Stuck swing keel

[qbot2]

Hi All, This question is regarding removing rust and freeing rusted components, so I am unsure if this is a topic that you cover. I have looked in FAQs and not found any clues. As background, I have a sailing boat (Hunter Sonata if that helps) with a swing keel mechanism. Basically, the swing keel is a large block of cast iron (1200mm horizontal/front to back x 400mm horizontal/side to side x 250mm vertical), with a slot (900mm x 300mm x 40mm). Imagine this (pictures are much easier!) being bolted to the underside of the boat, with the long (900mm) slot on the bottom, and open (300mm vertical x 40mm horizontal) to the rear. A 1200mm x 300mm x 38mm cast iron blade pivots on a 25mm dia bolt (at the closed end or front of the keel), and swings from horizontal (up or housed) to vertical (down or vertical) under its' own weight for sailing. The chap I have just bought the boat from said that the keel has been in it's UP position for about 3 years, afloat in a marina.
I now have the challenge of freeing off and removing the blade. So far I have cleared loose flakes of rust and debris from the slot with a pressure washer, removed the pivot bolt, attatched a winch to the rear of the blade to give a constant tension, used various hacksaw blades, improvised chisels and thin strips of steel to chip away at the rust build up between the blade and the slot. The blade has moved about 40mm with approx 9 hours work so far. I am just wondering if there are any tips or techniques you have, for ways to dissolve or remove the rust? I know that a number of products are available as 'Rust Remover', but I am not sure if they would penetrate the depth of rust in the slot or if the 'coating' some of them form on top of rust would jam the blade in further? Any Ideas? With the size of the keel block and the fact that the boat is fibreglass, I have not tried using heat...
Thankyou for taking the time to read this, if you got this far!, and I apologise for giving so much background, but I do not know what YOU know.
Thankyou again,
Austin Holden

 

[Guest]

I know that my first thought would be to call Hunter ... why shouldn't they know best?

Humperdinck

Email: HJ@Seacracker.org
Website: www.seacracker.org

 

[claymore]

Try a very large steel crowbar and a longshafted 28lb hammer. slot the bar down from the top inside and give it a clout. I'd be tempted to put the pivot bolt back in first as you'll end up having a hell of a job re-locating it all. Think about putting a centreboard in a dinghy then increase the difficulty by a factor of 27.

regards
Claymore

 

[jamesjermain]

I had one of these many years ago and the keel was always getting jammed. However, in our case it was due to mud accretion because she was on a drying mooring. I am surprised you have this problem with rust because the clearance, at least on mine, was sufficient to allow for many years rusting before causing problems.

The problem with the Sonata keel is that you cannot get to it from inside the boat. I had a baulk of timber which I used to lever the keel down. I inserted it between the top of the keel and the hull at the after end where it came clear of the stub keel and heaved. The timber was slightly soft and had no sharp edges or corners, but clearly, care had to be taken not to exert too much force or the gel-coat would be damaged.

I suspect this treatment may not work in your case. Have you tried hanging a heavy weight off the tip and leaving it?

There may be a rust treatment which will work but I don't know of one.

Avoid like the plague rust stabilising solutions which will certainly make the situation worse.

I think you are right to remove the pin. The chances are that it will be quite severely corroded and will need replacing.

Do get in touch with Hunter who are helpful and knowledgable (tel: 01702 541015).

JJ

 

[Guest]

I have been thinking about this................
It seems that you have tried the obvious ways with little success and now is the time for a change!.

I suggest a mechanical approach once you have doused the whole thing with a can of WD40 equivalent overnight.

The winch applying constant pressure will keep moving what is already moving but it is unlikely to start the movement off - which is what you need. Equally it is unlikely to apply the sort of mechanical advantage/leverage that you need. I do think that it is along the right lines.

If you can apply the winch does this mean that there is a [small] hole through the keel at its rear [deepest] bit - there often is. If so wire it up and apply a slide hammer or an improvised equivalent with some REAL weight on it as you need to really shock the keel into movement just like a pile driver in reverse.
Alternatively start thinking about how an hydraulic jack or ram might be used if the GRP keel were suitably protected with wood.
If there is a way of gripping the keel then wire it to a ring in the solid ground/concrete block etc and get the yard to crane your yacht up with the slings close to the keel slot for support.
If there is no obvious way of getting a solid grip on the keel then maybe you might have to get your drill out and make one. If any of the above work then you won't mind putting a bit of epoxy back in a small hole.

Hope something works - let us know the result

Best wishes

Andrew

 

[qbot2]

Hi all, thanks for your advice, I am using a penetrating oil and time, combined with the winch, a 5' bar and a hammer. This just seems to be one of those jobs that will take as long as it takes...
Cheers,
Austin Holden