Rudder Post Drip Cure ... success !

[fmueller]

On my CD 27 Jerezana I've always had a certain amount of dripping (especially under power, only very occasionally under sail) from the top of rudder tube, just below the tiller cap/strap. I've read in other posts here that this is "quite common" and "just an annoyance". What it does mean is that I am always tracking seawater into the cabin with my shoes and the mainsheet is more or less permanently damp, or even soaked.

This past spring the dripping slowly stopped. When I hauled midsummer I had quite a bit of growth, especially barnacles on my prop, but also a little colony inside the rounded seem between the upper rudder and the deadwood at the back of the keel. This got me thinking if I could disrupt the flow of water up that seem (which sort of forms an angled sluice from the prop aperture aimed at the post) I could stop the dripping.

(edit: I should have left the barnacles in that seem)

Since there is a little ragged clearance there in the glass work at the top of the rudder (you can see about 1/2" of the actual post) I decided to wrap a piece of line around the rudder post to see if it would help.

I should have taken a picture. I used a short length of 1/4" braided line. I simply tied it with a double reef knot, then applied a little heat with a propane lighter to kind of solidify the knot. It does not impede or bind the swing of the rudder until just before the point of hard stop to port and starboard, and even then I can push the last little bit to that hard stop point, port or starboard. I typically never swing the tiller that hard anyway. Since I was bottom painting, I gooped up this little "collar" just for the heck of it.

Well, so far, no dripping, under power, or sail. None!

Time will tell how long the line stays in place, but I don't see why it would wear from friction. It's Dacron, so it should not rot. Maybe yearly it gets replaced.

[John Stone]

On my CD 27 Jerezana I've always had a certain amount of dripping (especially under power, only very occasionally under sail) from the top of rudder tube, just below the tiller cap/strap. I've read in other posts here that this is "quite common" and "just an annoyance". What it does mean is that I am always tracking seawater into the cabin with my shoes and the mainsheet is more or less permanently damp, or even soaked.

This past spring the dripping slowly stopped. When I hauled midsummer I had quite a bit of growth, especially barnacles on my prop, but also a little colony inside the rounded seem between the upper rudder and the deadwood at the back of the keel. This got me thinking if I could disrupt the flow of water up that seem (which sort of forms an angled sluice from the prop aperture aimed at the post) I could stop the dripping.

Since there is a little ragged clearance there in the glass work at the top of the rudder (you can see about 1/2" of the actual post) I decided to wrap a piece of line around the rudder post to see if it would help.

I should have taken a picture. I used a short length of 1/4" braided line. I simply tied it with a double reef knot, then applied a little heat with a propane lighter to kind of solidify the knot. It does not impede or bind the swing of the rudder until just before the point of hard stop to port and starboard, and even then I can push the last little bit to that hard stop point, port or starboard. I typically never swing the tiller that hard anyway. Since I was bottom painting, I gooped up this little "collar" just for the heck of it.

Well, so far, no dripping, under power, or sail. None!

Time will tell how long the line stays in place, but I don't see why it would wear from friction. It's Dacron, so it should not rot. Maybe yearly it gets replaced.

Fred, can you post a picture?

[fmueller]

John,

I didn't take a shot ... actually had low confidence this would work - but it seems to be.

Here is a sketch ... I think the space between the upper rudder (concave) and the deadwood (convex) acts like a little channel and puts a stream of pressure riright up against where the post enters the underside of the hull. In the small Cape Dorys there is no seal per se. Just a plastic bearing I believe. So the water column in there must just be pressured upwards. Maybe the "rope collar" disrupts the flow just enough.

Its pretty irregular up there between the hull and the rudder ... not sure there would be the same gap on all boats due to mfg tolerances ... I could only just get this little piece of rope in there. I had considered screwing a silver dollar right at the aft upper underside of the aperture which would partly block prop wash from channeling up that gap. Sounds silly, but what the heck.

Fred

[Jim Walsh]

Very innovative approach, essentially some packing where there is no stuffing box to limit water intrusion. I like it.

[John Stone]

John,

I didn't take a shot ... actually had low confidence this would work - but it seems to be.

Here is a sketch ... I think the space between the upper rudder (concave) and the deadwood (convex) acts like a little channel and puts a stream of pressure riright up against where the post enters the underside of the hull. In the small Cape Dorys there is no seal per se. Just a plastic bearing I believe. So the water column in there must just be pressured upwards. Maybe the "rope collar" disrupts the flow just enough.

Its pretty irregular up there between the hull and the rudder ... not sure there would be the same gap on all boats due to mfg tolerances ... I could only just get this little piece of rope in there. I had considered screwing a silver dollar right at the aft upper underside of the aperture which would partly block prop wash from channeling up that gap. Sounds silly, but what the heck.

Fred

Very interesting and innovative Fred. Glad it's working.

[jbenagh]

Very clever solution!
Jeff

[Sailingscotland]

Brilliant….I have a CD28 with the same problem. Mine also stopped before lift out. Once cleaned and anti fouled, the water was back! Next lift out I will try the braid as you did. Well done. Hope it works on our boat.

Regards

[fmueller]

Follow up ... three day trip NANTUCKET to Rhode Island YC . Not a drop so far.

Cheers

[sgbernd]

Great idea. I will have to give it a try. And I think your approach is correct, break the strength of the flow so the water can't make it up the tube at all.
Thanks for posting this.

Steve Bernd

[sgbernd]

Since Valhalla is on the hard right now, this is a good time to try the fix. My idea is to use an o-ring, the diameter matched to the rudder shaft which is 1 1/8" in my case. I will snip the o-ring diagonally, fit it around the shaft, then use contact cement to glue it back together. I tried this at home and the glued joint is pretty strong.

Since there is no UV, and no load on the o ring, other than water pressure, and growth isn't fond of rubber, hopefully this will serve the same purpose. As I've a lot of motoring to coming up to get her home, a good test is upcoming.

I will report back with results.

Steve

[sgbernd]

My CD28, Valhalla, just motored from Ensenada to Ventura arriving yesterday, after roughly 50hrs of engine time, with dry cockpit sole!

I used the o-ring around the rudder shaft, which if I were to do again, I would recommend getting an o ring of slightly larger i.d. than the rudder shaft o.d. because the rudder shaft has a bit of paint, resin, and crud which expands the o.d. a bit from the metal diameter.

Thanks so much for following this one thru and posting the results. This is a significant improvement and for those contemplating the modification, another report of sucess.

Steve Bernd

[fmueller]

That’s great Steve. My repair is still holding. I’m just not getting and water at all. Next time I haul I’ll revisit this thread.