View Full Version : keelmaterial for an alu sail boat!
nukisen
10-25-2009, 06:30 AM
Hi all!
I am planning to build a small aluminium sailor.
though I do want the keel to have a higher dens. then aluminium.
Of course I dont want the alu to bee corrogated by galvanic streams.
Any suggestions of a good material! Not to expensive of course.
The keel is still under design and should be a little deeper and a little bit shorter. The same opt. with the rudder.
The data in the pdf file isn´t correct.
Ad Hoc
10-25-2009, 06:42 AM
Have you done any calc's, to confirm that you actually need a higher density material, for your righting moments?
nukisen
10-25-2009, 07:18 AM
Yes i do have a righting moment of about 0.47 knewton at 60 degrees. And i am not sure how much a sail does press the boat at the side. I do have a vert cog about 0.45 with myself placed on the durk. I am sure that you meant the boat boat to be as light as possible. And the hull is about 20kilos at the moment. If I do use Alu. The vertical Km is about 0.67meters above lowest point at bottom (without keel inkluded).
gonzo
10-25-2009, 07:36 AM
A lead filled aluminum keel can work. You can cast the lead to the shape of the keel and set it in epoxy.
nukisen
10-25-2009, 07:40 AM
Actually I did have this in my mind. But I wasn´t sure about the galvanic. But you mean this wouldn´t bee any problem to corrugating the alu in salt water.
Of course I will use alu Aw 5754 wich is saltwater resistant.
nukisen
10-25-2009, 07:42 AM
Ad Hoc!
I also have to calculate the sail before I make the boat heavyer.
thx!
Janne
gonzo
10-25-2009, 09:42 AM
The lead and aluminum will not touch if the lead is encapsulated in epoxy
nukisen
10-25-2009, 12:10 PM
Ah oki!
Then I can use any material as I want.
:)
View Full Version : keelmaterial for an alu sail boat!