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Author: Mike Bruzzone ([email protected]) contact the author Subject: Aft-Lowers Info: (22350 views) Posted: Friday 7-20-07 07:10:36 AM |
First, all boats at the age of e27s need there chainplates and fasteners inspected where they go through the deck. If you have leaks, pull the fittings and inspect for rot in the core of the deck and where the chainplates fasten through the bulkhead. I have never experienced rot through the bulkhead where the chain plates attach. But, have repaired rotten balsa in the deck where fittings, go through the deck, using west epoxy mixed with glass fibers.
Second, after lowers, if the below deck braces for your after lowers are still attached to the knee of the mini bulk that makes up the seat down below; with a bolt through 'bent' marine eye, get rid of the bent marine eye. The bent marine eye is what has failed down below in the past. The head of those stock factory bolts have also sheared off from time to time.
The fix requires using a U-bolt fastner; I think the one on my boat is 5/32 (the same size used on many boats to lead the genoa sheet to the main winch).
To install the U-bolt, use the existing hole as a guide for one leg of the new U-bolt (the upper leg toward the deck side), then, drill a second hole through the cleat plus upper knee of the seat (lower side), where the plywood glues to the cleat. This will likely be down and out board of the existing hole. That cleat is what the seat slats screw to and its glasssed into the hull at the mini bulkheads that make up the aft side of the table and galley unit. Take a look and you'll notice the bottom leg of the new U-bolt will now go through, and pick up, two pieces of wooden structure. The top leg will remain through the plywood only.
That U bolt and its two legs, are secured through the cleat and plywood knee (bottom leg) and the original hole which attached the marine eye (upper hole).
Note that the existing hole and the second lower hole that you drilled, must allow the U-bolt legs to seat in a parrallel load path with the wire brace at the angle in which it leads to the strap at the under side of the deck for the afterlowers. Now that you've got a nice U-bolt bolted through two pieces of wood with legs angled in parrallel with load path, you can attach the U-bolt to a real marine eye swedged to a turnbuckle; the U-bolt end will now ride nicely on marine eye as integral to the U-bolt. At the under the deck end of the wire brace swedge a fork with clevis pin.
For tuning the brace under the deck, tighten until you see the deck dip downward and then release 1/2 turn. For the after lowers tighten until you see the invesrsion in the rig and then let off 1/2 turn. I dont, but some people have turnbuckles on the afterlowers with levers for adjustment between races.
mb
:: Thanks Will.
::
:: :: Good question.
::
:: :: I set mine up with the lowers completly slack and put as
:: :: much tension on them as I can without deflecting the
:: :: deck. They will certainly load up plenty when going
:: :: upwind with the backstay on! Having the tie downs at the
:: :: right tension is a key part of headstay tension through
:: :: the aft lowers. If they are too loose the deck will flex
:: :: alot, the fitting will leak, and the rig will be bending
:: :: more than you think.
:: ::
:: :: Warning- I have seen at least one boat that lost its rig
:: :: because the structure at the bottom of the tie down
:: :: failed and the loaded aft lower went through the deck. I
:: :: don't know the full history but it is possible that
:: :: later boats had their structure up graded or the
:: :: addition of the inline lowers and reduced weight limit
:: :: solved the problem. Watch for small cracks and if yours
:: :: looks fine then it is probably ok.
:: ::
:: :: Also I have seen boats damaged or a mast lost because
:: :: the part of the tie down wire failed.
:: ::
:: :: Very unfortunately as was shown at the 'light air'
:: :: nationals- it is a good idea to replace the old wire on
:: :: your boat periodicaly. Most riggers would say 5-7 years
:: :: of racing and you should consider it. If part of the
:: :: wire on any of your standing rigging has more than 10
:: :: seasons of hard racing on the bay then you should
:: :: consider doing it ASAP. Also I replace my wire lifelines
:: :: every 2 years if they need it or not. I would tell a new
:: :: boat owner to automaticaly change all of it if its
:: :: history is at all unclear. It is my personal opinion
:: :: that the rod uppers last much longer than the woven
:: :: wire- but all should be carefully inspected
:: :: periodically- like where they turn at the spreader tips.
:: ::
:: :: I hope that helps!
::
:: :: Cheers,
::
:: :: WP
:: ::
:: :: :: Aft-Lowers: It there a set-up proceedure that seems to
:: :: :: work in tensioning the under-deck support cables for the
:: :: :: aft-lowers...the ones that run from under the deck to
:: :: :: the bulkhead. If they are too lose, its difficult to
:: :: :: maintain a consistant tension in the aft-lowers, the
:: :: :: deck will be pulled up/develop cracks and leaks will
:: :: :: occur. I don't know what will happen it they are too
:: :: :: tight. Will the deck crack in that situation also? Will
:: :: :: the fitting leak also? I experienced some water leakage
:: :: :: at the aft-lower deck fittings during the "windless"
:: :: :: Nationals and before I attempt to seal the fittings, I'd
:: :: :: like to know how to set them up. It would be nice to set
:: :: :: up these suport cables and not to touch them when I
:: :: :: adjust the aft-lowers for specific races.
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