Wednesday, October 30, 2013

Machine & Machinery


Your manual will set out the maintenance requirements here. Do not forget to check your motor anode and the impeller in the water pump.  Think of it is a good idea to replace your impeller each year and keep the old one as a backup.

Also a simple filter on your water intake line between the gate valve and the pump will save a lot of hassles with potential blockages. Wingate" make a simple clear inline tube one and these are available from farm stores, marine shops and garden centre. All hoses should be double hose clamped for safety and checked for wall softening or damage. Replace as necessary. A tip, get your hoses from your local "Hose Doctor" usually a lot more cost effective.

Water tanks and hoses

All water tanks should be flushed clean every year or two and especially if you can "taste" the water. This taste is caused by black algae in the tank or in the clear plastic hoses that runs to your pumps at the sink or the hand basin. Good potable water always contains some solids in suspension and over a period of time these settle out in the bottom of your water tanks.

The best way to drain the tanks is to use a spare piece of hose and connect one end to the tank outlet and the other to the inlet for the motor cooling water. Start your motor, make sure that it is out of gear so the propeller will not turn, and drain tanks and flush motor at the same time! If you don’t have inspection ports in the top of the tank to allow you to agitate the water then remove your deck filler plug and run a hose from the fresh water tap, turn on and stir up the sediment that way.

NOTE: do not let the motor run out of water so keep a good eye on it during this operation.

This procedure can be carried out either on the hard or in the water. (No you most likely won’t have a mains water faucet handy out on a mooring!) If you have clear plastic water carrying pipes I suggest that you change them for black food grade neoprene ones as this will stop any light getting to the water and inducing algae to grow. Enough light does get into the areas where these run for this problem to occur.

Finally you can obtain from you chemist "Milton" solution or water treatment tablets. These can help sweeten the tanks and it is well worth while to consider fitting a small inline activated charcoal filter and make sure that all tanks are well fastened to the hull. Remember that 1-gallon of water weighs 4.5kg so a full 40-gallon tank has 200kgs of potential kinetic energy. Check also that all hoses are securely attached to tail pieces.

TIP: If you ever suddenly find water over the floor boards taste it first as this will determine whether it is fresh or salt and help you to quickly narrow down the possible source.

Before you leave down below take a look at your batteries, gas lines, wiring, switches and lights and your fire extinguishers.

The propeller, shaft, stern tube and stuffing box

Look for wear in the stern tube bush by trying to move the shaft sideways. If you need to replace this you might need to remove the shaft depending on what type of bush you have. For a cut less bearing usually after removing the propeller with a proper prop puller, you can loosen the grub screw or clamp bolt on the side of the bronze housing and grip the cut less bearing with a pair of vice grips, and twist it out.

Most others require that the shaft be removed.

Don’t forget to replace your zinc anode.

When pulling the shaft out from the coupling at the back of the gearbox, if it is tight, place a slightly smaller diameter spacer between the end of the shaft and the gearbox coupling insert some longer coupling bolts through the two halves of the coupling and evenly tighten them up to press the shaft out. Do not use a hammer as this could burr the end of the shaft and when putting the shaft back into the coupling. Do not be tempted to hit the propeller end of the shaft to drive it home, while using the gearbox and engine as a dolly. This will result in the rear gearbox bearing being damaged. While the shaft is out, check for wear and straightness.  Roll it back and forth and watch to see if the ends wobble. If it does, or it is badly worn at the gland end or stern bearing end, get a new shaft made.

Check the stern tube. This connects the outer bearing housing with the inner stuffing box or shaft seal. This is usually a threaded length of copper or bronze tube. Several boats have had a hard to find leak from this area and have found that the stern tube had developed a hole or broken. To remove this assembly you need to unscrew the two outer lag screws, which hold the outer housing to the hull and then unscrew the outer housing and stern tube. Get your local marine engineering shop to turn you up a new one. Reinstall bedding, it down in plenty of high quality marine sealant.

Don’t forget to check your shaft to motor alignment. This should be done each year as the motor mounts do slowly compress. The easiest way is to make sure that the shaft and gearbox couplings are in line and that an equal gap exists between the coupling faces when they are in close proximity. Use a feeler gauge or a set space for this.


On deck strip and service all your winches including those on the mast and don’t forget to grease them well with grease. When you dismantle any winches always check that you block off the scuppers just incase you accidentally drop a pawl, spring or screw.

Check that all the Genoa track bolts are tight and well sealed, as this is a common area for leaks to occur.
An excellent idea here is to slightly countersink each hole in the deck as this enables the sealer to form a "O" ring, which ensures no leaks. This also applies to your stanchion bases, and bolts.

Give all your stainless a treat with a coat of reviver and polish and check the swages on the stanchion wires for corrosion or broken wires.

Have a look at the stays, rigging screws, clevis and cotter pins. Some lanolin grease here helps keep everything free and sealed. Put a little lanolin grease where the wire enters the swages on the bottle screw as this helps seal out water from wicking down the wire strands.

With the rigging wire that is used for the stays it pays to inspect the strands carefully and if you find a broken one replace the whole stay. The recommendation is that you replace all your rigging once every 10 years. Do not throw out the old ones, as these can be kept as an emergency spare. Also look at the spreader tips and make sure that they are bisecting the angle correctly and that the cap shrouds are wired into the ends and that a boot or insulation tape is wrapped well around the ends to protect your Genoa.

Check all your sheets and halyards and if they are showing slight signs of wear, end for end them. This applies for your anchor warps and chain. This is a good time to re-mark the chain and warp with either fathom, or 10-meter marks. Use paint on the chain and colored sailcloth or twine on the warp.

Make sure that all shackles and pins are tight, secure and seized.

The bitter end of the warp should be attached to an eye in the anchor well with some medium lashing to prevent the whole lot going over the side! Do Not shackle this to the eye, as one day you might need to let the whole lot go in an emergency and you won’t have time to fiddle with a spanner undoing a pin! Just cut the lashing with a knife! While checking all this out remembers to check your spare anchors stored below the floor and the dinghies tackle.


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