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tho52mas 05-13-2003 04:17 PM

everyone - need keel solution
I have a problem. My boat -a 37'' Irwin Centerboard model circa 1976. The problem - the bilge leaks into the keep, which leaks onto the ground. In other words the boat was built with sand as the ballast and that was encapsulated, the bottom forming the bottom of the keel, the sides are the two outside sections of hull amd the inside is the two sides of the centerboard trunk, the top is the bottom of the bilge -- the encapsulation failed in three places...the bilge, the bottom and trunk area. WHat are my solutions. 1) is to sink the boat. 2) is to sell it cheap. 3) is to vaccuum out the sand from the inside, repair the keel area from the inside (difficult to do), refill the keel with dry sand, and pour in a new bilge floor. 4)just repair the bilge floor, let the holes stay in the trunk and bottom for drainage for the winter. 5)cut out the keel bottom, let the whole mess fall, clean it out, epoxy the bottom I took out, epoxy the inside of the boat, join the two, refill with sand and put in a new bilge floor (this is really another version of #3). 6)do #3 and instead of sand, use bricks of lead purposely made to fit snug, then pour in epoxy forming a huge, solid keel.
Question? Send me solutions. Thanks. Tom

jparker11 05-14-2003 08:31 AM

everyone - need keel solution

The smart assed answer is to track down the leaks, repair from the exterior and take the boat to Florida to use or sell!!

Reading between the lines, you haul the boat in the winter and expose the now wet ballast to freeze/thaw cycles further exacerbating the problem.

The elegant fix is a modified #6. The lead has a unit weight nearing 700#/CF. It won''t take near the volume or total weight of lead to replace the 90#/CF sand (You can concentrate the higher weight lead lower in the keel structure yielding an equivalent righting moment). With a little effort and a little engineering calculation you can design the lead ballast to provide the equivalent righting moment. Fix the leaks, install the lead, secure with epoxy. In capping the lead in the bilge area, you should end up with a deeper bilge because of the lead/sand conversion. Be sure this area is dewatered during dry storage.

Now, all this is a lot of work. But any of your fixes (save the scuttling option) will be a lot of labor with a relatively small material cost. I can see the overlay work related to trunk repairs will be difficult due to access for surface preparation and laminating. Not mentioned in all this is the new set of skills required to cast lead, epoxy overlaying and epoxy grouting.

The "let it drain" option seems flawed because you don''t know if the current breach is at the low point of the ballast cavity. It will still be subject to freeze/thaw.

How much do you want to have a "bonding" experience with your Irwin?

Irwin32 05-14-2003 09:28 AM

everyone - need keel solution
I say why bother w/#3? It sounds like a lot of work to put the boat into its original set up, which was a bad idea to begin with. Is this just loose sand like you could get at the beach? I have never heard of such a thing.

How much is this boat realistically worth if the repair is done right - using lead etc? Will its value be worth the extensive work we will be putting into the project.

How much money do you have to put towards the purchase of another boat? Maybe this is a good time to let this be someone else''s project while you move on to better things.

Jeff_H 05-14-2003 06:35 PM

everyone - need keel solution
I seriously doubt that Irwin used sand as ballast. In the 1970''s there were companies that used various metals cast into cement as ballast and while I have never heard that Irwin was one of those companies, I am conjecturing based on your discription, that what you may have is concrete mixed with iron as ballast. When the iron gets wet, it rusts and expands shattering the concrete and releasing what looks like sand. There are other possibilities here such as sand was drawn into keel by the leaks and when the water back flushes the other way it is washing back out.

In any event, there is really only one sure way to tell what might be going on in there which would be to take a small coring perhaps an 1 1/2" in diameter in the side of the encapsulation envelop. I would take this into the side of the encapsulation envelope perhaps a foot or so from the bottom of the keel.

Assuming that your ballast is not sand and that it is relatively intact, you have a number of issues to resolve. You need to dry out the cavity, find a way to bond the ballast to the encapsolation, find the leaks and seal them. That is not a small order but with any luck at all it is doable to one degree or another.


soapstone 05-15-2003 07:55 AM

everyone - need keel solution
On my boat, there is vermiculite sand poured in a cavity on the leading edge of the keel. This is to absorb the hit if you run aground without causing de-lamination. You might try to figure out if it''s just a small cavity with "sand" in it that is leaking, or if the (usually iron) ballast is wet and rusting before you decide what to do..

jumpnkd 09-16-2007 01:48 PM

what did you end up doing?
I have the same thing I can see now that tanks are out, trying to figure out the best way to repair as i have a small leak in the centerboard case. I thought these boats came with concrete as ballast. 90lbs in this area for ballast seams light.
Bill White

Freesail99 09-16-2007 01:54 PM

Jumpnkd, This post is over 4 years old.......

sailingdog 09-16-2007 04:25 PM

Thanks Freesail... ;) They gotta start reading dates... if the thread is four years old, often the people haven't been active since then, unless they're a regular.

deniseO30 09-16-2007 05:49 PM

Is the boat nice otherwise?? your lucky if you can access the inside of the keel! remove the sand. fix the glass in a out. Get someone that knows keels of this type to inspect it and see if the whole thing is safely part of the hull. This could be a perfect time to change actual ballast weight too! I've read of people using lead shot mixed with resin (very heavy) sand you know about , cement, but resin is the only thing that would not absorb more water.

jumpnkd 09-21-2007 09:31 AM

freesail i know this post is 4 yrs old but not to ask would be asuming and you know what happens when one asumes.....
Bill white

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