Toller wrote:

Oak is about 50% heavier than mahogany, but I actually want the weight, so
that is not a problem. Besides, it is free and the cedar would be about
$50.


What you are describing is a disaster guarenteed to happen.

As someone suggested, use the oak for something else.

Might even barter it for some good foam, but these days, good white oak,
even 8/4 is cheap compared to foam, even Divinycell.

Cover the foam with some 17 oz double bias and epoxy.

SFWIW, the above describes how my rudder will be built.

Lew

What you are describing is a disaster guarenteed to happen.

Why?
The mahogany board weighs 15 pounds. The oak board should weight about 23.
Even if I hadn't just lost 7 pounds, what severe problems will the 8 pounds
cause?

I am not being argumentative; I concede I don't know anything about boat
building, and little more about sailing. But I have sailed this with my 95
pound son in it, and it is fine (if a little sluggish); why would 8 pounds
of board matter?

Toller wrote:
What you are describing is a disaster guarenteed to happen.


Why?
The mahogany board weighs 15 pounds. The oak board should weight about 23.
Even if I hadn't just lost 7 pounds, what severe problems will the 8 pounds
cause?

I am not being argumentative; I concede I don't know anything about boat
building, and little more about sailing. But I have sailed this with my 95
pound son in it, and it is fine (if a little sluggish); why would 8 pounds
of board matter?




It is not the added 8 lbs although rudders are designed to be as light
as possible.

It is that this is not a good application for white oak.

Now if you quarter saw that 8/4 stock, you can make some very nifty trim
for tha boat.


Lew

"Toller" wrote in message
...
What you are describing is a disaster guarenteed to happen.

Why?
The mahogany board weighs 15 pounds. The oak board should weight about
23.
Even if I hadn't just lost 7 pounds, what severe problems will the 8
pounds cause?

I am not being argumentative; I concede I don't know anything about boat
building, and little more about sailing. But I have sailed this with my
95 pound son in it, and it is fine (if a little sluggish); why would 8
pounds of board matter?

Without looking at the board and reading the grain, it is near impossible to
tell what it will do. Not knowing how old it is and how it was dried
muddles things further. I don't think the weight is a concern. I would
think warping, bending, settling, etc. of the board is the potential (big
word there) cause for concern. A guaranteed disaster? I hardly think so.
A likely disaster? Nah. It is yours, the board is free. The penalty will
be to redo it. Go for it, it might just work!

Ed