Roughness, cavitation, corrosion and surface damage to a propeller reduces it's efficiency and hence raises fuel consumption and can cause other costly damage. A propeller is an important part of any boats equipment, so what do we recomment for propeller maintenance?
The Golden Rule
ALWAYS carry a spare propeller for use in emergencies, a spare propeller may mean the difference between getting your boat home or not. Carrying a spare propeller will mean that you can always use your boat, if you damage a prop you will have another to use. Also if you do damage a propeller you will have one to use whilst your other is being repaired. Propellers can be purchased at reasonable costs and it is more cost effective in the long run to carry a spare so you can use your boat whenever you wish. There is nothing worse than looking forward to using your boat and you can't because you have a damaged prop.
If your propeller is damaged
NEVER run a vessel for long periods with a damaged propeller as you may cause sever damage to your propeller by causing "cavitation burns" or bush failure. You may even damage your engine or stern gear. Apart from seeing obvious blade damage symptoms of a damaged propeller are vibration in use, loss of speed, apparent slipping (cavitation), loss of power, poor fuel economy
Grease the shaft
To avoid problems removing your propeller make sure you grease the propeller shaft with a water proof grease (such at 2-4-C grease) before you fit the prop and make this a routine part of your boats maintenance.
To avoid problems of sever corrosion, propellers and stern gear must NEVER be coated with standard anti-fouling or metal based paints. If you use an anti-fouling intended for use on stern gear and propellers you must ensure that you follow the manufacturers instructions to the letter which usually states that bare metal, particularly aluminium, must be primed prior to application. However, in our experience propellers that are painted with any type of anti fouling are more prone to electrolysis and we would therefore not recommend its use.
Make sure you have an anode fitted to your vessel so you reduce the risk of your propeller and stern gear from getting electrolysis. Don't forget to check that the anode you select is suitable for the type of water you normally keep your boat in, i.e. salt water = zinc anodes or fresh water = magnesium anodes.
Solas Alcup Propellers
If you have a Solas aluminium Alcup propeller you should grease the torsion rods inside the hub with a good quality marine grease such as 2-4-C. To do this you need to remove the plastic nut which retains the bush kit in the center of the propeller. Don't forget this is a left handed thread. Once you have done this remove the bush kit and grease the springs. Re assemble and the job is done. Be careful not to over tighten the retaining nut.
Stainless Steel Propellers
Some stainless steel propellers are prone to discoloration an corrosion. To help prevent this you can use products such as Quicksilver's Corrosion Guard which is a spray giving a clear protective film coating to the metal.
To maintain the best possible performance from your boat you should have your propeller serviced at least once a year or certainly every time it is damaged. Roughness, cavitation, corrosion and surface damage to a propeller reduces it's efficiency and hence raises fuel consumption and can cause other costly damage. Watch out for changes in performance, vibration and loss of speed these are signals that your propeller needs to be serviced.
As a propeller is so important in achieving the best performance from your boat you should not try a "do it yourself" repair as this will probably cost you more in the long run and could result in the propeller being beyond repair, and it may cause other damage to your stern gear. It is very inexpensive to have your propeller professionally repaired and serviced. So why take the chance?.
Propeller Repairs & Sales
240 Merton Road, London, SW18 5JQ, England
TEL 020 8874 7059
The UK's leading propeller specialists trading since 1958