Projects
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Check
Those Chainplates
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When my wife and I recently purchased a
Bristol-appearing Aloha 32, a thorough marine survey revealed that the
stainless steel clevis pins used to connect the shrouds had worn the
attachment holes in the aluminium chain plates. The survey required immediate
replacement of the chain plates and recommended stainless steel as the
material of choice.
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The old chain plates,
easily removed in about 60 minutes a side, had been made from
aluminium bar stock. One-half inch thick below decks, they were milled
to 3/8 inch thick above decks to accept the yokes for the rigging
screws. Each chain plate also included a backing plate. |
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I fabricated six chain
plate assemblies for about $150 (Canadian) and about 8 hours work with a
hand saw, grind wheel, belt sander, a drill press that was way too small
and a Drill Doctor. Materials were purchased at The Metal
Supermarket, a franchise chain that sells metal the way an old-fashioned
butcher used to sell meat, cut the way you want it.
I used 3/8 inch thick material
for the chain plates, together with a 1/16 inch spacer to maintain the
original geometry. The old chain plates were used as templates for
grinding and drilling.
If you have never worked
stainless before, here are some tips: use a GOOD quality hacksaw blade
that's coarse enough (12 teeth per inch for 3/8 stainless) and keep it
WELL lubricated with cutting oil, three-in-one oil, or whatever. For
drilling, use a slow speed, lots of lubricant and lots of pressure,
enough so that the bit is always cutting a good curl. (300-series
stainless work hardens very quickly if you smear it around without
actually cutting it, becoming impossible in the process.) Most important
of all, make sure your drill bits are razor sharp. (This is where the
Drill Doctor, a precision drill sharpening tool, comes in. I sharpened
my drills after every chain plate.) |
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This photo shows one complete set
(of the six). The new stainless chain plate is at the top, with the
stainless spacer in the middle and the aluminium backing plate on the
bottom.
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If you attempt a similar project on
your Aloha 32, note that the dimensions of the uppers and lowers are different.
Enjoy.
Treat Hull, Aloha 32 "Dileas",
Toronto
Last
updated 12 January, 2006
- © Aloha Owners Association
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