The core of TMI Coatings’ work is to restore America’s infrastructure. Recently TMI won the opportunity to restore and recoat the clarifier and pipe system for the City of Temple, TX Water Treatment Plant. The clarifier is 100’ diameter with a depth range from 16’ at sidewalls to 20’ at the center—a large scale project involving both concrete and steel substrates. Because there were different substrate types and each substrate had different service environments there were numerous coating systems applied in this project. This required precision, organization, and expertise on the part of the TMI Coatings crew.
Before work began TMI Coatings completed a Job Hazard Analysis for the City of Temple. Some of the many items that were analyzed to ensure safety were the operation of heavy equipment, welding, sandblasting, and fire hazards. TMI Coatings completed numerous repairs in tandem with the new coating system. The clarifier is made of both steel and concrete substrates; parts of each of those substrates are in immersion service. For the steel areas of the clarifier, a multiple-coat system was applied.
- To ensure proper coating adhesion, the steel surfaces were first abrasive blasted to SSPC-SP 10 Near White Metal Blast. This coating standard removes dust, coating, and mill scale.
- Spent abrasive samples were sent to an off-site laboratory for analysis.
- In order to contain the blast media a temporary roof cover of cable support tarpaulin bonnet was constructed.
- Ventilation was also constructed by TMI Coatings to ensure a safe environment.
- TMI maintained continuous expulsion-proof ventilation during surface preparation, coating application, recoating, and curing.
- The prime coat applied to all the blasted steel of the clarifier was a zinc-rich aromatic urethane. This primer provides outstanding long-term corrosion resistance.
- All blasted areas were primed.
- A stripe coat of polyamidoamine epoxy was then applied to all weld seams, edges, corners, bolts, and pits. These areas are especially vulnerable to corrosion, so applying a stripe coat ensures extra protection. The polyamidoamine epoxy offers high-build edge protection.
- To the lower steel, a high solids polyamine epoxy was applied at 12-15 mils. This coating offers high-build edge protection and excellent corrosion resistance. It also provides excellent resistance to abrasion.
- To the upper steel, two additional layers of coating were applied. An intermediate coat and a finish coat of an aliphatic polyester polyurethane provided additional color retention and UV resistance. The finish coat is an extremely hard, chemical-resistant urethane coating with excellent resistance to abrasion.
- The concrete sections of the clarifier had extensive cracks with fear of water penetration. TMI Coatings repaired and sealed the concrete areas with water-resistant materials.
- The interior sections of concrete were abrasive blasted per SSPC-SP 13.
- All dust was washed away and cracks larger than 1/64” were routed out and filled. It’s important to rout out cracked and disbonded concrete to reach sound substrate for restoration.
- A waterproof cementitious crack filler was spray applied and then troweled into the substrate for proper coating adhesion.
- The additional exterior concrete sections that were not in immersion service were pressure washed with high-pressure washers with rotating tips.
- Two coats of a modified waterborne acrylate were applied to the cleaned substrate. This coating is flexible and breathable with excellent elastomeric protection in exterior exposure.
The second part of this large-scale project included repairing and recoating the extensively damaged Feed and Filtration ductile iron piping. The piping was heavily corroded; TMI replaced thousands of corroded bolts before even beginning the coating process.
- In order to enclose the pipework, TMI erected a full containment system around the piping including a negative air enclosure system for dust collection.
- The pipes, pipe supports, connections, and saddles were abrasive blasted to SSPC-SP 6 Commercial Blast with 1.5 mil profile.
- Two coats of polyamide epoxy were applied.
- Pipes exposed to the exterior elements received an additional topcoat of aliphatic acrylic polyurethane. This coating is highly resistant to abrasion, wet conditions, corrosive fumes, and exterior weathering.
- Holiday testing was performed on the steel substrates per SSPC PA2 standards. Holiday testing is a non-destructive way to test applied protective coatings for discontinuities such as pinholes and voids. This type of testing is used to find coating film discontinuities that are not readily visible so they can be addressed.
Restoring America’s infrastructure is a weighty goal for a coating contractor, but it is inspired by projects like this that require the specialty and skill of TMI Coatings. Each project like this is made possible by the skill and talent of TMI Coatings staff and crew members. TMI Coatings was recommended for additional work by the Project Engineer. TMI’s quality of work, cooperation with staff, cooperation with the public, and timely performance were all rated great!
With 35 years of experience, TMI Coatings will have your project completed on time and within budget. Contact us today atfor your free, no obligation quote.