Pearson Mahogany Rudder?

[Quadrille in JB]

This boat just arrived in Florida from Croatia via the Canaries. The bottom and rudder were painted immediately before the trip. The bottom looks great but the 5’ long by 2”thick mahogany rudder worries me. Please see pictures below.
What do the experts out there suggest that we do with the rudder to keep it from eroding?
Thanks in advance

[DougR]

If you're in JB, run down to Fiberglass FL. on Commerce St. in Stuart and get a quart or two of their slow cure, low viscosity penetrating epoxy. Strip the rudder down to good wood and saturate it with epoxy until it won't take any more. Then when that has cured, mix up some thickened epoxy/ cabosil and fair the rudder. Sand and then paint with interlux epoxy primer and then bottom paint. Should be better than new.

DougR

[RGN]

My Pearson Vanguard has a Mahogany rudder that looks very much like the one in the pictures. I have not noticed any bottom paint coming off like that. Do you know the rudder was dry when it was bottom painted? That is a pretty good length trip could a line have been dragged in the water rubbing the paint off?


Anyway if and when you find out the cause post it here, I would like to know the cause too.

[Vinton]

Hi. I just purchased a Pearson Vanguard. The previous owner took excellent care of the boat, and is extremely knowledgeable and experienced. The rudder is original, thinking teak or mahogany, but not sure. His view - and he sailed her forty years - is, leave the rudder as-is. Yard suggested I consider to fiberglass it. Then, I personally was wondering about something like Gluv-it, which I used many years ago on the rudder of a J24, successfully. Not sure where to head. Any thoughts out there? Thank you.

[RGN]

I have a Vanguard with a wooden rudder.


I assume there is no outward reason to be concerned about the rudder? If not, I would leave it alone but keep it well bottom painted. My rudder shaft is marine bronze and is in great shape but you might check that for any corrosion.


I would be reluctant to fiberglass the rudder, if you do, when you haul the boat the rudder will shrink as it dries out and break the glue bonds then you have a real mess. Remember the rudder will open the joins better than 1/8" the fiberglass/epoxy will not shrink.


If the wood is going bad either build a new one one of wood or make up a fiberglass rudder. The fiberglass sheathing is not a good idea in my opinion.


Hope you enjoy your Vanguard as much as I do mine.

[Vinton]

Great points. Many thanks. Seems like building a fiberglass rudder would be the way to go. Is there anywhere you might point me to for that? At least with the existing rudder in good condition, I've got what must be a good template.

[Nicholson58]

I agree re glass over wood.

I have an old Tornado with mahogany center boards. They are durable and gorgeous.

[boatpoker]

Originally Posted by RGN

My rudder shaft is marine bronze and is in great shape but you might check that for any corrosion.

Could you be more specific, there is no such metal as "marine bronze".

[Nicholson58]

Originally Posted by boatpoker

Could you be more specific, there is no such metal as "marine bronze".

That is not exactly true. The term roughly refers to bronze alloys of less than X zinc and greater than X copper. To be fair, it is a goofy old time term referring to a family of marine corrosion resistant alloys. Variations are made based on the desired mechanical properties and end use.

https://www.copper.org/applications/...osion.html#top

https://www.avivametals.com/collections/naval-brass

[boatpoker]

Originally Posted by Nicholson58

That is not exactly true. The term roughly refers to bronze alloys of less than X zinc and greater than X copper. To be fair, it is a goofy old time term referring to a family of marine corrosion resistant alloys. Variations are made based on the desired mechanical properties and end use.

https://www.copper.org/applications/...osion.html#top

https://www.avivametals.com/collections/naval-brass

Actually I believe it is strictly true unless you can refer me to a specific listing for "marine bronze" rather than the general list of names for the many types of bronze used in marine applications such as "silicon bronze", "aluminum bronze", phosphor bronze" etc.

Inmy Certified Marine Corrosion Analyst courses I never heard of a "marine bronze" other than a few companies that have glommed onto that unofficial name for 85-5-5-5 bronze but thats marketing not metallurgy
.

PS. Your second link to "naval brass". "NA is actually a brass and is classed as such due to it's high zinc content. It is not a bronze at all.

[Vinton]

Hi All, and thank you for all this input - much appreciated. Final question: if (italics added...) the existing wood failed at some point in the future, would you think that replacing it with HDPE marine board could / would work in this kind of application (templating the existing rudder and cutting the HDPE into the template's shape and replacing...)?

[SwellGuy]

I wouldn't go slapping epoxy over that thing - it's like trying to dam a river with some saran wrap.

If you truly encapsulated it with a completely watertight resin, even at the rudderstock, even at the gudgeons, that's one thing, but a boatyard special is certainly going to have places where water can get in. It'll expand, crack your epoxy/fiberglass, and allow more water in. That superficial coat will keep it wet when you haul out and i'm betting it'll just speed up any rotting. It'll also hide actual problems (big checks/splits opening up, etc.)

If anything, have someone qualified add some bronze drifts perpendicular to the grain. Long skinny bolts that aren't bolted tight to allow for expansion of the wood when it's in the water. This can give you certainty that it won't split along the grain, although I'm betting now that brought this up you'll find that there are already enough of those in there to make you feel warm + fuzzy.

[Vinton]

OK, and thanks for that. I've learned to cover it up would not be a good idea from all these replies, so I will not do that. Much appreciated. The rudder is actually, currently in good shape. I'll continue to inspect things as closely as my inexperience / experience will take me. Thanks again.