C5-M Typical coating system

More about selecting coating systems for general steel constructions including C5 in our Guide to ISO 12944.


A high durability coating system for environmental conditions classified as C5 M-very high corrosivity (marine) *

Substrate: Steel
  C4 - high corrosivity according to ISO 12944 C5 I - very high corrosivity according to ISO 12944 C5 M - very high corrosivity according to ISO 12944
Expected durability
(acc. ISO 12944)
Low Medium High Low Medium High Low Medium High
Surface preparation: Blast cleaning to Sa 2½ according to ISO 8501-1.
The substrate must be dry and free from salts and other contaminants. Prior to blast cleaning, oil and grease should be removed by solvent cleaning according to SSPC-SP1. Remove weld spatter and smooth weld seams and sharp edges as applicable. Sharp edges, weld seams, corners and other areas that are likely to receive less dry film thickness than specified, should be stripe coated.
Please read the actual product datasheet for more information.


Paint system
Layer Product name Description Volume solids (%) DFT (µm) Theor. spreading rate (m2/l) Recoating times at 23°C.
Min. Max.
1 Transozinc Epoxy primer Epoxy polyamide 55 75 7.3 6 hrs. Indefinite
2 Transpoxy Masterbond Epoxy polyamine




12 hrs.


3 Transpoxy Masterbond  Epoxy polyamine 
12 hrs.
4 Transurethane Finish HB Polyurethane




12 hrs.



Total system DFT



* Since the update of ISO12944-2 in 2017, the C5 industrial and marine envvironments, C5I and C5M, have been replaced by a single C5 (very high corrosivity) environment.

  • Industrial areas prone to high humidity and chemical attack. Coastal areas with high salinity.
  • Facilities exposed to permanent condensation and chemicals.

As the letter 'm' is used to abreviate medium durability, it is important to check what durability/environment combination is the basis for the coating system design when C5M, C5-M, C5m or C5-m is used in a design specification.

The information in this system specification is provided for information purposes only. For more details about the use of the stated products, refer to the relevant product data sheet. As we have no control over either quality or condition of the substrate and other factors affecting the use and application of the products, we cannot accept any liability whatsoever or howsoever arising from the performance of the product or for any loss or damage arising from the use of this product, unless otherwise agreed in writing. All products and advices are subject to our standard terms and conditions of sale, which are available on request. For further information regarding prices, availability and technical information consult your Transocean Coatings representative.

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