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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.
Caution; Do not loosen any
piece of rigging off completely unless you are certain there
is something else holding the mast in its place.
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 within 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 turn
freely and the threaded part should be perfectly straight. This
is a problem area on trailer boats 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 re-assembling the rigging screw,
lubricate the threads with marine grease. A little goes a long
way and is only useful where the threaded part contacts the rigging
screw barrel. Split pins which have been correctly installed
can be re-used 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 sourced copies of a major U.S. brand
rigging screw which failed 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 with debris 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 signs of cracking and corrosion. |
Aluminium mast and boom sections
should be free of corrosion. Corrosion is mostly found where
there are dissimilar metals, in this case 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 and should be attended
to professionally.
To prevent further corrosion
1. 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.
2.You may need to use a revolving s.s.
or brass wire brush attached to an electric drill to remove corrosion
in areas of pitting. The idea is to get as close to shiny metal
as you can.
3.If the fastening holes in the aluminium
are enlarged from corrosion you'll need professional help to
rebuild the area.
4.As long as the pitting is minor, go
ahead and re-bed the fitting using either a physical barrier
like thin rubber sheeting, or Duralac anti-corrosion compound,
or a combination of the two. Use Duralac or an equivalent barium
chromate paste on the thread of all stainless steel fastenings.
Hint To remove frozen machine screws.
If the fitting has caused corrosion you will usually find the
fastening screws are 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. If this doesn't work then judiciously applied
heat should do the trick. (ed’s note; transmission fluid
also works well as a penetrating lubricant)
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. Another tool worth trying is
an impact screwdriver. With any of these methods, the first step
is to soak with WD40.
Paint and corrosion
On painted spars it's common to see corrosion under the paint.
It manifests as chalky bubbles in the paint which will continue
to promote corrosion until removed. This type of corrosion is
usually found in conjunction with fittings of dissimilar metal
to the spar, or where the aluminium has been inadequately prepared
for painting. See photo “A” above.
The short term remedy is to scrape the
paint away from affected areas. It looks unsightly but cosmetics
are less important than preventing further corrosion. Eventually
the corrosion must be cleaned up, its cause removed and the spar
repainted.
The Verdict
Once you've gone over your rig the way I've suggested you will
have a good idea of its condition. At this point you may decide
to enlist professional help but what you've learnt from this
guide will help to evaluate the advice of your rigger.
To complete a thorough check of your
rig you'll need to go aloft. The next issue of TCP covers working
above deck. The thrills, the spills, the FEAR! Don’t miss
it.. |
