Why overlook 30 Years of Steel Corrosion Mitigation Field Performance proof in action?
Performance Review: Gusset Plate Overcoat Coating Repair
– Tub Girder Bridge (Lat: 49.950360, Long: – 97.097123)
BACKROUND: 3 coat system (ZEU) installed on tub girder superstructure in 1992.
Inspectors discovered that the applied ZEU coating was failing on the sharp gusset plate corners and rivet heads.
Chemically active HRCSA was used to overcoat the tub girder connector plates in 1993 . (Colors matched at time of application).
Tub Girder Bridge
Tub connector plates overcoated with HRCSA in 1993.
Latitude: 49.950360,
Longitude: -97.097123)
Climate: -35C to 35C +
Overhead crane used to pressure wash (SSPC SP-WJ4) for HRCSA gusset plate preservation overcoating.
ZEU 1992-2023
Zinc-epoxy-urethane applied on flat surfaces heavily oxidized and quickly eroding.
HRCSA 1993-2023
HRCSA self-priming topcoat applied onto gusset plates still intact.
Color and UV protection also intact.
ZEU July, 2024
Oxidized, eroded with steel corrosion on the steel substrate.
HRCSA, July 2024
Coating still intact.
* Field studies suggest that HRCSA self-priming topcoat applications erode at a rate of ~1 ml every 5-6 years.
Japanese laboratory studies predict field performance of more than 45 years service with a 10 mls dft HRCSA self-priming topcoat application.
HRCSA: THIRTY ONE YEARS IN SERVICE AND COUNTING.
The climate where this bridge is located can be extreme. Additionally, road salts are regularly applied to de-ice roads. Both are challenging environment conditions for any coating system – especially for overcoat systems applied overtop already in place paint systems.
HRCSA can applied overtop almost all tightly adhered, contaminant free, coatings on flexible steel structures, galvanized steel, metallizing, zinc primer, A588 weathering steel, wrought iron, stainless steel and aluminum. (See data sheets).
HRCSA is a chemically active, elastomeric coating system that exerts low surface energy adherence on the substrate.
When FHWA laboratory tests were released in 2011, it was hard to believe that HRCSA would outperform multi-coat, sacrificial zinc coating systems – but it did (see graph below).
Other preservation situations where HRCSA provides superior corrosion protection.
HRCSA on Moving Parts (Bearings, Pin Connectors, Fasteners, Connection Plates, etc.).
Bearings: Bearings move to accommodate expansion and contraction, and their connections are vulnerable to premature coating failure – but not with HRCSA self-priming topcoat with HRCSA Penetrant applied inside the connection before coating.
HRCSA on Wire Rope
Wire rope moves – a lot. HRCSA is a excellent coating for maintaining wire rope because it does not leave a void between it and the wire rope strands. In fact, HRCSA Penetrant literally migrates inside the strands with it’s polar bonded calcium sulfonate platelets.
HRCSA on Pack Rusted Joints and Connections.
Packrust: When corrosion between plates takes hold, the only surface preparation method that can be used is high pressure water cleaning with salt remover additive to clear debris, non tightly adhered corrosion by-product and salts.
Once cleared, the capillary channels inside the corrosion byproduct is force air dried then pressure loaded with HRCSA low viscosity, 100% solids Penetrant to chemically stop the corrosion from continuing to build. Sealed with HRCSA self-priming topcoat, this “HRCSA meld coat” forms an elastomeric, chemically active seal that stops corrosion inside these connections for decades at a time. In the treated example below, the HRCSA treated pack-rusted connection was 17 years old at time of photography.
This truss bridge also in extreme climate environment. LAT: 53.530464, LONG: -113.510807 where contraction and expansion happens to be the bane of hard film form paints, but where HRCSA performs reliably and dependably.
SALT MITIGATION (Chlor*Rid, Termaclean, or equivalent.)
Whether abrasive blasting or water jetting, always mitigate non-visible contaminants on the substrate you are about to apply a coating system to. If dry blasting only, a wash with salt remover additive will be required. If high pressure water cleaning only, additive into the potable pressure wash water.
HRCSA Application Steps
Step 1: High pressure water clean (35 MPA / hot water / rotating tip) to remove loose paint, non tightly adhered rust and other contaminants. Included salt remover additive [Chlor*Rid, Termaclean, or equivalent) to mitigate non-visible contaminants on the substrate.
Thoroughly clean and flush pack-rusted connections for full removal of all loose matter and corrosive elements. Apply clean, dry, high pressure air to remove all moisture from inside crevices.
Step 2: Pressure apply HRCSA Penetrant and flood all of the capillary channels inside opened connections and cleaned pack rusted areas. Apply to refusal the brush out the excess to avoid pooling.
Encapsulating the active HRCSA penetrant chemistry: Applying HRCSA topcoat onto the penetrant and brushing it into the connection to create a meld layer forms a permanent seal and protective barrier against the elements.
The End-Result: 30+ years of field proven performance. .
Case Study
“The most serious corrosion failures come from severe attacks within structure critical areas like Joints and Connections, Bearings, Pin Bearings, connection plates and between wire rope strands. The areas where hard film form coatings tend to microcrack and allow contaminated water in to form crevice corrosion and pack rust that tears apart structures from the inside-out.”
HRCSA is a chemically active steel corrosion maintenance system