KHIA headerKnow-How in Action

VOL XXXII, NO 177

Belzona® Protects Ships Rudder From Cavitation

 
 

Industry:

Marine (MRNE)

 
 

Application:

Ships and Offshore Structures (SOS)

 
 

Customer Location:

Guangzhou

 
 

Application Date:

October 2013

 
 

Application Situation:

A shipping company based in Korea have a large selection of ships operating throughout the world. When they need maintenance they dock in China. Ahead of an upcoming docking period, a Belzona representative had successfully specified a solution to fix a problem with the rudders.

 
 

Problem:

Due to the nature of the shape of a rudder, coupled with disturbed water flowing from the propellor, cavitation damage was aparent on the rudder. Previous attempts to resolve the situation involved overlaying with stainless steel. This led to galvanic corrosion in places and did not stop the cavitation.

 
 

Products:

Belzona 1311 for rebuilding
Belzona 1341 for priming
Belzona 2141 for coating

 

Substrate:

Stainless and Mild Steel

 
 

Application Method:

Following surface preparation, All pitting was filled and rebuilt with Belzona 1311. Belzona 1341 was then applied as a 1 coat system straight over the Belzona 1311. Once the Belzona 1341 had cured, Belzona 2941 was applied to the areas where Belzona 2141 would be applied. Belzona 2141 was then applied in a 2 coat system with the top coat as black.

 
 

Belzona Facts:

Previously stainless steel had been bonded over the mild steel rudder. This led to galvanic corrosion and also did not completely stop cavitation. Belzona were able to reclaim the corroded material and protect against the cavitation effects.

 
 

Photographs Description

Photo 1 - Overlaid stainless steel corroding and cavitating Photo 2 - Damaged area rebuilt and coated Photo 3 - Full coating system applied Photo 4 - Final View

 
Case study pic one

 

 
 Case study pic two

 

 
 Case study pic three

 

 
 Case study pic four

 

 
 
For more information about Belzona visit: www.belzona.com