Rudder water

[PabloPicasso]

The spade rudder on my pals GRP 30footer (circa 1980)has some abrasion of the gel coat, likely from rubbing against its stern lines. The gel coat is worn away exposing the glass fibre matting along the trailing edge. He drilled a 6mm hole through the bottom edge as moisture readings were high and water did fair gush out!

So, what to do?

Allow to dry out, fill hole and apply gel coat to exposed area?

Cut a 'window' in the rudder side for further exploration of problems/cause? Any internal foam will be sodden and useless very likely. So this could be removed and replaced with closed cell expanding type.

Allow to dry, peel back anti-foul, apply an epoxy coating over the complete rudder, prime and anti foul, and hope this seals against further water ingress.

Ignore and Carry on as before?

Another awkwardness is that the rudder cannot be completely removed without lifting the boat again, and no crane is due until spring, so any work will have to be done in situ in the cold damp Winter. So another option may be to do very little this winter, and remove the rudder for home working at the end of next season

Opinions please? Anything obvious I've missed?View attachment 46715View attachment 46716

 

[Tranona]

See my response to your other post.

From the photos and description this looks like a candidate for a complete rebuild. In the category of "yes, it probably does matter".

 

[Avocet]

I certainly think it merits further investigation. My gut feeling is that it needs grinding back and drying out so the trailing edge can be re-built with epoxy and glass reinforcement. If I was doing that much work,I might be tempted to split it and do the whole lot. Although in my post on the other thread, I'm quite blase about water in my rudder, that's because it's an old-fashioned transom-hung rudder, so if any of the metal structure inside it failed, I wouldn't lose it altogether. The shaft might spin uselessly within it, but it wouldn't drop off and be lost. I have a couple of pad eyes on either side of the trailing edge so I can attach ropes to either side for emergency steering if necessary. This one's more vulnerable, I think.

 

[neilf39]

Can you dig a hole underneath so you can lower it far enough to get out?

 

[J Neeves]

Rudders are often made in 2 equal halves which are then epoxied together and the joint taped. I'd be inclined to grind off the 'edges' and see if you can split the 2 halves, you might be lucky and it split easily. Then use the halves to make molds or gouge out the foam reglue, refill with closed cell foam and re-tape (use more tape). To dry the existing foam will be, basically, impossible. You can do this with the yacht on the hard.

It depends on how far you need to 'lift' but it is possible to lift the yacht without a crane - needs a decent tower of pit props with jack at the top, decent supports to either side of the keel (to stop it falling over) and another jack to fit under the keel as you get higher. You need a lot of patience, some really good help (and some faith). We have done it, some of our help came from the yard and a mining engineer.

Jonathan

 

[oldsaltoz]

If you have ever lost a rudder at sea you would not be asking some of these questions.

Time to fix the problem that started when major builders put the supply of new rudders out to tender and opted for the cheaper end of the results.

If the ground she sitting is not bitumen or concrete. dig a hole deep enough to drop the shaft out.

see the results here:-
https://www.google.com.au/search?q=...hannel=sb&gfe_rd=cr&ei=sbVYVO3aMMqN8QeHp4DwCQ

Good luck and fair winds.

 

[PabloPicasso]

Ok so I need to do something. I don't think lifting the boat is an option, and digging a hole maybe heavy work, and perceived as obnoxious by the boatyard/club.

So we could split the rudder in situ, drop out the pintel (as there would be plenty of space with the rudder removed) and repair in the shed at home. Refitting the rudder could be done when the boats are lifted in next spring.

Is there a flaw in this plan?

 

[Dipper]

Seems a good plan but you may find the stock still needs a (smaller) hole dug to drop it out completely depending on how far down the rudder it goes.

Use the Oldsaltoz trick of sealing the entry point of the stock with glassed in O rings whilst you are at it. This is where most water enters rudders. I've done this and can confirm that it works.

 

[Dipper]

I should also add that if you can sneak the rudder into the house when you rebuild it, the epoxy cures much more quickly than in a cold shed. It's not easy hiding a rudder though.

 

[J Neeves]

Your plan has merit but I think you will find the steel work will be too 'low' to drop it out (even without the rudder on). If you do it at home you will have both the time and environment to get it right so go for it! You can also take it down to the yard and check for fit.

There might be a reason why not but once you have the 2 new halves I actually cannot see why you cannot reattach to the stock as is, which means you would not need to drop it anyway. Though you might want to look at the bearings whilst you are at it.

When you re-attach I'd suggest heavier duty tape for the joint, ours seemed to be not much better than glass tissue, and if the rudder touches anything unforgiving its the joint that splits first (or seems to me).

Glassed in 'O' rings, good idea, never thought of that And something like Sika, as well?

Good luck

Jonathan

 

[oldsaltoz]

Seems a good plan but you may find the stock still needs a (smaller) hole dug to drop it out completely depending on how far down the rudder it goes.

Use the Oldsaltoz trick of sealing the entry point of the stock with glassed in O rings whilst you are at it. This is where most water enters rudders. I've done this and can confirm that it works.

Glad you found the tip useful Dipper. I have yet to have one fail so all good, perhaps I should patent it?

Good luck and fair winds.

 

[oldsaltoz]

Glassed in 'O' rings, good idea, never thought of that And something like Sika, as well?
Jonathan

Hello Jonathan,
I would never use Sikaflex for this application. The idea is ti entrap the 'O' rings but still leave them free to maintain a seal on the rudder stock under the glass.

It's important not to get any Vaseline (or other lubricant) used on the rings left on any part of the stock or you will actually create a path. so a good clean up after slipping them into position is critical.
I have been experimenting with Silicon tape to hold them and the lubricant in position with good results.

Good luck and fair winds.

 

[J Neeves]

I hoping not to need to know - but I'll steer clear of Sika et al - thanks!

Someone once mentioned that greasing rudder bearings is a recipe for abrasion as grit will adhere to the grease.

Jonathan

 

[oldsaltoz]

You will need to keep the temperature and humidity under control of the epoxy will not cure or worse not work at all and you have have remove a sticky mess.

If you not done this before and you do remove the rudder ti gain some climate control, essential by the way.

You could simply cut the glass cover off with a standard angle grinder.

Leaving the edges in tact for the moment. Start about the middle of the stock at the top a few inches down from the exposed steel and follow this line till you think you have reached the bottom of the stock but not run out of rudder.

Then cut towards the back of the rudder and leave about 5 inches between the cut and the trailing edge, then back up the top and across to the starting point.

This section will be stuck (or should be) to the rudder tangs that should be welded and gusseted on the stock.
Lifting the edges of the cut will indicate the areas still fixed. simply grind these spots as before so you end up with a cut all the way round a few holes cut around the fixing pints. At this stage you should be able to lever the first side off.

Now you can easily remove any sodden foam completely and see if you need to remove the other side, most often this not required, and the repairs can be completed and the section you removed can be re used.

If you decide to add the 'O' rings to the stock, do it after most of the repair is completed and the resin has cured so everything is solid.

This method can save time and money and reduce fairing time as well.

Note:
It is important that the contact between the tangs and the outer skin are correct. many rudders fail because they rely on the foam to maintain the alignment. If you replace the foam and still have gap between the tang and the outer skin, simply cut a hole or holes depending on the distance and distribution of load/support in the foam in line with the tang and fill it with a mix or epoxy resin and micro fibres (NOT balloons).

Good luck and fair winds.

 

[Neil_Y]

I hoping not to need to know - but I'll steer clear of Sika et al - thanks!

Someone once mentioned that greasing rudder bearings is a recipe for abrasion as grit will adhere to the grease.

Jonathan

Water lubricated bearings are best left water lubricated or check with the bearing manufacturer. we use some high pressure water proof grease that has been developed by the bearing manufacturer for the purpose when the bearing is also a thrust ring supporting the weight of the rudder.

New composites have lubricants within the composite to keep friction low and prevent wear on the shaft.

 

[PabloPicasso]

Removing the rudder. I could try and tip the boat so she goes nose-down. ANY ADVICE on how to do this safely, as there is no chance of a crane. She's in a good quality adjustable cradle. I don't think digging a hole will be an option

 

[duncanmack]

Removing the rudder. I could try and tip the boat so she goes nose-down. ANY ADVICE on how to do this safely, as there is no chance of a crane. She's in a good quality adjustable cradle. I don't think digging a hole will be an option

Borrow or hire 2 railway jacks (google for what they are). Lift and pack each side an inch (whatever) at a time. Lift the whole boat and cradle by whatever amount you want. When done, lower by a reverse of the lifting.
You will need lots of bits of wood, but it isn't difficult (any 10 yo can do it *) and is very safe if you take care as you go.

*10 yo + 10 ton truck + 5ton bottle jack + bits of wood = 4 ft elevation and a severe bollocking from grandfather whose truck it was. He did comment that it was a good idea tho' to chock the truck wheels to prevent it rolling off when the "job" commenced.

 

[PabloPicasso]

Use the Oldsaltoz trick of sealing the entry point of the stock with glassed in O rings whilst you are at it. This is where most water enters rudders. I've done this and can confirm that it works.

Would glossing in butyl tape work as effectively, or perhaps better than, O rings? Butyl tape would not perish as it remains flexible. Any thoughts on butyl tape in this application?

 

[doug748]

"Ignore and Carry on as before?"



That is what I would do. I tipped a 2ton, long keel, boat once, using an hydraulic jack under the keel. It is not to be taken lightly, I would rather dig the big hole.

If there is no play in the rudder/stock the chances of it dropping off next season are bearable to slim, unless your pal is thinking of an offshore trip. Next winter it could be done at leisure.

If it is a worry you could cut in a couple of windows (as outlined above) and check out the welding of the tangs, shutting up the holes with mat. The problem with trying to split the thing in situ is that you could end up with a right buggeration of bits, with the stock still trapped in the boat.

 

[PabloPicasso]

"Ignore and Carry on as before?"



That is what I would do. I tipped a 2ton, long keel, boat once, using an hydraulic jack under the keel. It is not to be taken lightly, I would rather dig the big hole.

If there is no play in the rudder/stock the chances of it dropping off next season are bearable to slim, unless your pal is thinking of an offshore trip. Next winter it could be done at leisure.

If it is a worry you could cut in a couple of windows (as outlined above) and check out the welding of the tangs, shutting up the holes with mat. The problem with trying to split the thing in situ is that you could end up with a right buggeration of bits, with the stock still trapped in the boat.

Ok, given all the variables, opportunities for cock-ups, and likelihood of being worse off with a nudged repair or worse, I'll recommend to the skipper to await the next lift out, remove the rudder then and repair in the heat and warmth of a workshop.

Thanks for all the input, it has helped with the decision making.