I recently bought a 1980 Prindle 16. First boat of any type that I have owned. Took it out immediately, and I loved it. I am hooked.

It's completely sailable, but it's a bit old and neglected, so I am going to be restoring it over the winter. I've already replaced the easy stuff, and now am into the rudder. From what I've read, the rudder seems to be the weak link on the Prindles The first thing I did was tear out everything and order replacement sheaves and lines. The rudders themselves have been patched up, sanded, and I'll soon by putting a nice shiny gel coat on them. The castings were in, well... not great shape. The castings were rather wide and bent. They were about 3/4" wider at the outside than the inside. I have since remedied this issue on the castings, sand blasted them, and powder coated them.

So here is the issue:
Years of these castings being out of spec has allowed the hole in the rudder that it pivots on to wear out. It's rather enlarged, and makes the rudder sloppy, and makes the release even more sensitive and hard to adjust correctly.

The plan:
I plan on drilling out the hole and pushing it back to 1/4" before I gel coat these things

The question:
What is inside the fiberglass of the rudders? I don't want to drill out the hole and sleeve it if there is nothing substantial behind the fiberglass I'll be removing, or at least, I'll need to think about it a bit more and possibly put a fanged bushing in there to distribute the load.

Thanks!
Brian


EDIT: I guess worst case I could just make some new, wooden rudders.



Edited by briantroberts on Aug 26, 2018 - 04:47 PM.

The typical repair here is to fill the hulls with epoxy (recommend JB Weld for this small of a project), and redrill them. The location is critical for correct operation of the hulls and the proper helm balance. You can shoot for the center of the old (larger) hole, or get a hold of a non-worn rudder to use as a template.

--
Bill Mattson
Prindle 19 "Gelli Bean"
Prindle 19 "Cat's Pajamas"
Nacra 5.2 (Will sail her a bit and let her name herself)
--

You have two rudders, use the best one as the template.

Completely fill the hole with this:
http://solarez.com/produc…rez-extreme-3-5-oz-tube/
It cures in minutes in sunlight and is really strong.
Use the other rudder as template and re-drill the hole.
Then repeat with the other.

Making new rudders is really difficult to do well.

--
Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
--

mattson

The typical repair here is to fill the hulls with epoxy (recommend JB Weld for this small of a project), and redrill them. The location is critical for correct operation of the hulls and the proper helm balance. You can shoot for the center of the old (larger) hole, or get a hold of a non-worn rudder to use as a template.

The more I looked around at general rudder repairs, I see that the epoxy route is common. I've got tons of different epoxies around the shop. This is probably what I'll do. Thanks!

klozhald

Making new rudders is really difficult to do well.

Just curious, but what would be difficult about it? I've got 2 to use as templates, seems like it would be pretty easy given the right tools.

If you are interested I have 2 new, never used Prindle rudders that I would be willing to sell

briantroberts

klozhald

Making new rudders is really difficult to do well.

Just curious, but what would be difficult about it? I've got 2 to use as templates, seems like it would be pretty easy given the right tools.

Getting the shaping correct. You must shape your core material correctly to allow the protective outer coat to finish the profile needed and be the right size to fit the casting. The shape of a rudder is not a simple as it looks, and the wrong profile will create cavitation and be difficult to trim for proper helm.

There are entire web sites dedicated to correctly shaping rudders, and the math involved.
https://www.researchgate.…d-rudders_fig1_259579387
https://www.sciencedirect…le/pii/S0029801816303134

Your nearly 40 year old "neglected" rudders are probably not prime templates. The original bottom edges had square corners fore and aft. Do they still? This is not the issue, though.

My point is if you spend the time, effort and money to build rudders from a worn, 40 year old template, you end up with a new copy of a worn 40 year old rudder. Look for a pristine rudder to copy. I admire your courage and energy. I'm just trying to help you spend it wisely.

--
Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
--

briantroberts

klozhald

Making new rudders is really difficult to do well.

Just curious, but what would be difficult about it? I've got 2 to use as templates, seems like it would be pretty easy given the right tools.

Getting the shaping correct. You must shape your core material correctly to allow the protective outer coat to finish the profile needed and be the right size to fit the casting. The shape of a rudder is not a simple as it looks, and the wrong profile will create cavitation and be difficult to trim for proper helm.

There are entire web sites dedicated to correctly shaping rudders, and the math involved.
https://www.researchgate.…d-rudders_fig1_259579387
https://www.sciencedirect…le/pii/S0029801816303134

Your nearly 40 year old "neglected" rudders are probably not prime templates. The original bottom edges had square corners fore and aft. Do they still? This is not the issue, though.

My point is if you spend the time, effort and money to build rudders from a worn, 40 year old template, you end up with a new copy of a worn 40 year old rudder. Look for a pristine rudder to copy. I admire your courage and energy. I'm just trying to help you spend it wisely.

--
Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
--

mattson

The typical repair here is to fill the hulls with epoxy (recommend JB Weld for this small of a project), and redrill them. The location is critical for correct operation of the hulls and the proper helm balance. You can shoot for the center of the old (larger) hole, or get a hold of a non-worn rudder to use as a template.

Been out of town without the password to the forum since I posted this. It's all screwed up.

Do not fill your hulls with epoxy. The weight will be outrageous and the boat will probably sink. Fill the HOLES in the rudders with epoxy. And the "correct operation of the hulls" should be "correct operation of the rudders".

I must have been drunk when I wrote that.

--
Bill Mattson
Prindle 19 "Gelli Bean"
Prindle 19 "Cat's Pajamas"
Nacra 5.2 (Will sail her a bit and let her name herself)
--