Some of you may recall when Bob noticed a crack in a photo of my
fairlead collar. That was almost a year ago, I think. I talked to
Mike Quill about it and he said it would be OK to sail it like that
for a while as long as I didn't push the rig hard. So I've been
raising the sail just until I saw the tack shackle start to lift and
stopping there. That left the luff a bit loose and I've been happy
that the boat actually sailed pretty nicely even like that.
I bought a new fairlead collar and in December I started to
replace it, only to find some corrosion beneath the tack collar.
There were a few paint bubbles visible with the collar on, but it
didn't look bad at all until I removed that collar. After extensive
consultations with Mike and with Klacko Spars, it turned out that
the corrosion was well within limits. (The wall thickness of the
mast is 1/4" in this area and the corrosion was mostly just
superficial.) So Mike advised me on the repairs.
I first sandblasted the corrosion and then treated it with a
chemical from Star Brite. (Sorry, I forgot the name.) Then I
primed with an aluminum primer, an epoxy primer and painted with
two-part polyurethane - all from Interlux. I put the old tack
collar back on with new neoprene beneath it, installed the new
fairlead collar with a dab of Sikaflex on the "ears" to prevent
twisting, and put on some new mast bands with neoprene beneath them.
I did all of this with the mast up, so didn't paint anything
above about 7' off the deck. But that lower 7' looks pretty good
now. :-)
Yesterday morning a friend and I put the sail back on and took it
out for a trial. I raised the sail all the way up and tightened the
luff. It was a breezy day and we hit 8kts (GPS) within a few
minutes of raising the sail. That's a full knot more than the best
I've ever been able to manage. I de-powered a bit because my
friend's wife's eyes were getting too big, but we sailed for a few
hours, rarely getting below 6.5kts. It was a very brisk and
enjoyable sensation for a change, rather than worrying about the
cracked fairlead collar. I'm not a racer, but the improved
performance tells me that the boat can now sail correctly.
Then I had to dock the giant windvane in my downwind slip in all
that wind. I didn't hit or damage anything, but it took two tries
and was not one of my finest moments. I am moving to an upwind slip
on March 2nd. Hopefully that will be better.
The tack collar had a rotted and crumbling piece of red rubber of
some sort beneath it when I took it off. According to Klacko, this
allowed salt water to get down in there and led to the hidden
corrosion, made worse by the galvanic reaction between the aluminum
and the stainless. I used neoprene when I put the collar back on.
(Solid sheet, not foam.) The collar fits tight and this should keep
salt water out from between it and the mast. It will also protect
the paint and keep the two metals apart - as long as it is in good
condition. I intend to remove the tack collar occasionally, clean
out any salt that manages to get in there and replace with fresh
neoprene.
This has been grueling and a bit scary until I understood
everything. I'm sure the old timers here know it, but for everyone
else: keep a close eye on the various bands and collars that wrap
around your mast. If you see even the tiniest bubble of corrosion
around an edge, or if the padding beneath the collar looks dried out
or worn, take it seriously. I caught mine before the damage was too
serious, but during one of our consultations, Mike Quill sent me a
photo of a mast that broke off due to corrosion beneath the tack
collar.