Repairing Rudder Balde Damage

[Martin Searle]

Folks,

I guess this one is for Brian or Steve S. but any advice welcome:

1 of my rudder blades has split along the join line, in fact its a perfect failure of the joint between the two halves of the blade the actual halves of blade have no damage, along virtually all of the leading edge of the blade just the top and bottom 3 inches unsplit. The trailing edge shows no signs of similar failure.

I have tried using epoxy resin to glue the joint but this fails after a month or so of use (not suprising due to the high stress that area of the blade is under).

I was wondering if my new plan:Tidy joint up by using a hacksaw blade to get rid of any uneven areas, put resin impregnated fibreglass matting into the split and then clamp, add more as required to fill the split thereafter, finally fairing off with Gelcoat filler compound would create a better permanent result?

How about 2 part expoxy glue?

This is not a new blade its the original one that came with the boat when I bought it 13yrs back.

Sailing with the blade after it failed on Saturday was an interesting experience since every couple of seconds the fibreglass would reach the point where it couldn't expand out anymore due to water rushing into the split and contract suddenly pushing out the water in the blade, the effect on steering was a sudden judder which meant holding a course was difficult and sailing with what is effectively a speed brake was a bit slow!. Needless to say I returned too shore toot sweet once I realised what had happend.

Martin S.

[George Stephen]

I guess that you need better advice than I can give, from Steve Sawford or Bryan Phipps.... but here's some thoughts.

At the Netley Nationals, one sailor was unlucky enough to suffer a failure in the glass fibre "plug" of his 2-piece mast (the "plug" is made in 2 halves that are joined together). He had recourse to steve Sawford, who tried but couldn't achieve a lasting repair "on the day". Steve reckoned the problem was that the glass fibre halves weren't dry enough.

I think you sail at Seasalter, so your rudder blade will not only proably be damp after splitting, but it will have salt there too!!! And the salt will prevent it drying out completely.

So whatever you do, I think you need to wash out the gap thoroughly with fresh water to remove any salt, and then dry it out - if you have an airing cupboard with a poorly insulated HW tank, this would probably help with the drying.

I'd guess the 2 rudder halves had been "glued" with glass fibre resin, but others, especially Bryan or Steve, will know better.

Opening the gap as you suggest may well help to get salt out and dry out the rudder, but it will leave the problem of glueing it back together without changing the rudder dimensions - if you were to clamp the halves, the rudder blade would become thinner......


George

[WaveyDavey]

I did a similar repair to one of my rudder blades last June and so far it has held up well.

In my case, the split ran from the tip of the rudder to approx 1/3 up the leading edge.

The repair I did sounds very much like what you have already tried. I took epoxy resin and, opening the crack gently with a screw driver, worked in as much as I could. I then gently clamped the two halves - hard enough to get good contact, but not so hard as to squeeze out all the resin.

One advantage I had is that I had just brought the boat, so the rudders had been unused a for some time and were 100% dry. As George has suggested perhaps the secret is moisture - or the lack of it.

You could try sluicing the rudder (and crack) with ample fresh water, and then dry it somewhere warm such as an airing cupboard for a week. Gently opening the crack a fraction during the drying process might help - maybe small wedges made from matchsticks with a craft knife would be suitable for this? Also position the rudders to dry with the drainage hole lowermost so any running water can escape.

Apologies if you have thought of and tried such things already.

[Martin Searle]

Chaps,

Thanks for your replies, I'll see what I can do with it.

The blade had been dry stored for about 8yrs prior to the latest repair attempt. I think the problem is that resin is just too brittle with no additional material in it to provide structural strength thus any weakness is ruthlessly exploited by the water and hence it goes bang, at least thats my theory.

I'll wash it out and then leave it too dry for a while and then effect my repair plan on it. The fibreglass tape should provide a more structural repair than resin alone. I'll gently file the edges a bit first to roughen them up to improve the bonding surface. In the meantime I'll borrow our club 15's port blade.

As a last resort I'll replace the blade, I previously did this for precisely this reason but having one nicked forced the re-use of the old blade.

Thanks,

Martin S.

[WaveyDavey]

8 years - that will have been pretty dry then

It sounds like I was lucky the split was lower down the blade and not too long.

Hope you're repair works out.

Cheers
David

[Robert]

I wonder if the repair is failing because most of the epoxy is soaking into the surface of the join? Perhaps a more "technical" solution using SP microfibres might retain sufficient epoxy at the surfaces to give an improved joint.

Just a thought.

http://marinestore.co.uk/page/mrst/PROD ... xy/HA1482/

Robert