Drilling a rudder weep hole

[Nom De Guerre]

My Hunter 28.5 has the original Foss foam rudder. When I purchased, the surveyor noted higher than normal moisture readings in some areas of the rudder, and indicated that I may have to rebuild/replace it sometime in the next 5 years.

I'd like to extend that time by as much as I can and want to prevent the freeze/thaw cycle from doing any damage while she's on the hard over the winter. I've decided to drill a weep hole in the rudder now to see if I can drain any moisture out before the freeze, and will just fill the hole back in with epoxy before launching in the spring.

Has anybody done this with a foam-cored rudder and noted any real success? Do you think that a single weep hole at the lowest point is sufficient, or should I drill one at the leading and one at the trailing edge? If I know there is moisture higher up would it help to drill a hole at that level or will all moisture eventually drip down to the bottom anyway? What size hole do you recommend or did you find was adequate? A 1/8" hole? A 1/4" hole? Something even bigger?

Educate me, if you please.

 

[Sanfelice]

I drill about 6 holes every year I pull out of the water. Mostly along the bottom since gravity will slowly drain the water. Some times I attach a shop vac to the holes and try and suck water out. Been doing this for 15 years. In the spring, I inject epoxy into the holes, sand and paint. Most Foss rudders of this era will have water in them. Since you are on fresh water I wouldn't be too concerned about the internals of the rudder rusting out.

 

[Caboteur]

Weep

Hi,
If it is easy to take down the rudder, take it off and bring it somewhere it won't freeze. Set it up side down and let it drip through the rudder post joint.
In the spring just seal up the rudder to rudder post joint. Repeat yearly or as needed.
Pierre

 

[Nom De Guerre]

Hi,
I drill about 6 holes every year I pull out of the water. Mostly along the bottom since gravity will slowly drain the water. Some times I attach a shop vac to the holes and try and suck water out. Been doing this for 15 years. In the spring, I inject epoxy into the holes, sand and paint. Most Foss rudders of this era will have water in them. Since you are on fresh water I wouldn't be too concerned about the internals of the rudder rusting out.

I suppose I'll plan to drill more than just two if you find that six isn't unreasonable. Do you recall how big in diameter you drilled them?

Hi,
If it is easy to take down the rudder, take it off and bring it somewhere it won't freeze. Set it up side down and let it drip through the rudder post joint.
In the spring just seal up the rudder to rudder post joint. Repeat yearly or as needed.
Pierre

Unfortunately it isn't easy to remove the rudder while on the hard.

I'm limited to drill/drain/fill as my plan for now.


Thank you for your suggestions.

 

[31seahorse]

Has anyone suggested a garboard plug for the job? Just like in the stern of one of those boats that don't have a mast. It seems to me that one large hole well placed would do the job. That would also eliminate the drill - drain - plug the hole routine.

Respectfully, 31seahorse

 

[Robert 47]

The PO replaced the rudder on our 87 Hunter 31 for just the reasons stated here in this thread. The fact that it is a funky design, and made cheezy as well. Over the years I have read many threads regarding this problem here on this web site. In my opinion, this should be your number "1" improvement on any sail boat with a foam rudder. The after market rudder improves the handling of our boat on any point of sail. We have wheel stearing and you can litterally let go of the wheel and the boat will stay on course for a long way. You can even turn the boat on "a dime" so to speak as well. Of course, we do sail on a river so you can't go to far! If interested fire me off an email, and I will look through our papers and give you the manuf. of our rudder.

 

[Chris Patterson]

I bought a boat on the hill last year, and it had a foam rudder. A survey done ten years ago noted water intrusion in the rudder. The boat sat on the hill for three years, with a hole in the bottom, (probably about 3/8"), and I took it off the boat to rebuild it. When I put pressure on the sides of it, water ran out. I was amazed. Now don't let this discourage you, this boat may have been "swamped" for several years, but to retain water that long? Wow. I'm thinking, that foam retains moisture for a very long time. I guess.
Regardless, we have a plan here on the yard to eliminate that problem. It is done frequently, is not very cheap, but solves the problem. And yes, it involves copious amounts of epoxy..

I guess the minds that are greater than mine have a very compelling reason to use foam, response time on the helm or something. But foam rudders do not seem to be the answer.

 

[Sanfelice]

Size

I usually drill 1/4 in. holes.

 

[Warren Milberg]

I've got an '86 H28.5 with the Foss Foam rudder. Every other year, I drill two 1/4" holes on each side of the rudder as low down and forward as I can. I fill the holes with epoxy putty each spring prior to launch. I've only noticed a very small amount of water coming out of these weep holes.

 

[Gunni]

Speaking of water-logged Hunter rudders...I was walking the yard last spring and noticed a recently hauled, larger Hunter (maybe a 41') and there was a stream of rusty water weeping just above the ballast bulb. On closer inspection I rapped the keel fin and realized that it is a hollow fiberglass molding. It had water inside. Apparently Hunter hung the ballast bulb on an internal steel strut. Weird.

 

[Navicula]

I drilled two holes in mine........one on each side.......it dripped for 4 months, while on the hard...I epoxied the holes afterwards..

I had a moisture survey done on the hull and the rudder this year because i did an epoxy bottom job ........the surveyor told me not to be alarmed when we get to the rudder because the readings are always higher because of the foam...

someday you could rebuild it
or you could replace it with a new foam rudder
or you could have a custom made one out of aluminum......

 

[Nom De Guerre]

An update; I drilled a couple of 1/4" holes on the bottom edge, and three per side (one down low, two higher up at the bottom of some hollow-sounding areas). A few CCs of water came out of a couple of the holes.

Interestingly, when I slapped the hollow-sounding areas, I could see more water droplets getting blown out.

In any event, I obviously have some shrinking of the foam core/delamination from the FG skin happening, in addition to the water intrusion. I plan to deal with it all as follows:

- drop the rudder enough to get at the shaft/rudder interface, and rehab the joint seal (likely with SIKA, maybe 291).
-inject a low-e closed cell foam into the drilled holes where the voids are. Great Stuff Window and Door is a polyurethane that seems to have the properties I'm looking for at cheapskate's price-point.
-fill the remainder of the holes with epoxy resin/filler mix.
-touch up with paint.
-repeat the drill n fill in a few years.

Happy to take additional thoughts/suggestions.

 

[kito]

At first I thought plugging all your holes except the lowest one and the highest. Insert a air compressor nozzle the high one and seal it and run low pressure air to blow the remaining water out the bottom and help dry. But....it my cause even more delamination so never mind

 

[tommays]

One of the better things I did was use a dremel to make a good size gap were the post enters the rudder

And then use gflex epoxy to seal it as I have had very good luck with gflex in areas of high motion as it can flex much more without losing its bond or cracking

 

[alexco38]

I installed (screw and glue with 3m4200) a 3/16 SS flat on the bottom and tapped 2 x 1/4" threaded holes. In the fall, I just remove the 1/4" SS bolt to let the water out. Two holes because one will suck in air.

In the spring, I put the bolts back with a nylon washer. Like a oil drain plug of an outboard motor.

Usually about 1/2 to 1 litter water come out and drip for a few hours after that.

Been 7 years.

 

[DannyS]

This is a summary of my rudder repair from a couple of years ago.
http://forums.oday.sailboatowners.com/showthread.php?p=744783&highlight=rudder delamination

 

[Nom De Guerre]

I moved forward with the foam injection yesterday. I drilled a few more holes the same size as the nozzle on the Great Stuff, and then injected foam into each hole, moving to another hole only after letting foam flow out of adjacent holes for a few moments.

What were cavities, seem to be no longer. There is now little to no difference in tapping sound between untouched and injected areas.

Next up will be to epoxy the holes in the skins - but that needs to await the next warm day (it's cooling down until next week, unfortunately).

 

[Nom De Guerre]

And, have now epoxied the holes, cleaned up the surgery, and top coated with bottom paint. She's in the water and the rudder is at least as good as I found it, hopefully better.

I'll update with any additional findings after I haul in the fall.

Thanks for tagging along!