Protank Shaft Tube Pipe Repairs & Preservation

Professional tank cleaning owns several types of specialized equipment designed to clean, blast & line the interior of cylindrical areas on a vessel where protective coatings are required including: shaft tubes, sea chests, exhaust trunks, deck drains, tank transfer pipes, exhaust stacks, etc.  We often find that there is insufficient or a total lack of coating / lining on the interior of these areas.  If left unprotected significant rust scale or corrosion deterioration will occur as well as marine growth which will negatively affect the performance of these areas. 

We provide turnkey coating system solutions for these areas.  Standard procedures for preservation of these areas include:

• 40,000 psi Ultra High Pressure Waterblasting to remove salts, contaminants and marine growth that would otherwise become impregnated into the metal causing pre-mature coating failure as would be experienced with conventional sandblasting.  All existing coating and corrosion is also removed during this process.
• Inspect and test the surfaces for adequate existing surface profile.  If one does not exist we will brush blast using a variety of specialized nozzles to produce the required surface profile by the coating specifications.
• Fill and fair in all pitting and reform wasted areas with the appropriate metal repair product.
• Apply a protective coating system in accordance with all product specifications.

We were recently hired to provide a very specialized service to this 290' megayacht. They have an onboard fresh water swimming pool, and while underway the water is drained into a holding tank. When the boat was built the pipe connecting the pool to the tank was not coated. Take a look at the next picture to see the result.

Spinblast nozzle in action.

Specialty spinblast nozzle to sandblast the interior of pipes 8" to 18" in diameter.

The pipe in question. Note the stalagtite-like formations of rust.

The first step was to pressure clean (with fresh water and a spinblast nozzle) the pipe interior to remove rust scales and chlorine related contaminants to prevent the sandblasting procedure from impregnating the metal pipe with any a contaminants--which would lead to a coating failure (and a rusty swimming pool!).

Then we use a 360-degree pipe interior sandblast nozzle to further remove rust scale and profile the metal to 2-3 mils depth (according to the Sigmaguard CSF 585 paint spec sheet).

Finally we use our pipe interior spin-paint system to apply the final coating. This coating can be expected to last at least 20 years or more.

We provide color video inspections for both before, during and after our cleaning a preservation processes.  With the addition of our new WHOLER Vis 220 we can inspect pipes as small as 1 ¼” and up to 65’ away and is perfect for the following applications:  deck drains, plumbing systems, shaft tubes, exhaust systems, sea chest plumbing, air ducts, underwater hull & appendages.

Grit blasting the interior of a vessel’s deck drains.

Grit blasting the interior of a vessel’s deck drains.

Deck Drain after lining with a protective epoxy coating.

Contact us for further information on any of these services.