Wet Rudder

[wooslehunter]

I spotted a couple of rust coloured spots on the bottom of my rudder & suspected water ingress.

Now it's in the garage with a few small holes drilled in the bottom & has leaked water for the past couple of months. So, I intend to bring it in the warm with a few more holes drilled top & bottom.

After a couple of months in the warm I'll strip the paint, plug the holes with epoxy filler & replair any other holes I see, followed by epoxy paint.

Any recommendeations for the epoxy paint?

Any comments on the treatment?

 

[RivalRedwing]

others will probably be along in due course with the details... a lot of rudder ingress issues are due to failure of the seal between the stock and the blade. The only fix that seems to make sense is to grind out a trough and epoxy in a couple of o-rings. When I dried out a rudder I also cut some inspection holes to inspect the tangs and used epoxy resin (not paint) as a sealant. I asked questions before starting so a search of the forum will reveal the earlier threads

 

[wooslehunter]

Thanks for the o-ring trick. I haven't ground out around the shaft yet but am intending to do so. I'm sure water's getting there.

 

[Robin]

Do you know what is inside the rudder? A lot of them are foam filled and the foam can actually dissolve into a gungy mess. The cure is to split the blade, replace the filling and put it back together again with a layer or two of mat to close the joins, this also allows proper inspection of any internal metal tangs. Alternatively cut a sizable access hole in one side and do it that way, laying it back up and fairing in afterwards. Pretty well all rudder blades leak through the shaft entry and the 'O' ring is probably the best prevention but even that IMO is not perfect.

 

[Chris_Robb]

I have seen a screw in tap (V small)fitted on one boat. In the winter when the boat is ashore, the tap is left opened to allow water to drain out - especially in freezing weather which I suppose could split the rudder.

 

[Guardamar]

Rudder

My boat came with a bung in the bottom of it, and it had soaking foam inside, not very uncouraging that would not dry out. I drilled lots of 2" holes sufficiently large to scoop out the foam in most places, which let it dry out and partially inspect the tangs, and then glassed and faired over the holes.

With hindsight, I would split the rudder if possible, scoop out all foam and put in the O ring as Robin suggested - I just filled the rudder / stock join with epoxy filler.

The bung is still there, and shows it leaks very little after a each year in the water. Ultimately I would like to make a new thinner, deeper rudder - one for the project list.

And another vote for epoxy resin rather than a paint for first coat at least

 

[Bosun Higgs]

Only one of the 4 big boats I have owned has had dry rudders. All the others were wet.

 

[Dipper]

Since you have the rudder off and in your garage I'd be very tempted to open it up and check the tang welds. My rudder is hollow and it used to hold a lot of water. When my tang welds failed (I'd just cast off from my mooring) I removed my rudder and cut an access hole to repair them. At the same time I used a modified O ring method to seal the stock. My GRP was very thin so I glassed in two thick PVC bushes to take three O rings each. You can see the details here (scroll down a bit). At my last survey the rudder was dry so it works.

Thanks to Old Salt Oz for the O ring idea.

 

[SHUG]

Since you have the rudder off and in your garage I'd be very tempted to open it up and check the tang welds..

Wow ...that looks like a LOT of work but I suppose there aren't any shortcuts. How long did it take to do the job?

 

[SAMYL]

I'm afraid the O-ring ploy is not as good as it would at first appear.

You will get a good seal between the O-ring and the shaft because the ring will be tight on the shaft but there will be no pressure between the encasing glass fibre/epoxy/whatever to effect a seal there - so water will flow in past the O-ring on the side next the epoxy. Epoxy/glass fibre does not stick well to stainless (most rudder stocks) so the seal will eventually fail.

The best solution is to use something that will stick to the rudder stock and the material of the rudder blade creating a permanent seal.

Sikaflex may be suitable but I would suggest CT 1 as it sticks to just about anything, even when it is wet, and is recommended for use underwater. It can be painted over when dry.

 

[Dipper]

Wow ...that looks like a LOT of work but I suppose there aren't any shortcuts. How long did it take to do the job?

It took me most of the winter but that was probably 98% thinking time and 2% actually doing something. It was the first time I'd used epoxy so I did a lot of research to see how best to do it. I was surprised to find how little information there was on the internet regarding rudder repairs which is why I took photos as I progressed.

The tangs were welded by a professional and the PVC bushes were made by a friend on his lathe. If I had known what I was doing, I could probably have completed the job in 2 - 3 days.

 

[oldsaltoz]

Back when I started using 'O' rings to seal rudder stocks I used 2 rings pushed together, I now use 3, this ensures the middle 'O' ring is fully protected on both sides.

Field testing has also shown that some brands / types of rings stick to epoxy better than others, so I would advise you to test the adhesion to epoxy whan deciding on the 'O' ring type.

Just lay the desires ring on a single layer of resin overnight and try to pull if off after curing, 'some' types will peel away, others will be destroyed in the attempt. These are the ones to use as the bonding will be more waterproof.

Good luck and fair winds. for 2012.

 

[oldsaltoz]

The total time will depend on conditions when the work is done, and how long it will to dry out at the start.

After the effects of the above work on 3 to 5 days and note not all will full days, more time is spent waiting for applied epoxy to cure than actaual work time.

Tips:
Wash down with Acetone before you start any sanding to avoid spreading and contaminants.

Epoxy resins can leave a layer of residue after curing, it can be rinsed off with water, start at the top with a slow running hose and rub with a kitchen plastic scourer (Scochbrite) till the water no longer forms beads on the surface, it only takes a moment to remove.

Use a scale to measure the mix of resin and hardener.

Humidity can and will cause problems, I start mixing after 10 AM and mix my last batch at 2:30 PM, 73% humidity or less for best results.

Use latex gloves and rut two gloves on each hand, you can then peel and carry on if things get a bit sticky.

Always use a threaded roller and roll out as much resin as possible, this will add strength, reduce weight and total cost.

Good luck and fair winds.