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 EYAA (Endeavour Yacht Association of Australia)
 Modifications
 Keel Modification
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intrinzic
F'ore'ard Hand

Australia
16 Posts

Posted - 05 March 2006 :  8:11:59 PM  Show Profile  Reply with Quote
I have just finished jack hammering the concrete/sludge out of Intrinzic (E24) due to water entering from between the lead section and the concrete section of the keel. The moisture in the concrete over the years has also caused osmosis from the inside out.

As a result I am seriously considering modifying the lead keel by adding the weight of concrete to the existing lead keel. I have been told that the ratio of concrete to lead is around 15-1 which will mean I may be able to reduce the draft slightly to compensate with more weight down under.

If I continued down this path does anyone know:- 1. The weight of concrete I would have to replace?
2. Best way of securing the new keel to the boat?
3. Would it still be within specs?
4. Are there any better options?

I want to be sure that if the hull is damaged in the future it will not soak up water like a sponge where it is almost impossible to remove and/or identify until it is to late.

John from the SWAN in WA.
[:-sonar]

Cheers
John Connell

Edited by - intrinzic on 05 March 2006 8:14:47 PM

Graeme Watson
Helmsman

Australia
253 Posts

Posted - 05 March 2006 :  10:37:30 PM  Show Profile  Reply with Quote
Be careful! The concrete is a structual part of the boat It helps stop the keel from flexing. Adding more weight below and reducing the strength of the upper section of the keel could spell trouble.
Graeme
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Go Flow
Helmsman

Australia
751 Posts

Posted - 05 March 2006 :  10:39:51 PM  Show Profile  Reply with Quote
Hi John,
I wonder if you could have saved yourself a lot of work. By drilling holes into the side of the keel water inside could have been removed. After allowing the concrete to dry, fiberglass resin could have been poured over the concrete to seal off the keel area. After repairing the holes drilled and the osmosis your craft would have been as good as new. I trust you realise the keel bolts were set in the concrete and the lead keel is bolted from underneath. Good luck with your repairs.
Adrian
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Graeme Watson
Helmsman

Australia
253 Posts

Posted - 05 March 2006 :  10:48:14 PM  Show Profile  Reply with Quote
I removed the lead keel from my E24 and resealed it. I let it sit for a while and drain through the bolt holes. I also fibre grassed over the concrete to seal it and used it as the floor. There is a posting on the home page with photos. Have you seen it? It may help.
Graeme
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Sasha
Helmsman

838 Posts

Posted - 05 March 2006 :  10:54:40 PM  Show Profile  Reply with Quote
the keel's draft has more then anything else to do with the boats pointing ability. If you convert to a shallow draft (even if this move is practical, economicaly) then your boat will never sail as close to the wind as a standard endeavour. Just how it goes.

Also, Colin mentioned to me that the issue to stay "within class" is not just boat weight but also boat profile...It basically needs to look like an endeavour below waterline...Though I think that going over to a better shaped rudder ought to be fine.

Having been where you are with my boat Fortis, the keel pocket that the concrete came out of needs significant reinforcement in order to support the keel in the absence of concrete (and not just glassed-in ribs so that the new keelbolts can attach to something). In our boat we went for lead shot in resin poured into the bottom of the keel pocket. The same amount of weight as we removed (we kept it in buckets till we dumped it into the trailer and weighed it on the local tip's weighbridge. Just weigh the trailer coming in and then again as you are leaving empty, the difference plus a few kilos for wastage and dust is how much you need to replace). The lead and resin system has the advantage that the stuff is really STUCK down there and will not come loose in a knockdown or just move around chewing through the hull. It strenghtens the bottom of the keel pocket and it lowers the weight considerably over the concrete, so the boat is somewhat stiffer to windward. A Good Thing.
The extra space in the bilges is also handy.

We have been discussing casting and bolting on two part keel bulbs on another part of this site, so you can take a look there and see if you get inspired to go that route instead...but if you do, you will need to reinforce the keelpocket considerably or the added weight will flop around and stress your hull.

My personal take is that one never regrets reinforcing the leading edge of the keelpocket...LOTS. (from the inside)

One last and possible suggestion is to completely encapsulate the keel. This would involve stripping back some fibrglass around the keel pocket and then using big sheets of glass to just pocket up the whole keel, so that there would be no "external lead" and this ought to keep the water out. One of the melbourne boats has done this, I do not know details about how well it has been working for him since getting it done. It ran to $2.5k for an E26 so it is not the cheapest of experiments.

Again, unless there is a really pressing need, I would NOT reduce the endeavour's draft (remember also that if you reduce the draft past about 6 inches that you will need to start shortening your rudder as well, so it does not get ripped off in a grounding...this way lies madness)


Hope that gives some food for thought.

Sasha

_
The more I know about horses, the more I love sailboats.
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Tod Lewin
Main Sheet Hand

Australia
36 Posts

Posted - 03 January 2013 :  12:09:07 PM  Show Profile  Reply with Quote
Sasha

I don't suppose you remember how much the concrete weighed that you removed? I have also removed my concrete and replaced the fibreglass in the keel and internalised the lead. I've added five bulkheads of solid glass into the keel plus extra stiffening on the sides and where the bilge forms into the hull, but need to consider my options for re balasting. I didn't have the ability to weigh so am having to guess...

Regards

Tod
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