Excellent results Transocean in Benchmark test

Recently the corrosion resistance of some standard Transocean epoxy coatings were compared against well-known other brand products.

The comparison was done by salt spray testing in accordance to ASTM B-117. This test is a static test of continuous 5% Sodium chloride solution sprayed on the panels at a temperature of 35 °C.

The paints were applied on 2 type of panels.

The first type was a Cold rolled steel panel blast-cleaned to SA 2.5 (on both sides). The epoxies were applied on the front-side of the panels at the recommended dry film thickness in accordance with the product datasheets. The backside and edges were covered with a standard surface tolerant epoxy.

The second type was the same cold rolled steel panel blast cleaned to Sa 2,5 but then let to weather under natural conditions for several months until an uniform rust layer had been formed. This process of natural rusting takes longer but does results in a more stable and realistic rust layer compared to an accelerated process of producing rusted panels by placing steel panels in salt spray.

After weathering, panels were then washed with fresh water and wire brushed.

The surface preparation quality of the steel panel prepared according to this procedure was qualified as C-St 2-3.

Paints were then applied by spray at the recommended thickness.

Subsequently, panels were air dried for at least 7 days at room temperature before salt spray testing. Each panel was scribed with a horizontal and vertical line, approx. 1 cm from the edge of the panels.

Duration of the test on Sa 2,5 blast cleaned panels was approx. 3500 hours. The test period on rusted steel panels was extended to 4500 hours.

The following Transocean products were included in the test.
All were epoxy coatings.

 Name Description
Transpoxy Barrier High solids universal primer/coating
Transpoxy Guard Solvent free epoxy coating
Transpoxy Masterbond Aluminium Surface tolerant epoxy coating, aluminium pigmented
Transpoxy Masterbond High solids, Surface tolerant epoxy coating
Other brand A Surface tolerant epoxy coating, aluminium pigmented
Other brand B High solids, Surface tolerant epoxy coating
Other brand C
Surface tolerant epoxy coating, aluminium pigmented
Other brand D High solids universal primer/coating
Other brand E
Surface tolerant epoxy coating, aluminium pigmente











In the table bellow pull-off adhesion values measured before and after the test are given. In all cases, adhesion values are good to excellent. In the same table the rust creepage measured from the scribe is stated. Values until 3 mm are considered acceptable.

 Product  Pull-off adhesion in MPa.  Measured under rusting from scribe (creep) in mm.
   Before test  After test  
 Transpoxy Barrier  13,5  11,6  3
 Transpoxy Guard
 12,2  11,3  2
 Transpoxy Masterbond Aluminium  6,9  6,8  3
 Transpoxy Masterbond  11,1  11,1  2
 Other brand A
 9,3  9,5  2
 Other brand B  12,1  9,0  3
 Other brand C  8,4  4,3  4

It can be concluded that the Transocean products performed excellent on blast-cleaned steel as well as rusted steel. Most other brands perform well on blast cleaned steel but in this test clearly give less results on rusted steel.

The excellent results of Transpoxy Barrier and Transpoxy Masterbond on rusted steel were no surprise as both products are used (in some cases one could rather speak about abused) in the market for decades under various conditions and are well appreciated by its users.

Transpoxy Guard is a solvent free epoxy that was designed for potable water tanks and as such complies to the requirements of §§ 30 and 31 (1) of the German Food and Commodities Law (LMBG). The coatings also meets the requirements according to CFR 21 § 175.300 of the US FDA Regulations.

For more information about these products, visit our website or contact your nearest Transocean representative.
Home  »   News  »   Archive