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EonCoat CUI vs. Polymeric CUI Coating Systems for Insulated Tanks

Why Oil and Gas Companies Use EonCoat® on Insulated Tanks

CUI is the common term used for corrosion under insulation. Corrosion on insulated tanks is a threat to safety, productivity, and the bottom line. The right protective coating reduces the risk.

Let’s compare the EonCoat CUI Coating with Typical CUI Coatings. We compare them in 2 ways.

  1. Surface Preparation
  2. Coating Application


To prepare the surface for either coating system we need to grit blast, though if no old coating or mill scale is present, and rust has tightly adhered then EonCoat can be applied directly to the rust. The Typical polymeric CUI Coating system requires a near-white metal blast (SSPC 10) to properly adhere.

After blasting the coating needs to be applied immediately before flash rust occurs, or a surface treatment must be applied to hold the blast. If it were to rain before the application is complete the entire process would have to start all over again.

EonCoat CUI only needs a surface prep of NACE 3 / SSPC-SP 6. It can also be applied directly to surface rust and does not require you to hold the blast. EonCoat CUI Coating can be applied in any humidity, even rain if it is not directly on the substrate. Less Abrasive used to sandblast the surface, less blasting time & less clean-up time.

Steel Surface being grit blasted

Worker grit blasting a steel asset


For the Typical (usually polymeric) CUI Coating Systems you not only have to hold the blast. Multiple coats are required and generally long cure times. This translates to cost and downtime.

EonCoat CUI can be applied directly to surface rust and can be sprayed on. The application of the coating is quicker. EonCoat CUI is also a one-coat system that cures in under 15 minutes.

Fewer coats to apply, less time waiting for a cure. This leads to lower application costs and less downtime.

An insulated petrochemical storage tank being prepared for service

An insulated tank being prepared for service.


Before EonCoat CUI was available ordinary, generally polymeric, CUI Coating Systems were the only option. If you’ve used traditional liquid polymeric CUI coating systems, you are familiar with their major limitations, namely:

  • They require extensive surface preparation and lengthy downtime to apply.
  • They fail in a short time frame and need to be inspected and re-applied on a regular basis.



EonCoat reduces application time by about 50% due to easier surface prep standards and fast-curing properties. Once applied, EonCoat’s proprietary dual-layer formula eliminates the need for re-application. All you need is a single coat of EonCoat to protect your carbon steel assets for the life of the asset.

EonCoat CUI will reduce the time you spend maintaining your insulated tanks, cut down on corrosion monitoring and re-application costs, and maximize safety, protection, and uptime.

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