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Bow Thruster Tunnel Protected



Marine (MRNE)



Ships and Offshore Structures (SOS)


Customer Location:

Pacific Northwest


Application Date:

April 2015


Application Situation:

Vessel in shipyard required resurfacing of bow thruster tunnel before launch. The owner was unaware of the problem prior to the vessel being hauled. Timely response was in order.



Thruster tunnel was pitted and eroded in areas near thruster propulsion unit. Bi-metallic corrosion was also a component of the deterioration.



Belzona 1311 (Ceramic R-Metal)

Belzona 1321 (Ceramic S-Metal)



Carbon steel


Application Method:

Tunnel was prepared by first removing several layers of bottom paint and then abrasive blasting to achieve a 3 mil profile. Belzona 1311 was applied to fill the pitting and erosion prior to the application of 2 coats of Belzona 1321.


Belzona Facts:

Vessel owner sought options to cutting out and replacing pitted bow thruster tunnel in private steel yacht. Prior experience in use of Belzona with his dredging company had convinced him Belzona materials were the right option.


Photographs Description

  1. Vessel out of water with hutch built around thruster tunnel for containment.
  2. Tunnel prepared with abrasive blast. Note significant pitting on upper surfaces.
  3. Belzona 1311 applied to pitted areas as seen from inside vessel.
  4. Two coat application of Belzona 1321. Bottom paint will be lapped over Belzona 1321 at tunnel edge.
Case study pic one


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