Weeping Rudder Repair

[Wyatt]

This is my first real post.
Let me start by thanking all the contributors of this fine board for helping ease my path.
Hopefully imagevenue, the host I have chosen will be acceptable.
Here goes...

During an end of season inspection I noted cracks along the leading edge of my rudder.
After talking with the builder and previous owner it became apparent that the rudder has a history of collecting water.

Last week I took a cabinet scraper to the rudder and removed all the bottom paint so I could more closely evaluate the damage. Clearly there have been previous repairs to the leading edge in Toy Boxes [a 27' Precision sloop] 20 year history.

The spade rudder is 2 halves FRP skin, PU foam core bonded together with polyester putty and has a stainless hollow tube post with an unknown type of flange welded to it...in other words, a typical spade rudder on an Edson radial wheeled steering system.

I would pull the rudder and follow Don Casey's advice on repair except Toybox also has a Raymarine 5000ST autopilot. Removing the rudder post in this circumstance is so complicated with the autopilot that I want to try a permanent fix without removing the rudder post.

In a sentence, my permanent fix strategy is: repair the delamination, glass the leading and bottom edge, epoxy barrier coat the entire rudder, caulk the rudder post where it enters the rudder and bottom paint.

Here are some pictures:
Leading edge. Note color differences that indicate previous cracks/repairs the entire length.



Delamination area Closeup:



Percussion soundings on port side with findings marked:



Percussion soundings on starboard side with findings marked:
The 3/16" holes in the bottom confirmed that the foam core was still damp after 7 months.
I set a fan under the rudder and ran it 14 hrs for the last 3 days and will continue til work starts.



Details of cracks noted on bottom...before holes and kerfs made:



Rudder post and delrin ring @ entrance:



This is the short scope of work:
Prep damaged area in accordance with answers to Burning Questions below
1. Use colloidal epoxy to repair the delamination on the port side.
2. Use microballon and/or colloidal to fill and fair cracks and holes
3. Use 4" 6oz fiberglass tape to glass the leading edge and bottom.
4. Drop rudder several inches to gain access to rudder post and rudder top.
5. Prep and sand rudder post and rudder top.
6. Epoxy barrier coat rudder top-4 coats
7. Caulk rudder post to rudder top.
8. 80 grit prep and bottom paint rudder top
9. Reinstall rudder
10. Epoxy barrier coat sides and bottom of rudder-4 coats
11. 80 grit prep and bottom paint rudder sides and bottom

Burning questions:
1. Research and common sense suggests the main entry point of water is the juncture of the rudder post and the rudder top, but sight evidence suggests water has gained entry along leading edge only. The job would be much easier if I only had to glass the leading edge, barrier coat and bottom paint. Dropping the rudder even a few inches means the possibility of loss of alignment in my steering system. I need historical advice please.

2. A test clamp of the mobile area of the port side indicated that debris inside the rudder will need to be removed before I can loosely clamp it fair. What would be the best manner of relieving some of that debris without causing more damage.

3. Should all the cracks [including the delaminated area ] be widened [V-groove with church key or other]? I like the ragged area @ the delamination...lots of fingers, but am concerned about the lack of surface area for the colloidal epoxy to anchor to.

4. I bought 3M 5200 fast cure for the caulk @ the rudder tube. My investigations since suggest that 3M 4000UV or Sikaflex-221[both polyurethanes] might produce a more flexible long lasting seal. Recommendations on caulk and prep in this area would be greatly appreciated.

5. I will be using West System products as they are most readily available, so detailed advice on procedures should preferably reference West's nominclature. [I have System 3's excellent The Epoxy Book too] The bottom paint is Interlux Micron CSC. I shop in Denver CO, so supplies and infrastructure found on the coasts are limited here.

6. I know I sometimes over ponder stuff. I strive for perfection. If you see I am being too anal feel free to set me straight.

Cheers and Thanks

[Weyalan]

Caveat: The information following is one single personal experience. It may not be repesenetative.

We had some issues with weeping in our rudder. Based on the pictures that you have posted, compared to your weeping, ours was very, very minor. When we sanded back all the anti-foul and paint to the original resin/glass, there were two or 3 very small holes that wept. We had the rudder inspected by both a repsected local shipwright and a repsected local builder who both said that this was not really any cause for concern. The shuipwright advised us to drill several small holes and blow warm air on the blade fro a few days to dry-out any moisture in the blade, then glass over and re-coat. When we drilled we did find several areas with wuite lot of water in the foam of the blade.

We ground back the obvious wet areas, filled, glassed and faired (epoxy resins throughout).

Approximately 3 months later, our rudder snapped in half, with the stainless steel shaft snapping clean through, inside the (stainless steel) blade. We were offshore at the time and the consequences of losing the rudder were "interesting" to say the least. Whether the water in the blade had any bearing on the failure of the shaft (anaerobic corrosion, maybe?), I couldn't say, but the reality is that short of very expensive non-invasive inspection techniques, there is no way of knowing the state of your rudder shaft inside the blade. Is this a risk you want to take?

[Cheechako]

There is a long post on this from a couple of years ago.... but: Leave the rudder in the boat. Cut a large rectangle out of one side with a skil saw. Pry it off and save it. (this is not as scary as it seems) Remove all the wet stuff in there and dry it out good. You can now inspect the situation well.In your case maybe you can inject a strong Epoxy mix in the cracked areas and clamp. Feather the mating edges of the rectangle and rudder and relaminate it back in. Fill and grind fair. In your case possibly add a couple of layers of Glass/epoxy around the whole rudder to strengthen and seal it? You can fill the whole rudder through a cored hole near the top if you want...maybe with light weight epoxy micro ballons mix ... repair the hole with glass/resin. This will avoid the possible corrosion to the shaft structure. You cannot get it dry blowing into holes..the water just condensates onto the glass! It's not that hard in the boat. If you remove it you might be better able to seal the rudderstock entry point easier upside down though. If you fill the whole rudder with resin/mcroballoons...well it probably wont matter if that seal isnt perfect!

[John A]

There is a strong posibility that the foam inside the rudder has become saturated with water and will need to be replaced.

[s/v Jedi]

I would first fix the crack, then do as Cheechako wrote.

Grind out that crack, not just a V-groove, I'm talking angle grinder. Wet it out (all with epoxy) and put a 2" wide glass-tape in the crack, wet that out while you push it a bit into the crack in the middle and then put a 2nd glass tape over that. Wet out, let it gel and fill it up for 90% with a colloidal silica thickened epoxy (peanut butter consistency). Let that cure for 24 hours and then cut out the square like in Cheechako's post. I would cut that out using an angle grinder with metal cutting disk and do this under a flat angle, creating extra surface for bonding it back later.

If you get some practice, you can fair all out with colloidal silica. I would not use micro balloons under the waterline.

ciao!
Nick.

[Wyatt]

Thanks for the prompt and thoughtful responses gentlemen.
Having seriously lurked on this board for several years I had hoped to see replies from the people represented in the thread so far.

Glad to see I was not over-reacting in my observations.

I've always wanted to become a better fiberglass mechanic. Looks like I get that opportunity.

I'll continue to update this thread with my progress.

[ggray]

I also have a leaking rudder with a ss pipe for the post.

Since the top of the post, while capped, is exposed to the weather, I can wonder if the water might come from rain.

Regardless, I want to get it out, especially when hauled for the winter. So what I did some years ago was to drill a couple of holes down low thru both walls of the pipe from the leading edge and then into the cavity behind. After draining and drying, I plugged the front holes. Now I can pump water out of the rudder with a little hand pump, even when afloat.

Perhaps this would be of interest to you.

[John A]

The medal parts that are internal to the rudder are not designed to withstand years immersed in water! Rudder failure will resute as the medal parts rust away.
Drilling a hole in the floor will not stop a leaky roof!

[Wyatt]

It is now clear to me that before I spend any time glassing and fairing, I need to remove a good sized portion of the frp skin and take a hard look at the health of the rudder post and flange.

Then I will really know if a rudder replacement is in my future.

[redhead78]

Something I found out the hard way, living in an area of extreme cold in the winter, was the rudder is in the water for at least 5 months, mine was also taking water. If it is at all possible remove the rudder and store in a garage or somewhere it can,t freeze. I repaired mine several times b-4 relizing the power of water freezing and thawing all winter. If you can remove it it will be easier to work on also...... Red

[s/v Jedi]

Originally Posted by Wyatt

It is now clear to me that before I spend any time glassing and fairing, I need to remove a good sized portion of the frp skin and take a hard look at the health of the rudder post and flange.

Then I will really know if a rudder replacement is in my future.

Correct. But take care that you don't cut it out so that the cracked area looses it's shape or falls apart. That is why I mentioned to fix that crack roughly before cutting a panel from the skin.

ciao!
Nick.