I just finished making a rudder
for my boat (Catalina 30).
The total cost was around $800 or so.
It was made following the procedure shown at the Foss foam and Jeffa companies sites. The Jeffa (Denmark) rudder
making video was very helpful.
- The old rudder was used as the pattern to make a split mold
. The picture of the mold
below shows how good I am at adding pigment to resin.
- 16 lb (cu ft) foam poured into the mold containing the new rudder post and armature.
- Rudder post- 316L (Schedule 80) 2" (1/4" thick wall both sides).
- 1/4" plate 316L Stainless "armature" (I call it a flag) welded to the post.
- 9 "keying" holes Laser cut into the armature.
- Foam glassed over with 2 layers 1708 biaxial cloth.
- one finish layer of 12 ounce cloth.
- 3/8" "eye-bolt" epoxied into the rudder post so I can remove and install the rudder while in the water
and not have to worry about it dropping to the bottom of the ocean.
The old rudder made by (I assume) Catalina
was glassed over "bondo" and very weakly constructed. 1 layer of Coremat was used with a single
woven glass layer finishing it.
The rudder post was cheap
316 Stainless with 1/2" 316 Stainless bars welded to the post. The bars were bent and then welded to the rudder stock. They were severely degraded at the bends probably from moisture.
The "bondo" was entirely cracked into 2-1/2" pieces and show signs that the cracking occurred many years ago.
I had considered using Carbon fiber cloth and a Carbon fiber post and armature but CF is electrically conductive and a galvanic reaction would be established. So, I stuck with 316L as it's easier to work with and won't "flail when it fails".
The only problem remaining is how to electrically isolate the Edson
radial from the rudder post.
Making a rudder is very easy
Use West System epoxy
No matter what rudder stock material you use it will eventually fail in salt water