Common rudder fracture - left to corrode

[skiziks33]

Hi
I'm new to the forum, and so very pleased to finally have this group to share and learn from. So... ahoy from Canada!

On to pressing matters. The rudder on my new (to me) Marieholm was cracked open at the top pintle, which is commonly remedied by installing an extended SS brace. However, the previous owner allowed the boat to sit with this opening in the rudder and time has led to severe corrosion. Any suggestion how I can salvage this rudder?? Otherwise I will shape a new rudder from wood. A quickish fix would be ok too, so that I can go sailing and leave the new rudder building for the winter months.

rudder corrosion.jpg (57.19 KiB) Visad 51570 gånger

Cheers!
Justin

[johan swe-1870]

Welcome to the forum!

Oh dear, your rudder do look in a very bad state indeed.

I wasn't aware of there being steel inside the rudder. And what an irritating choice of material!

I put on longer stainless side plates on my IF-boat rudder many years ago, before the rudder had any crack. Although I then drilled new bolt holes further down, I am not sure what is inside my rudder. I don't remember the drill took any metal out.

Can it be that the rudder production has varied between the years, the boat models or countries? As your boat is in Canada, was the rudder perhaps locally made in USA or Canada?

I am not sure; were all IF-boats and Marieholm 26 made in Sweden and then exported, or were some made abroad?

How old is your boat?

[skiziks33]

Johan

My boat is an M26 built in Sweden in 1978. I am quite sure that all the rudders have a steel frame. It is a common design to fabricate a rudder with an SS insert and foam body. Here are some pictures of another much less severe repair.

I thought I might build it up with epoxy filler and layers of wetted out fiberglass. Sand it down, paint it and reinstall the pintle. Then have the new SS plates made to extend well below the repair, remount the rudder and go sailing. Any thoughts on this approach? How can I clean up the steel? I have never worked with metal, but Is there a way spot welding what's left? Is there a something I can apply to the steel to protect it from further corrosion before adding epoxy?

Roder_slipat.jpg (149.67 KiB) Visad 51495 gånger

MOTORF~1.jpg (135.09 KiB) Visad 51496 gånger

[johan swe-1870]

Yes, it is common to repair or reinforce the rudder by mounting longer plates at the top. I did that myself just to prevent any crack. Here is my boat:


I can't really see from your last two pictures that there is steel INSIDE the rudder.

In your situation I would try to clean the rust as much as possible and build up new glassfibre with polyester. On the both sides I would put such extended SS plates as in the pictures above.

To clean the rust off I think you can use a steel brush or have it sand blasted. Welding I'm sorry I don't know.

[maja]

It will perhapse be a good idea to buy a brand new rudder, especcialy if you regard time as money... ...

In the pricelist of http://www.marieholmboat.se/ you will find

Rudder without fittnings IFE, M-26/261 SEK 12.350:-, which is corresponding to about 1.500 US dollars. i.e in the same price level as for a new mainsail...

Perhaps an interesting price, even though the cost for overseas transport is to be added..

[skiziks33]

Thanks for the help
Maja. I can buy a new rudder??? That is amazing. I would prefer this.

I will look into this and reply back here with an update

Thanks!

[skiziks33]

Well. No response from Marieholm Marina about ordering a new rudder.
I think I'm going to just remove all the corroded steel and patch the section with epoxy resin and filler. Then I'll add the new extended 316 SS tiller bracket. This will get me sailing, and perhaps this winter I will shape a new rudder from wood.

Any thoughts?

[johan swe-1870]

That will be fine I think. Maybe you will find that your repair will even last longer than this year.

The Marieholm Strömstad Marina may take some time to answer. Try to call them instead!

There is also a used rudder for sale at our marketplace http://www.ifboat.com/index.php?q=salutorg , check the item "Roder".

[skiziks33]

Thanks fellas. I'll let you know how the repair goes.

[Fredrik IF-1011]

I see that you added a picture of my rudder, which is an M26 rudder with a steel core. I used an angle grinder to remove the rust and then used GRP to build up the rudder again. As I have understood, there are different types of rudders for IFs and for M26s. In my case the steel was in pretty good shape, so I didn't need to take strength into consideration. But I believe that a solution with epoxy and glass fibre would give enough strength.

[skiziks33]

I have would have done this work already, but my studies have kept me away from the boat.

This is a good thing, because you suggest using fibers. After establishing that I would use epoxy for the repair, I read something somewhere that advised against using cloth. I wish I could remember where that advice was given and the rationalization that followed, but I cannot. Perhaps wrapping wetted sheets around a build up of epoxy and filler would add the appropriate strength. Any further thoughts on why using cloth came to mind for you?

I can't remember where I found the images of your rudder but they've been very helpful, so thanks!!

[maja]

When using epoxi, you have to use special glass fibre mats/cloth. They will advise you in the boat equipment shop.

[skiziks33]

Any reason, specifically pertaining to this repair, that might make cloth a poor choice? Im simply considering two options

Both begin with grinding down the corroded steel, spraying on rust protection inhibitor/lubricant, followed by an epoxy primer for steel
then either I...

1. use resin and filler to fill and shape the open rudder cavity, followed by new prime and paint with the rest of the rudder
OR
2. resin and filler in the cavity, followed by a wrap/shell of wetted out cloth, which lays up against the existing rudder. then followed by new prime and paint with the rest of the rudder

Both repairs with be completed with new 316 stainless steel tiller brackets that extend approximately 10 cm beyond the repair site

Any thoughts as to which repair option is better?

J

[johan swe-1870]

In my opnion you should use no 2 with many glass fibre mats carefully wetted with polyester or epoxi. The attachment to the existing rudder body should be grinded off to a several degree on both sides, so it not just forms a right angle connection to the cavity.

With just filler in the cavity there will be nothing else than the steel plates to transfer the forces. Filler just fill, nothing else, and will break under load.

[Fredrik IF-1011]

Basically, I agree with Johan.

Before I realized that there was a steel core in my rudder, I was adviced to grind down the area around the crack so that the angle was something like 10:1 in order to get maximal adhesion to the plastic/steel and in order to distribute the forces to a larger surface. You should use cloth, as many layers as possible, as the cloth/epoxi together will replace the steel core. The filler should only be used to give a nice and even surface for the paint. Filler doesn't give any strength at all.