[Rhodes22-list] What's the centerboard made of?

[Graham Stewart]

Tom:

I don't want to alarm you but there may be more serious problems that you
would want to rule out.

If the centerboard has started rubbing against the sides of the centerboard
slot, I think you need to determine exactly what the cause is. This is
particularly the case if your boat is subject to winter freezing.

Water can make its way into the centerboard and/or the housing where, I
discovered, there were many substantial voids. Water freezing will expand
the sides. Just sanding down the surface will not fix the problem in
this case.

Use something like a tack hammer to thoroughly tap the sides of the board
and and housing listening for dead spots that indicate voids. Also, check
carefully for signs of expansion such as fine cracks. You might use a
straight edge on the housing sides to see if they are bowed.

Fixing the centerboard is not too difficult. if you find voids you can
drill holes into the voids and inject epoxy into them using a large
syringe. You need two holes for each void - one to inject the epoxy and the
other to allow the air to escape. Fill the void until the epoxy comes up
the air hole.

The sides of the centerboard can be sanded down but if you go through the
gelcoat you need to fix the surface with epoxy.

If the problem is in the housing, the fix is considerably more difficult
because there is no easy access.  In my case, I found that the bottom of
the keel had a huge crack that completely encircled the centerboard slot. I
think that damage was caused when a previous owner put a board under the
keel when the boat was on the trailer. Big mistake!  I would check that
out.

By drilling a lot of holes into the keel from the outside and down through
the bottom of the boat, I was able to fill the voids, as best I could tell,
with polyester resin. I used polyester resin because it is much cheaper
than epoxy and, in this case, I was not looking for strength. It took 3
gallons of the stuff! That was a LOT of room for water,

Once the core was filled with resin, I was able to sand down the inner
walls of the slot. I put a very coarse sanding disk on a pad that I then
attached to a rod attached to a reciprocating saw to sand those surfaces.
It worked but was not a job I would want to have to do again.

 Hopefully, this is not what has happened to your boat but I would want to
rule it out.

The age of your boat might be an important factor to consider. The older
boats were not built nearly as well as later boats. Mine is 1976 which
places it squarely in the "old boat" category.

Lou Rosenbourg (I might have his last name spelled wrong) documented
extensive repairs to the inside of his centerboard housing and all that
information is in the archives.



Graham Stewart
Agile 76


On Wed, May 22, 2024 at 7:20 PM Tom Hyatt via Rhodes22-list <
rhodes22-list at rhodes22.org> wrote:

> I am having an issue with my centerboard not dropping when I release the
> line. All of the blocks seemed to be operating correctly. So I pulled the
> cap and removed the centerboard (with major difficulty)
>
> It appears that the board is rubbing against the opening where the fattest
> part of the board fits into the centerboard slot. I think I want to sand
> down the centerboard in this area but I have no idea what its composition
> is and how much can be sanded safely (if at all).
>
> The other option is to sand inside the slot but that seems to present more
> issues with getting any sort of tool up there. Hand sanding that part would
> be an option.
>
> Any help would be appreciated.
>
> Tom Hyatt
> Eliza Jane, 1978
> Middle River, MD
>