoxy
Epo-Chem™ RS500P and RA500M glass flake filled epoxy
Pressure vessel containing clean brackish water at ambient temp
Carry out composite repair (rated to 1200psi) to hole through including ongoing repairs during short outages to failing ceramic lining.
RS 500P is a surface and wet tolerant Mio Epoxy primer designed for application on surfaces where high humidity is a concern. Due to its shorter cure time it was also used to laminate the damaged area (internally and externally) to enable rapid return of water box to service.
Needle gun and bristle blast internal and externals of the affected area, spot blast 100mm of coating outside of the repair area.
Carry out composite repairs to Chemcote’s specifications using RS500P.
Application of top coat Epo-Chem RA500M to a nominal WFT of 250-300µm.
Continuous repairs are required after relining in 2015 using a ceramic filled epoxy was found to have localised failures within 3 months of installation. All repairs carried out by Chemcote have been found to be in excellent condition.
Epo-Chem™ RS500P a wet and surface tolerant epoxy primer containing 100% solids and RA500M a wet tolerant, glass flake filled epoxy containing 100% solids. Both products are capable of being applied in high humidity including under water.
Salt water strainer
Repeat abrasive blasting and hot washing to reduce metallic salts below 25 ppm. Pit filling of deep metal loss and composite reinforcement where required.
Repeat abrasive blasting and hot washing of basket strainer to reduce metallic salts below 25 ppm. Pit filling of deep metal loss and composite reinforcement where required.
High pressure hot wash and repeat abrasive blast to reduce soluble salt levels below 25ppm
Abrasive blast to AS 1627.4 Class 2.5, nominal 75µm profile.
Application of RS500P, then two coats of RA500M Series to obtain minimum thickness of 500µm
Cast sealing ring for O ring groove rebuilding the original surface profile using RA500M
Carry out QA, spark test at 4kV and DFT to confirm coating integrity.
Quick turn-around allowing minimal disruption to meet project milestone targets.
Strict QA requirements including DFT and holiday testing to the required voltage to ensure many years of high performance
Epo-Chem™ RP 500 series, a moisture tolerant ceramic filled epoxy top coat, providing excellent long term cavitation resistance.
15°C – 30°C sea water
The 10-year-old valve experiencing cavitation damage with replacement unavailable within a reasonable time frame. Quick turnaround for return to service required.
Protect critical surfaces by masking and abrasive blast areas to be repaired.
Weld new gussets to provide mechanical strength where lost.
Application of Epo-Chem™ RS 500P to a nominal thickness of 100µm, rebuild original profile height using InD-cote™ and top coat using Epo- Chem™ RP 500 with a nominal DFT of 350µm
Valve parts are not available from the OEM and a replacement was going to cost an estimated $120K. The repairs have effectively saved the asset owner considerable time and money in full valve replacement. The refurbished paddle is now reinforced using Kevlar and expected to provide more than 10 years of additional service life. For more information please feel free to contact Chemco on 1300 CHEMCO (243 626).
Chem-tect™ RB 300 series, a glass flake filled vinyl ester, provides excellent permeation resistance and high dielectric strength.
40-60°C, sea water
To provide a long term solution for the corroded tube ports and tube sheet.
Tube internals were protected by inserting specially ordered silicon plugs to prevent abrasive blasting from damaging wall thickness. Abrasive blast as per required standard and remove silicon plugs and glue nylon tube inserts into position and then pitfill all deep cavities using RB 300 Series. We used the proprietary method to obtain a flat surface using RB 300 Series.
An estimated replacement cost was in the range of $500K and this refurbishment is expected to extend the life for another 20 years. Chemco is available for all corrosion related issues with nearby ancillary equipment. For more information please feel free to contact Chemco on 1300 CHEMCO (243 626).
Critical overhead pipe support structure outside turbine hall
Epo-Chem RS 500P a wet and surface tolerant mio epoxy primer and Epo-Chem RA 500 series, a moisture tolerant glass flake filled epoxy top coat, providing excellent long term corrosion resistance.
15°C – 60°C sea water
The original environment was considered atmospheric, due to regular leaking valves and flanges the coating specification was necessary to be reclassified to immersed after the original paint system failed.
Access difficulties and age were all a consideration as part of the assessment process. Abrasive blasting was not possible as the containment and clean up costs we’re prohibitive.
Mobilise to site
Ultra high pressure water blast up to 20,000 psi using our small foot print machine after a quick mechanical clean in the difficult to reach areas. Carry out soluble salts test to ensure the levels are within the coatings parameters.
Application of Epo-Chem RS 500P to a nominal thickness of 100µm and top coat using Epo-Chem RA 500 with a nominal DFT of 350µm
Saved hundreds of thousands of dollars in replacement costs and the asset owner is rest-assured that Chemco will provide long term corrosion protection, evident through the years of applications around the power station.
Nickel Laterite mine operating at 100°C. Vessel is required to contain and hold Sulphuric Acid Slurry as part of the leaching process.
Internals had previously been coated with a widely accepted epoxy which failed within months causing the substrate to corrode. Pitting was experienced and protection against long term exposure to acid was required.
Externals needed protection from acid rain and atmospheric corrosion, also needing a durable hard-wearing finish.
Achieving adequate adhesion to Super Duplex is a challenge for every coating, RC364 was selected for its adhesion to exotic materials.
RB 300 provides excellent corrosion resistance, creating an impermeable barrier between the process environment and substrate.
Abrasive blast with Aluminium Oxide to class SA 2.5 90μm surface profile.
Apply RC364 to a DFT of 400μm on internals and externals
Apply RB364CS to a total DFT of 1mm on internals
Apply RB300TC to the total DFT of 400μm externally
After a year the tank is still in excellent condition, the client has requested the same treatment on other vessels within the site.
Coating selection, approvals and application was performed by CCS – Distributor Agent of Chemco International in Western Australia.
304 Stainless Steel – Ammonia absorber and circulation tank.
Chem-tect™ RF364 – vinyl ester / acrylic co-polymer enhanced with flaked glass; very suitable for immersed environments where superior resistance to chemical attack is required.
Normal operating temperature is 60-70°C. Excursions up to 100°C are common.
• Wet ammonia gas
• Diluted sulphuric acid (up to about 20%)
• Ammonium sulphate
• Aromatic and aliphatic hydrocarbons
• Hydrogen sulphide
• Hydrogen cyanide
Prevent Stress Corrosion Pitting in the heat effected areas, these are generally found either side at the toe of the weld. Apply corrosion protection on the entire internal surfaces within a 72 hours outage.
Abrasive blast to Chemcote’s Specifications and 3 coats of Chem-tect™ RF 300 Series.
Recommend the entire internal surfaces are treated.
Mobilise on site.
Set up of dust containment only.
Set up of De-humidification equipment.
Abrasive blast to Chemco Standards.
Application of a Chem-tect™ RF 300 in 3 coats including strip coat all difficult to reach areas.
De-mobilise from site.
The best outcome the asset owner has obtained after years of trials using various epoxies and fibreglass linings. The combined large anchor profile achieved while abrasive blasting and excellent permeation resistance of the glass flake filler has proven itself again.
The pump had dropped off in efficiency due to the combination of corrosion erosion and mechanical fatigue. This was due to a poorly specified and applied coating which was delaminating allowing corrosion to exist.
After 8 years in service the substrate was corroded and heavily contaminated with metallic salts. Treatment using a combination of methods including abrasive blasting, hot washing and acid washing to reduce salts below 25ppm. We then recommended the application of 2 coats of Chem-tect™ RB 364; a glass flake filled vinyl ester providing an excellent corrosion barrier and long term protection. We then applied 2 coats of Epo-chem™ RP 500 to enhance fluid efficiency in turn reducing power consumption.
Strip and assess
Manufacture template to ensure mating faces match
Grind chamfer on all flanged faces, allowing the coating to be applied on the flange face preventing future crevice corrosion.
Protect critical dimensions
Abrasive blast and treat to reduce metallic salts by hot washing and re-abrasive blast.
Apply corrosion barrier Chem-tect™ RB 364
QA included spark testing and DFT
Apply topcoat of Epo-chem™ RP 500
By coating with Chem-tect™ RB 300 & Epo-chem™ RP 500, future corrosion erosion is prevented with a reduced amount of friction through composite technology. The pump now functions more efficiently when in use consuming less power, which led to carbon credits and a reduction of greenhouse gas emissions. The payback period of the entire refurbishment worked out to be only 14 months.
The lagging was removed to extend the life of the shell externals. While the vessel was in service, surface preparation and corrosion application were undertaken. Surface temperatures were ranging between -5°C to around +25°C. This causes the substrate to sweat heavily during coating application.
Wet & Rust Tolerant Epo-chem™ RL 500PF was recommended for this application to prevent CUI (corrosion under insulation). This system requires minimum surface preparation (i.e. no need for dry grit blasting). Rain, water, condensation or high humidity have no effect on freshly painted surfaces.
In this case, abrasive blasting was possible and coating was applied to an average DFT of 300µm total, achieved in two coats.
This is a prime example of innovative technology being used to save the Clients existing plant from the possibility of failure. The protective coating was able to provide a vast improvement in plant safety and also exceeded the engineer’s expectations, to the point that Chemco’s Epo-chem™ RL 500PF is now specified on all similar applications within this site.
Epo-chem™ RL 500PF is designed to provide corrosion protection for applications of up to 150°C and also is designed for application on new and aged galvanised steel, making it ideal for electricity pylons, exhaust stacks and CUI applications.
System applied within the past 18 months was not FDA approved and tainted 1,000’s of litres of wine. Removal of existing delaminating coating system and to provide a sound coating solution system to prevent future leaks and tainting of final product.
We recommended priming with RH 800, a moisture tolerant damp concrete primer, followed by RI 800 for the deep pitted areas and any joins that require filling. Top coated using RB 500 and chopped strand mat to prevent coating from cracking when the precast pieces of concrete move. This system has an extremely fast turnaround and cure time.
The benefits include no odour during application and is approved for wine and beer tank applications.
Remove existing lining of the wine tank by destructive methods and abrasive blasting to provide a surface profile. Application of coatings as above, allow to cure for 3 days prior to return to service.
A long term leak free internal composite surface designed for beer and wine applications approved by the FDA.
Highly corrosive range of chemicals including Sodium Hydroxide and Hydrochloric Acid.
Upon inspection, the concrete bund was identified to be in a poor condition. This is due to the existing surface deteriorating after years of exposure. There are many locations on the bund that show a degree of damage and there is also evidence of chemical pooling. This seems to indicate that the fall is not functioning properly and, therefore, needs to be addressed and reinstated.
To ensure that the maximum life of the coating is achieved for our client, we reviewed the environment conditions, and we are specifying the Chemco International Glass Flake Filled Chem-tect™ 300 series coatings. These coatings have been chosen as they offer excellent chemical and corrosion protection.
This coating project was completed on time, to budget and an inspection after 2 years has been recommended. Our Client was pleased with the result and the service.
1,000°C Coking Coal transport wagon where 80°C recirculated water is used to quench the load.
After successful spot repairs on existing hot car structures insitu, we were asked to provide the same solution on a brand new fabrication. The project consisted of a long wall approximately 20 mt long and 2 side walls approximately 4 metres long each. This was an excellent opportunity for Chemco to provide ultimate surface preparation and application. The challenge was the length and weight of the items and the attention to detail required around all the crevices and welds.
We recommended Epo-chem™ RE 500P a high temperature resistant surface tolerant, Novolac Epoxy primer. Top coated with Epo-chem™ RW500, glassflake filled, high temperature resistant Novolac Epoxy. The coating system provides excellent corrosion/erosion resistance against this environment.
Abrasive blasting to AS 1627.4 Class 3, 60µm profile.
Application of RE 500P in one coat at 100µm nominal and application of RW 500 at 350µm Dry Film Thickness (DFT)
Most linings were breaking down and failing within a short period of time, between 2 & 8 weeks of service. An inspection of our spot repairs after 12 months have indicated that our glass flake coating system can withstand these harsh environments. We expect the freshly coated components to provide the most superior coating system used on this structure to date. This saves the client a lot of money and reduces a lot of equipment down time.
Epo-chem™ RL 500PF – a surface/moisture tolerant zinc rich epoxy coating resistant to 150°C which can also be applied on hot surfaces.
Quenching station – Steam with radiating heat at 130°C
These segments are subjected to extreme conditions as part of the steel casting process. Upon inspection, we found severe paint breakdown and asset deterioration. This was due to previously applied coatings incapable of resisting the high temperatures. Premature corrosion was also found during inspection.
We recommended 2 coats of Epo-chem™ RL 500PF. This coating system is known to provide excellent long term corrosion resistance for this type of environment.
The client welcomed a trial in an effort to reduce long term maintenance costs. He found this was possible using the Chemco anti corrosion coating system. After equivalent time in service our zinc rich high temperature resistant epoxy coating system was showing no signs of failure whatsoever. A long term corrosion protection was achieved. All segments are now specified with this Chemco system
This project presented two challenges to our team. The first challenge was coming up with a coating system that would adhere well to galvanised steel. The second challenge was making sure that this system would also be suitable for the very aggressive coastal environment.
Epo-chem™ RL 500PF is a surface and moisture tolerant epoxy that is well suited to this environment as it has superior adhesion to new or aged galvanised surfaces. Firstly, we prepared the surface ready for the application of the primer. Our team then applied 2 coats of Epo-chem™ RL 500PF. To ensure no moisture could form in the crevices we sealed all cracks and crevices using a polyurethane sealant. The fascia was finished off with a polyurethane finish coat in black.
After extensive surface preparation and surface rectification we were able to apply the best protective coating solution for this environment.
The project was a series of pipe spools with diverse configurations and diameters. These items required long term corrosion protection against high temperature salt water. This would be classified as an extremely corrosive environment. For this reason they demanded a superior coating system. The complex schematics and pipe diameters made it challenging to coat internally. Field fitting of flanges was required to ensure the completed spools lined up.
Chemcote’s solution was to apply Chem-tect™ RB 300 series to the internals of the pipework. This coating is a glassflake filled vinyl ester. Glassflake filled coatings have proven to be the most suitable where good corrosion resistance and excellent mechanical properties are required.
Internal Corrosion Protection
We started by grinding welds and sharp edges prior to abrasive blasting.
We then abrasive blasted to class AS 1627.4 – Class SA 3.0.
The majority of work was conducted in our purpose built workshop. The finishing touches were carried out onsite once the field fitted flanges were complete. The asset owner was extremely pleased with the quality, turnaround time and communication throughout this project. The coating will exceed the life requirements of 25 years and reduce maintenance costs in the future.
8 Year Old – Mild Steel water boxes & Stainless Steel tube sheets
Chem-tect™ RB 300 series, a glass flake filled vinyl ester, provides excellent permeation resistance and high dielectric strength.
40-60°C, brackish / sea water
New tubes were installed in the condenser tube sheet made from an exotic Stainless Steel compared to the low grade tube sheet. We were asked to provide a solution with a coating with a high dielectric strength to prevent the galvanic reaction between dissimilar materials.
Tube internals were protected by inserting specially designed plastic caps on Inlet/Outlet and Return side of Water Box. This protected the condenser tube sheet.
The entire face was hot washed to remove any lubricants and other potential contaminants before abrasive blasted to ensure surface is clean and the correct surface profile is obtained. RB 300 was applied to tube-sheet face, followed by some other areas considered critical, such as the baffle plates where the existing coating has failed due to under specification. Carry out high voltage spark test beyond Australian Standards to ensure coating integrity.
The extended life of the coating is expected to exceed 20 years in service, the plant owner is requesting Chemco to assist further with other corrosion related issues with nearby ancillary equipment.