leak into hull from bilge keels
 

Can anyone suggest a way to stop leakage through narrow gaps between
an iron keel shoe and a bilge keel?
The gaps are relative short (a centimetre or three), and possibly the
result of long-term (thirty years) corrosion of the upper surface of
the keel shoe where it rests against the bottom of the GRP bilge keel.
The leakage water appears to travel upwards through the hollow bilge
keels and thence through the GRP hull itself to appear as sweat in one
location and a puddle in another.
The previous owner possibly had the problem some fifteen years ago
because some hard-setting cement compound appears to have been applied
to the keel-shoe interface. The compound is gradually being lost, or
becoming ineffective
I guess a fifteen-year solution would suit me, the question is - how
to go about it.

On 3 Sep 2004 16:39:50 -0700, (David Cranch) wrote:
Can anyone suggest a way to stop leakage through narrow gaps between
an iron keel shoe and a bilge keel?
The gaps are relative short (a centimetre or three), and possibly the
result of long-term (thirty years) corrosion of the upper surface of
the keel shoe where it rests against the bottom of the GRP bilge keel.
The leakage water appears to travel upwards through the hollow bilge
keels and thence through the GRP hull itself to appear as sweat in one
location and a puddle in another.
The previous owner possibly had the problem some fifteen years ago
because some hard-setting cement compound appears to have been applied
to the keel-shoe interface. The compound is gradually being lost, or
becoming ineffective
I guess a fifteen-year solution would suit me, the question is - how
to go about it.
=============================================

I assume the iron shoes are secured with bolts? If so the solution is
just like fixing leaky keel bolts. Haul the boat, drop the shoes,
clean up the shoe tops (remove the rust), replace the bolts if needed,
re-bed the shoes with something like 3m5200, and put it all back
together.

Wayne, that would be a proper job. Unfortunately, the bolts are
unconventionally glassed over. In fact they are almost impossible to
locate and must be countersunk into the thick GRP hull. Although a
surgical approach would be a possibility, GRP lockers are built over
them on the starboard side, and the wooden galley and pilot berth on
the port side.

Thus it is not surprising to find no reference in the literature to
this kind of approach. That's why I believe an external patch-up job
is needed.

On 5 Sep 2004 04:16:29 -0700, (David Cranch) wrote:
Wayne, that would be a proper job. Unfortunately, the bolts are
unconventionally glassed over. In fact they are almost impossible to
locate and must be countersunk into the thick GRP hull. Although a
surgical approach would be a possibility, GRP lockers are built over
them on the starboard side, and the wooden galley and pilot berth on
the port side.

Thus it is not surprising to find no reference in the literature to
this kind of approach. That's why I believe an external patch-up job
is needed.
================================================== ====

You could probably clean out the gap between shoe and hull using small
grinding tools, hack saw blades, etc. Once the gap is clean the next
steps would be to inject thickened epoxy, cure, grind the edges
smooth, and seal with several more layers of epoxy. This is a "band
aid" solution, of course, to what may turn out to be a structural
issue with the shoe bolts.

That is about the best.

One other solution suggests itself, and that is to fill the bilge
keels with a substance that would prevent water rising up through
them. However, given that the state of the interior surface is
unknown, it is difficult to think of a substance that would do the
job.

An off-beat possibility would be a substance viscous enough not to
penetrate the hull and lighter than water, so that it would float on
top of leaking water and thus form a water-tight seal.

Do you think either of these ideas are realistic?

On 6 Sep 2004 16:16:32 -0700, (David Cranch) wrote:

An off-beat possibility would be a substance viscous enough not to
penetrate the hull and lighter than water, so that it would float on
top of leaking water and thus form a water-tight seal.

Do you think either of these ideas are realistic?

=============================================

Probably not. I would try to fix it from the bottom as a second
choice to unbolting the shoes.

bookieb wrote:

(David Cranch) wrote in message . com...

Can anyone suggest a way to stop leakage through narrow gaps between
an iron keel shoe and a bilge keel?

snip

The leakage water appears to travel upwards through the hollow bilge
keels and thence through the GRP hull itself to appear as sweat in one
location and a puddle in another.

snip

No offence meant, but are you sure there's a leak, and if there is,
that it's coming from there, rather than elsewhere in the hull or
deck?

Just the word "sweat" makes me think of condensation...

And the strongest GRP is where the shoe grabs the sock. Least likely
to leak, except around bolts. What holds the shoe on? Condensation
is a possibility. How much water, exactly? Are the bolt heads
glassed over? Grind 'em off and remove them, one at a time, inspect,
rebed, reseat, possibly.

If you must, prop up the hull and shoe, break off all the bolts if
neccessary, re drill and tap, set new keel bolts, seal old holes
with glass, drill new holes for new keel bolts, or reuse old bolt
holes, raise the hull to accept the bolts, or insert them from above...

Rebedding with the finest, of course.

You may be able to cut the bolts externally, with a sawzall.

Notice how one little option can compound it's self?

Maybe a root crack, flexing under load? Clean the bottom to gel coat
all around the foot. Also inside. Grind out and glass old crack.

How much water?

'S prob'ly condensation.

Both the same?

Re wire boat? Change light bulb?

Humidity? Too much ventilation? Good place to keep [beep] cool?

Lemonade?

Terry K

David Cranch wrote:

Can anyone suggest a way to stop leakage through narrow gaps between
an iron keel shoe and a bilge keel?
The gaps are relative short (a centimetre or three), and possibly the
result of long-term (thirty years) corrosion of the upper surface of
the keel shoe where it rests against the bottom of the GRP bilge keel.
The leakage water appears to travel upwards through the hollow bilge
keels and thence through the GRP hull itself to appear as sweat in one
location and a puddle in another.
The previous owner possibly had the problem some fifteen years ago
because some hard-setting cement compound appears to have been applied
to the keel-shoe interface. The compound is gradually being lost, or
becoming ineffective
I guess a fifteen-year solution would suit me, the question is - how
to go about it.

------------

common underwater epoxy putty.....

used for leak repairs all the time in pools and boats. look for underwater
epoxy in a google search.

paul oman

--


"Living on Earth is expensive, but it does include
a free trip around the Sun every year."

At the age of thirty years, the keel bolts should be presumed to be past
their useful life. At the barest minimum, it'd be prudent to remove one or
two to assess their condition. Chances are good that they're significantly
wasted and ready for replacement. This is not a trivial job, but necessary.
If you're in doubt about this, consult a surveyor.

Ignore this at your peril. How would the boat fare if the ballast fell off
and left you with a few new holes in the hull? Before it sank, would it
invert?


David Cranch wrote:

Can anyone suggest a way to stop leakage through narrow gaps between
an iron keel shoe and a bilge keel?
The gaps are relative short (a centimetre or three), and possibly the
result of long-term (thirty years) corrosion of the upper surface of
the keel shoe where it rests against the bottom of the GRP bilge keel.
The leakage water appears to travel upwards through the hollow bilge
keels and thence through the GRP hull itself to appear as sweat in one
location and a puddle in another.
The previous owner possibly had the problem some fifteen years ago
because some hard-setting cement compound appears to have been applied
to the keel-shoe interface. The compound is gradually being lost, or
becoming ineffective
I guess a fifteen-year solution would suit me, the question is - how
to go about it.