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A RIGGERS ROUTINE ON KEEPING A MAST UPRIGHT

Thursday, 19 December 2019

A RIGGERS ROUTINE ON KEEPING A MAST UPRIGHT

by Petrea McCarthy

A strong, seaworthy rig is a vital part of any cruising boat. But care of the rig is often overlooked, either through ignorance or a conviction that rig maintenance is a mysterious art known only to a select few.

 

On a cruising boat it is worth knowing how to fix things yourself. Even if the budget allows, you cannot always call an expert. Maintaining your own rig might save you some money; maybe even save a dismasting. At the least, you will understand why your rigger charges so much.   

You can implement this inspection as part of your annual maintenance, or in preparation for a trip. The aim is a comprehensive owner assessment of the general condition of the rig, but it is a guide only. If in any doubt, please seek a professional opinion.

Apart from neglect, the main threats to rig integrity are wear, fatigue, corrosion and ultraviolet degradation. The last two figure more prominently in the tropics than cooler latitudes. It is important to keep the effects of hot weather in mind if you intend basing your boat in the north for any length of time.

Obviously, it is easiest to check your rig while the mast is down, but I have written this for the majority who will be doing it with the mast standing.

Most boats these days have aluminium spars and stainless steel rigging, so that is what I will focus on.

We will assume the rig is correctly specified and constructed with appropriate materials.

There are dyes and x-rays available to comprehensively check wires and fittings, but we will concentrate on an inspection any owner can do, anywhere, anytime. Please note that it is always important to employ professionals to regularly check the rigging on your vessel and this information is more of a guide to include rig checks within your general maintenance. 

Running rigging first

Running rigging is all the parts that move, as opposed to standing rigging which is not supposed to. It is prone to wear and chafe - inspect it regularly and eliminate the reasons for chafe. Chafe is caused by movement and happens wherever a line rubs against something.

Lines should lead fair and run over adequate sized, free-spinning sheaves. It helps to get into the habit of checking all visible components whenever you are sailing. Train yourself to notice if anything is amiss: a line leading badly, twisted block, sheet caught up and so on.

To maximise the life of running rigging it is worth end-for-ending each line at least once to even out the wear. This is straightforward with sheets and furling lines but it is also simple to end for end both internal and external mast halyards and reefing lines.

To end-for-end or replace lines

Use the fid to poke a hole through the bitter end of the line, thread venetian blind (vb) cord through the hole and make a long loop fastened with a bowline. You could use the rug hook here – it is easier and faster if there are a lot of lines needing attention.

Alternatively, you can sew the cord to the line. In small boats you could even just tape it lengthways, but this invites trouble if the cord slips.

Hint: If you tape towards the direction of pull, the overlaps on the tape will cover each other (rather like the way you install roofing material from the bottom up to allow the overlaps to shed water). This helps to prevent the tape catching as it’s pulled through.

Carefully pull the line out, leaving the vb cord in its place. Swap the cord to the other end of the line and reverse the process. If you have a spliced eye on your halyard it will have to be re-done at the other end so you’ll need some extra length available.   

Caution: always keep tension on both line and vb cord to prevent snagging. This is especially important with halyards as the weight of the heavier line will drag the cord away from you too fast and this could cause it to catch somewhere.

Halyards with wire

Check carefully for ‘meat hooks’, or broken strands in any wire or wire-rope halyards. Run a rag along the wire rather than risk injury to your bare hand.

Flex the wire sharply in the main wear areas, this will pop any hidden breaks out into view. These hooks indicate that the wire needs replacement.

The areas most prone to fatigue are:

Where the wire sits over the masthead sheave in the hoisted position

Right above the swage sleeve

At the apex of the thimble.

If the wire is still supple it will return to shape when you straighten the bend. If it stays kinked it has reached the end of its useful life and should be replaced. You can actually feel the difference between ‘dead’ and supple wire.

Rope-to-wire spliced halyards obviously can’t be turned end-for-end. If the rope is still good it’s possible to splice new wire to its tail, but this is pretty tedious.

All-wire halyards can be end-for-ended if they have enough spare length. The winch end will have permanent kinks and flat spots from being wound round the winch drum. These kinks won’t run past the masthead sheave so you’ll need to cut back to good wire.

Thread the vb cord into the wire using the hollow splicing fid. Tape it securely into a neat parcel so it won’t snag on its journey through the mast. Pull the wire through as described above. The swaged eye will have to be cut off and remade on the other end of the wire.   

To replace the swaged eye, be sure to use the correct type and size of swage sleeve. Sleeves for stainless steel wire should be copper or plated copper. If your halyard is galvanised wire use an aluminium sleeve.

Sleeves for use with a hydraulic swage press are oval. For a hand-swager, the sleeves should be a figure-eight shape. I recommend having swages done with a hydraulic machine to ensure their strength.

Halyard end fittings vary from the bare end of a rope to spliced or swaged-on shackles or snapshackles. Now is a good time to check whatever fitting you have.

Ensure it is undamaged and working smoothly. Snapshackles may benefit from a drop of light machine oil applied to the spring mechanism. Be frugal here – you don’t want your snapshackle flying open because it’s over lubricated.

Standing rigging

This is all the fixed components which hold the mast(s) in place.

Standing rigging generally fails first at the lower ends so this is the logical place to begin your inspection. If the lower ends are in good shape it normally indicates the rest is OK also. This doesn’t let you off from inspecting aloft, but unless you are about to set off on an extended voyage you don’t need to remove each piece of rigging for inspection if the bottom ends are satisfactory.

Working on one piece of rigging at a time, release the lock nuts or pins on the rigging screws. Mark the rigging screw thread with tape or cable ties so you can replicate this setting after checking the wire. Turning the barrel or adjusting nut clockwise will loosen the tension. Unscrew them until you can release the wire from the rigging screw. Rigging screws tend to seize if not lubricated regularly so if there is resistance, apply penetrating oil or WD40 to the threads and allow time for it to work.

Having visually checked the wire for rusty or broken strands, make a sharp bend at the lower end just above the terminal fitting. This may reveal broken strands hiding just inside the end fitting.

Straighten the wire again. Supple wire in good condition will return to its former shape while fatigued wire which needs replacement will retain the kink.

Next, inspect the terminal fitting on the wire. It may be a roll swaged end, Norseman or Sta-Lok fitting, spliced or a talurit eye made around a thimble. Check for cracks in the fitting, rusting, uneven wire strands or, in the case of an eye around a thimble, broken strands of wire at the bottom of the eye.

Any rigging wire with broken strands should be replaced and so should its opposite number. The rigging on yachts is usually a uniform age, so if one bit is suspect, it’s probably time to ditch the lot.

The rigging screw assembly should be perfectly straight and turn freely. This is a problem area on trailer sailers where rigging screws get caught and bent while raising the mast.

Check all clevis pins and replace any that show signs of wear or corrosion.

While the rigging is disconnected, have a look at the chain plate it was attached to. Signs of trouble here include cracking, rust stains and elongated clevis pin holes. Any of these warrant further inspection of the chain plate, both above deck and internally, especially if there have been leaks in this area.

When reassembling the rigging screw, lubricate the threads with marine grease or lanolin. Remember, a little goes a long way and it is only useful where the threaded part contacts the rigging screw barrel.

Split pins which have been correctly installed can be reused but since their cost is infinitesimal in the scheme of things you could replace them with new ones.

Black or red stains: These tell-tale signs are hard to miss. Black stains emanating from any part of your rig indicate metal grinding away, usually a working part like the gooseneck or sheave boxes.

Rust stains show stainless steel breaking down in some way. Check for cracks in the fitting. Even international brands sometimes use inappropriate grades of stainless in parts of their fittings, rigging screw clevis pins are a common culprit.

Be wary also of inferior brand name copies. I’ve seen Asian copies of a major US brand rigging screw fail in less than a year.

Mast and boom

Once you’ve worked your way round all the rigging, have a close look at the spars.

Check the drain holes at the mast base are not blocked and the mast base itself is clear of accumulated detritus. Does it even have a drain hole? It should.

If the mast is keel-stepped remove the mast boot and check the spar for cracks and corrosion. Corrosion on masts and booms is mostly found where there are dissimilar metals, usually stainless steel fittings on aluminium.

Once pitting has occurred it’s difficult to repair and beyond the scope of this article.

Remedial treatment to prevent worsening of the problem is within the ability of most owners but major corrosion significantly weakens the spar. If you suspect this have it attended to professionally.

To prevent further corrosion

Remove the offending fitting and brush off the corrosion using a stainless steel or brass wire brush. Never use an ordinary steel wire brush as it will shed small particles which will rust and stain your deck. You may need to use a revolving stainless steel or brass wire brush in an electric drill. The idea is to get as close to shiny metal as you can.

If the fastening holes in the aluminium are enlarged from corrosion you’ll need professional help to rebuild the area. As long as the pitting is minor, go ahead and rebed the fitting using either a physical barrier like thin rubber sheeting, Duralac anti-corrosion compound, or both. Use Duralac or an equivalent barium chromate paste on the thread of all stainless steel fastenings which contact aluminium.

Paint and corrosion

On painted spars it’s common to see corrosion under the paint. It manifests as chalky bubbles in the paint and will continue to promote corrosion until removed. The cause is usually poorly fitted stainless steel bits or inadequate preparation for painting.

The short term remedy is to scrape the paint away from affected areas. It looks unsightly but cosmetics are less important than further corrosion. Eventually the corrosion must be cleaned up, its cause removed and the spar repainted.

CAUTION - Do not loosen any piece of rigging off completely unless you are certain there is something else holding the mast in its place

Removing frozen machine screws

If the fitting has caused corrosion you usually find the fastening screws will be seized in place. Instead of forcing them free, which results in damaging the head or breaking the thread, try a generous application of WD40. Allow time for it to soak in, maybe overnight and maybe involving repeat applications.   

If it still will not budge, another tool worth trying is an impact screwdriver along with the WD40. If this doesn’t work then judiciously applied heat should do the trick. Depending on the size and position of the fastening this can be done with the tip of a soldering iron or small butane burner. You need the concentrated heat of these tools as the idea is to heat the fastening and break it free from the surrounding corrosion. A combination of heat and WD40 can be very effective.

Be careful not to melt internal halyards or concealed electrical wiring. With any of these methods, the first step is to soak with WD40.

Down to the wire

To cut wire – Use proper cable cutters if you can. Alternatively, tape the wire tightly at the point of the cut, hold it in a vice or vice-grips and cut with a hacksaw using a fine-tooth blade. (About 24 teeth to the inch) Do this clear of your deck as fine steel particles from the saw blade will turn to rust spots wherever they fall. Avoid domestic bolt cutters you see at the hardware store, they will mangle the wire. If the wire strands spring apart when the tape is removed and resist being reformed to shape, the wire is fatigued and should be replaced.

What you need

Venetian blind cord long enough to reach to the top of the mast and back again

Plastic fishing spool to wind the cord on to, fasten the end of the cord to it to ensure the cord doesn’t disappear up the mast

Small hollow splicing fid or rug hook (from a craft or sewing shop) – not essential, but very handy

Paper masking tape (or PVC electrical tape).

You should already have on board

Spanners to fit the rigging screws

Pliers or multi-grips

Waterproof grease

WD40 (or other spray lubricant) with a small delivery tube fitted to the nozzle

Light household machine oil such as Singer oil or 2in1 oil

Rags

Bosun’s chair.

The verdict

After this exercise you will have a reasonable idea about the condition of your rig.

At this point you may decide to continue and remedy the defects you found, or hire a professional. Either way, you know more than you did before.

At the least this knowledge will help evaluate the advice of your rigger. Better still I hope it gives you the confidence to take on maintenance of your rig just as you do for the rest of your boat.

To complete a thorough check of your rig you’ll need to go aloft. Part two of this article covers working above deck and will be posted soon.

Petrea McCarthy

ABOUT THE AUTHOR:

Petrea McCarthy, editor of the Ideas Locker column in CH, is a former yacht rigger and long-term live-aboard cruising skipper. She operated her own yacht rigging business in Brisbane before going cruising full time, has been involved in both cruising and racing since 1967, participated in all major Australian ocean races, cruised the SW Pacific, Tasman Sea and circumnavigated Australia and Tasmania. Petrea now works as a freelance writer and lives in far north Queensland.

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