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Bigjim · 15-01-2023, 12:07

When we pulled the boat out last fall the rudder showed some major wear and tear. But it was hard to know how bad things really were under the remaining paint. Yesterday, I used the angle grinder with an aggressive sanding disc to remove the paint and barrier coat. Looks to me like there is some damage to the fiberglass. Do I need to remove the discolored areas? Or can I simply grind it down some more and build it up with new fiberglass, 2-part filler and resin?

Chotu · 15-01-2023, 12:19

Depends a lot on the construction of the rudder. Is there a core? I don’t see it very well in the pictures.

Just depends how saturated that core is.

Kind of looks like it was just slapped together to begin with. Those are some pretty odd looking layers of fiberglass that you are dealing with on the outside of that one side.

Kind of looks like they took whatever was laying around the shop and just laid it up in pic “rudder-05”

SailingHarmonie · 15-01-2023, 12:31

The first picture told me all I needed to know. The internals of your rudder are now full of water. The danger here is corrosion (especially of the welds). There is an internal web of metal attached to the rudder shaft that actually transmits the turning torque to the outer shell. If that web breaks off the shaft, the rudder is useless because the shaft spins and nothing happens.

How likely the damage is to be serious depends on many variables. Quality of the metal alloy used. Skill of the welders. (If it was welded. I have seen the web made of rods that were threaded into the shaft.). If you patch the holes and leave it like that with salt water inside… it will fail at some point. Maybe sooner, maybe later.

I can honestly say if it was my boat, I would drop the rudder and split it in half to get a look at the condition of the internals. I can say that, because I did exactly that on a similar boat.

If you are a bay sailor, close to help, and in water rarely too deep to anchor, risk of loss of steering might not warrant the work. If you are crossing oceans, this should be looked at closely. This is not a young boat, and stuff happens…

It is not a very complex job to open the rudder and have a look. If repair of the metal internals is needed, that can be a bigger deal, but if it is needed, well, it is needed.

SailingHarmonie · 15-01-2023, 12:36

Quote:

Originally Posted by Chotu

Depends a lot on the construction of the rudder. Is there a core? I don’t see it very well in the pictures.

This absolutely is a cored rudder. If it was made of sold GRP it would be so heavy that it would sink when the boat heeled, generating lee helm unless there was constant pressure on the helm.

Chotu · 15-01-2023, 12:39

Quote:

Originally Posted by SailingHarmonie

This absolutely is a cored rudder. If it was made of sold GRP it would be so heavy that it would sink when the boat heeled, generating lee helm unless there was constant pressure on the helm.

Maybe it’s because I am on my phone. I don’t see it that well.

Wondering what it’s cored with. That’s really my question.

But also, to the OP, before you follow the above advice to cut that rudder open, make sure you take a mold of it. Will save tremendous time in reconstructing it.

SailingHarmonie · 15-01-2023, 17:12

Quote:

Originally Posted by Chotu

Maybe it’s because I am on my phone. I don’t see it that well.

Wondering what it’s cored with. That’s really my question.

But also, to the OP, before you follow the above advice to cut that rudder open, make sure you take a mold of it. Will save tremendous time in reconstructing it.

It is cored with foam, there is no viable alternative. I imagine some homebuilt boat has a balsa cored rudder, but given the likelihood of water intrusion that would be a seriously dumb idea.

No, a mold is not needed.

You cut the two halves apart along the seam where they were assembled in the first place. It is how it was made.

The two outer shells are reused when you put it back together., just like when it was assembled in the first place. You do NOT demolish the shape of the rudder! If you are lucky and the internals are not seriously damaged, you don't even have to fully disassemble it, just take off one side, poke around to inspect, and reassemble.

If you want a detailed description of how to do it yourself, that's more than I am going to write here. Suffice it to say, ANY decent marine fiberglass shop has done this specific job many times.

boatpoker · 15-01-2023, 18:46

Quote:

Originally Posted by SailingHarmonie

The first picture told me all I needed to know. The internals of your rudder are now full of water. The danger here is corrosion (especially of the welds). There is an internal web of metal attached to the rudder shaft that actually transmits the turning torque to the outer shell. If that web breaks off the shaft, the rudder is useless because the shaft spins and nothing happens.

How likely the damage is to be serious depends on many variables. Quality of the metal alloy used. Skill of the welders. (If it was welded. I have seen the web made of rods that were threaded into the shaft.). If you patch the holes and leave it like that with salt water inside… it will fail at some point. Maybe sooner, maybe later.

I can honestly say if it was my boat, I would drop the rudder and split it in half to get a look at the condition of the internals. I can say that, because I did exactly that on a similar boat.

If you are a bay sailor, close to help, and in water rarely too deep to anchor, risk of loss of steering might not warrant the work. If you are crossing oceans, this should be looked at closely. This is not a young boat, and stuff happens…

It is not a very complex job to open the rudder and have a look. If repair of the metal internals is needed, that can be a bigger deal, but if it is needed, well, it is needed.

Please pay attention to this ....
Another patch job on this is a certain failure.

Searles · 15-01-2023, 21:08

Looks like toast to me, take some measurements and patterns before cutting into it ,is this off a production vsl can you buy a new one or get detailed drawings ,especially of the rudder stock and palm attachments ,have just finished a largish rudder was full of wet stinking foam ,cut it all out after cutting one side of the rudder out ,ground out and epoxyed the inside shell ,fitted cedar blocks to fill in ,epoxyed the unit ,re fitted the old outer skin ,much epoxy ,better than new .⛵️⚓️

Chotu · 15-01-2023, 21:29

Quote:

Originally Posted by SailingHarmonie

It is cored with foam, there is no viable alternative. I imagine some homebuilt boat has a balsa cored rudder, but given the likelihood of water intrusion that would be a seriously dumb idea.

No, a mold is not needed.

You cut the two halves apart along the seam where they were assembled in the first place. It is how it was made.

The two outer shells are reused when you put it back together., just like when it was assembled in the first place. You do NOT demolish the shape of the rudder! If you are lucky and the internals are not seriously damaged, you don't even have to fully disassemble it, just take off one side, poke around to inspect, and reassemble.

If you want a detailed description of how to do it yourself, that's more than I am going to write here. Suffice it to say, ANY decent marine fiberglass shop has done this specific job many times.

There are certainly wood core (stupid)plywood rudders. This looks like a very old boat from the pics. Barn door rudder instead of balanced spade. So I was assuming too old for foam, even though the color looked like corecell.

I’ve only built 2 rudders (and 2 dagger boards) and I definitely didn’t build a shell before building the core. I built the Corecell core then resin infused the glass onto it. It was a one off obviously so that was way faster.

But whatever. You win. Lol

Chotu · 16-01-2023, 03:59

And it’s even a balanced rudder, looking again.

I guess I didn’t look carefully enough. Was focused on the odd glass hodgepodge in pic 05. Swing and a miss. Can’t get them all right.

Bigjim · 16-01-2023, 13:12

Quote:

Originally Posted by Searles

Looks like toast to me, take some measurements and patterns before cutting into it ,is this off a production vsl can you buy a new one or get detailed drawings ,especially of the rudder stock and palm attachments ,have just finished a largish rudder was full of wet stinking foam ,cut it all out after cutting one side of the rudder out ,ground out and epoxyed the inside shell ,fitted cedar blocks to fill in ,epoxyed the unit ,re fitted the old outer skin ,much epoxy ,better than new .⛵️⚓️

I guarantee to everyone, that this rudder is NOT foam cored. The boat was built in 1978, so there is no foam anywhere on the boat. All the core I have found is plywood. My plan is to use a hole saw to cut into the meat of the rudder to see what's inside. Considering the shape of the rudder, I doubt that there is much if any wood core in it.

As for "water", I suspected that water had intruded a while ago. This is the bane of midwest sailors who have to pull their boats out of the water in winter. Any little bit of water that gets in one year, will then freeze and expand, making room for more water next year. This is responsible for all the water damage on my boat elsewhere. I have found and eliminated most of the other leaks. This obviously, is now my next major project.

Chotu · 16-01-2023, 13:19

Hmmm. Looks like I was way too quick to accept criticism and people pushing my idea down.

. Make sure you keep track of the shape. I’m going to say that again. Even though I got smacked down earlier.

Spot · 16-01-2023, 14:05

Might be worth talking to Foss Foam Products in FL and see if they make that one, could quote a custom, or could advise on the repair.

PS- "My plan is to use a hole saw to cut into the meat of the rudder to see what's inside."
I like this idea too.

Scubaseas · 16-01-2023, 15:09

What Sailing Harmonie said. My 1980 Pearson has no foam core anywhere EXCEPT IN THE RUDDER and looked a lot like yours. Not quite as bad but still there was a lot of damage you couldn't see unless you opened it up. Either cut it open to expose the webbing welded to the rudder shaft or send it off to Foss Foam for a new one.

I did mine in vinylester and biax cloth with two layers woven through the holes in the webbing or "flag" portion. I used foam filler and finished off the skins with three layers of1708 and 1208 with a top layer of veil mat.