Varifold VF4AN zinc anode
Varifold 4 Blade Zinc Specifications
The Varifold 4 blade propeller zinc anode is one of three Varifold folding sailboat zinc anodes stocked by King Propulsion, the USA dealer for Bruntons Propellers.
The VF4AN Zinc is designed for the VF170 style Varifold folding propeller. For this configuration it sits on an anode holder at the center of the hub above the gear mechanism. The zinc is suitable for 4 blade Varifold Propellers over 26 inches in diameter and is the largest off the shelf zinc anode carried by King Propulsion.
Installation of the Varifold Zinc VF4AN
The installation of the 4 blade zinc VF4AN is very straight forward and can be fitted underwater should it be needed. It is mounted atop of the gearing system on a special anode holder. It is possible to remove the anode holder to work on the zinc, (e.g. underwater installation), but for most cases the zinc holder is left in position and the zinc replaced when the boat is on hard standing. By far the hardest aspect will be removing the outgoing zinc. This should be regularly monitored and wear rates can vary depending on many factors including where you berth (steel piers etc.). We recommend not letting the zinc anodes wear below 50% of their volume and for most applications this is typically a season or two, again depending where and how you sail.
Removal of the old zinc is a two part process and best achieved with a pipe wrench. Great care should be taken not to damage the anode holder during the removal. First the anode is fitted with a stainless steel retaining bolt through its core. This must be removed and set aside. Now the zinc can be unscrewed from the anode holder. The zinc anode is threaded with a conventional 1/2 inch BSF thread so once the anode begins to break loose, it should spin on its thread until it is free. It is important not to be too aggressive and damage the hub during this point!
Once the old zincs are removed, the hub should be inspected for damage and the holder that the zinc sits on cleaned to remove any residual zinc, marine growth or hard shell fouling. This is important as the efficiency of your new zinc relies in it being in contact with as much of the parent metal of the hub as possible. This may require a wire brush or emory paper to clean it but again try not to remove parent metal as much as possible.
Once everything is clean, the zinc can be installed. The zinc will thread on like a propeller nut and can be tightened with the pipe wrench to make it lock. Once in position this zinc has an additional bolt that passes through the center of the zinc and secures it to the anode holder for a more secure application. The zinc should be true to the surface of the anode holder and ready to be returned to the water for service.
Final thoughts on the Zinc Anode
Incidentally, the other part that needs to be services on a regular basis is the buffer pads (seen black on the photo). These are the cheapest part we sell but are responsible for so much. The buffer pads cushion the blades as they open and without them the blade can develop structural issues from the loading – be sure to check them!!
Lastly, keep an eye on the zinc during the year, steel piers, electrical connections or heavy onboard power use can all cause the zincs to wear faster. Loss of the zinc will make the cathodic process inherent in the boat pull the zinc from the propeller instead giving you a pink propeller. This means it is rich in copper and hence softer. This is one of the main causes of early propeller replacement so be sure to keep an eye on things
For any additional information call the office on 757.962.9219 or get in touch on firstname.lastname@example.org