Are all GRP rudders full of water ?

[Guest]

And if they are should we be worrying about it ?

Mine has been ' weeping ' for about 3 months since hauling out and now seems to be on the last knockings.

I drilled a small hole in the bottom last week and the 'filling' seems to be of foam and feels fairly firm.

Do I just fill the gaps and think of Summer ?

Thanks for any suggestions that may be forthcoming.

 

[stretch33]

Both my previous boats were the same, l drilled holes in the latter for it to drain, left it in that state all winter. heating via radiator. Then l used some expanding foam filler inside it, capped the holes with pukka filler then epoxy coated whole rudder. Seemed okay following haul out, might just be luck though!

 

[brianhumber]

No. Most rudder stocks transfer the torque applied by the rudder/wheel into the rudder structure ie Blade, by welded 'tangs'
Being welded these are susceptable to rusting if imersed in sea water (because yards do not bother to heat treat afterwards properly). GRP rudders are normally moulded in two halves and then bonded together around the stock and tangs and filled with closed cell foam or left empty. The bonded joint is where water normally enters especially around the stock. The last yacht I had had this and when testing by turning the blade with the tiller fixed midships, slight movement could be felt. A new blade was moulded and on opening up the welded tangs had completely corroded away. Suggest you exaim yours with great care.

 

[pandroid]

I had a GRP rudder that weeped 'rusty' water (when I bought the boat the rudder had a crack in it) so I paid for the builder to build me another. He split the old shell in two and found that all the metallics were fine, and the 'rusty' water was the foam deterioriating. It took me three trips back to him before the new rudder (constructed on the old stock) fitted the boat.....

 

[oldsaltoz]

G’day Vic.
Most of the ‘expanding’ foam is not closed cell and will fall apart in water. Rebuilding a rudder is not difficult, cut and shape closed cell foam around the tangs, then glass the tangs and shaft to the foam, add some Q-Cells or Micro Balloons to fair it and glass over the whole thing. Tip, put a couple of ‘O’ rings on the rudder stock at the top of the rudder and glass them in. Also, consider putting some balance on, about 10 to 12% of the total rudder area in front of the shaft.

Avagoodweekend Old Salt Oz

 

[PeterGibbs]

It is a fact that many are waterlogged. Almost all rudders ill give a wetter meter reading than the hull. Water ingress through the stock apperture and along the sealed edges where the tho halves were glued together, is common.

By letting the moisture out you are doing the right thing. And you can expect drips to appear for a long while. Sealing up the holes is a must but not that easy, as you will find out. You need something that adheres to damp surfaces! And without attention to the ingress points, it will be with you again next time you haul out.

A surveyor will tell you that the rudder can be landed and split open, the filling replaced, the tangs checkout out etc and the whole shebbang glued together again, and this will cost you in considerable three figures.

However, as you can surmise, the world is not full of failed rudders. They are built with this eventuality in mind and will last quite some time. If there is the slightest inkling of movement rudder to stock then it IS time for serious treatment; otherwise, having been through all this myself, you can continue draining and working on the possible ingress points to slow down the deterioration.

PWG

 

[Chris_Stannard]

Friend of mine had this problem, in a Baltic 35. Thought it was okay until his rudder fell to bits in the overfalls off St Catherines durnig the Round the Island race. He said the tow from the lifeboat back to Yarmouth was one of the most uncomfortable trips he had ever had. I guess the motto is if in doubt get it fixed.

Incidentally my previous boat was 12 years old and showed no signs of this problem.

Chris Stannard

 

[jtwebb]

Do not ignore it. I have a Dehler 36 and the rudder was condemmed by the surveyor. A new one was obtained after a long saga from Dehler which is solid and should last. When the old one was pulled apart the foam had separated from the outer case and was therefore not contributing much to the strength. They can be rebuilt in wood etc. but that depends on the state of the internal stainless steel web. A Leisure 23SL I had many years ago split its rudder in 'the hurricane' and that was rebuilt with solid glass. I wonder if ignoring the known problem invalidates insurance?

J Webb