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A smooth propeller moves water more efficiently than a rough one. Over time, the blade surface becomes pitted, scratched and covered with deposits that cleaning alone cannot remove. Propeller polishing services in Nagoya restore the surface while the ship is afloat.
Polishing removes a thin layer of deposits and surface irregularities from the blades using rotating tools and abrasive pads. It does not change the shape of the blade or its pitch. The aim is a smoother surface, measured in micrometres of roughness, that reduces drag and helps keep marine growth from settling as quickly.
The Diver first cleans the propeller to remove fouling. He then works each blade in turn, starting at the root and moving toward the tip, using a tool matched to the alloy and the condition of the surface. Pressure is kept even to avoid hollows. The leading and trailing edges are treated with special care, because these thin edges are easily damaged. The cone and the boss are polished too if the owner asks.
We do not rely on appearance alone. After polishing, the Diver checks the surface by touch and with CCTV, and where required a roughness comparator or a handheld roughness gauge may be used. The aim is a visibly uniform, bright surface without scoring or burn marks. The report records the condition before and after.
Reports from the industry suggest that a clean, polished propeller can reduce fuel use by a few per cent in some cases, but the figure depends on the ship, the speed and the starting condition. Polishing does not repair a bent blade or fix cavitation erosion. If the Diver finds damage during the job, he reports it and we discuss the next step with the surveyor and the owner. Always you can reach us. We are servicing every day
The shaft must be locked, the turning gear isolated and the permit signed before the Diver approaches the propeller. A normal polishing job for one fixed-pitch propeller takes 3 to 5 hours, including cleaning and filming. Controllable pitch propellers take longer because of their design.
You receive video of the propeller before and after polishing, photographs of each blade and a report. Many owners keep this alongside their fuel records so they can compare results over time. ClassNK and ABS certification supports our work if a surveyor attends.
Even a thin layer of roughness on a propeller blade increases friction between the water and the metal. On a blade moving fast, this loss is felt in thrust and fuel. Industry guidance often grades roughness on a scale, and a surface that is visibly dull or pitted usually falls in the poorer grades. A polished surface lets water pass more freely and helps keep organisms from taking hold. That is why polishing is often scheduled once a year.
Tell us the propeller type, the number of blades, the diameter if known, the date of the last polish and any recent symptoms such as vibration. This helps us plan the time and the tools for the job.
Q1. How long does it take to polish one propeller?
About 3 to 5 hours for one fixed-pitch propeller including cleaning and filming. Controllable pitch propellers take longer.
Q2. Does polishing change the propeller shape?
No. It removes a thin layer of deposits and surface irregularities but does not change the shape or pitch of the blade.
Q3. How much fuel can a polished propeller save?
Industry reports suggest a few per cent in some cases, depending on the ship, the speed and the starting surface condition. It is not guaranteed.
Q4. Can polishing repair damage?
No. Bent blades and cavitation erosion need separate repair. The Diver reports any damage found during polishing.
