Okume is not hardwood it is softwood, as such it is often covered in
fiberglass. In France we use Moabi plywood with f/g but I'm not sure
if its available in your area.

Mason Pan wrote:
On Sep 11, 12:00 am, "Toller" wrote:

My Potter 15 rudder is made of 4 pieces. The top is a solid core about
10"x15", with two pieces ofplywoodscrewed to it on either side measuring
10"x30". The solid blade mounts between theplywood, below the solid top.

One side of theplywoodis falling apart, and the other side isn't doing
much better. I went to the lumber yard today to buy someplywoodto replace
the bad parts. They have Marine Fir and Marine Okoume. They told me that
neither will be durable; they have to be covered with fiberglass. If that
is true, it certainly explains why the original is falling apart, as it is
not covered in fiberglass.

I bought a piece of fir, which I will cover with spar varnish just to get me
through the end of the year. This winter I will rebuild the whole thing.
(neither the top core nor the rudder blade are looking real good either).

What is the story onplywood? Is nothing suitable for marine use without
being fiberglassed? Would solid wood (3/8") substitute? Any advice on how
I go about doing this so it is durable would be appreciated.


You can buy a marine plywood as the following:
Species: hardwood(red hardwood like Okoume is better) or birch
Glue:best Phenolic glue
The core should be void free .

Mason Pan
http://www.plywood.cc/