keel on steel eventide

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keel on steel eventide

Postby edgray1 » Mon April 24th, 2006, 11:32 am

Hi John et al,
the restoration of Arabesque a 27' steel Eventide is now underway. I have stripped out the interior to get a good look at what neglect can do.
There will be more work than originally planned but that seems to always be the case.
I'm doing a flow chart to best utlise my resorces. The first major project involves the keel. Under the ply floor is a mess of concrete with steel punchings as aggregate. There has been at least 2 pourings the 2nd of which is spread almost to the chine. On the outside underneath the keel is a chunk of lead 9' long 6"or so wide and 5" deep. This is good ballast but I have read that galvanic errosion is a serious worry. Also from inside there is no evidence of bolts so I wonder what is keeping the whole show in place. Sika flex?
The questions I have are, do I cut the keel off the boat after removing the concrete overlaying it, fabricate a replacement, weld it back to the frames and plating and pour the lead into it? Probably the best solution but a tricky excersise I should think. Or maybe it would be possible to remove the lead then encapsulate it in steel or epoxy then refasten it to the existing keel also a bit tricky? Keeping the whole thing straight and just the sheer weight are just 2 problems that I will have to overcome any comments would be greatfully recieved.
Regards Eddie.
PS I look forward to another instalment from Rachel Moore, hows it comming along and what are u doing for ballast?

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putty and paint

Postby edgray1 » Tue April 25th, 2006, 6:26 am

Further to my balast keel saga.
This morning I jacked the arabesque off the tyres where she has been sitting after the crane lifted her from the float. She now is sitting on some blocks straight and level with a temporary plastic carport over her. I can now get under her for a good inspection and the 'lead' keel, a source of anxiety for some time, turns out to be concrete :oops:. putty and paint makes things what they a'int.
This, for me, is both great news and a dilemma. Great news in that the thought of replacing the keel is was the stuff of sleepless nights but the concrete with its lack of weight probably goes some way to explaining the performance.
I am planning to replace the leaky timber cabin top with 3mm steel and also lengthen it to take in the front hatch this will add weight above so I will be requiring extra down low. I can calculate the weight of steel and fittings but am not sure how to interpret the results to know how much ballast is required where. any help? regards Eddie

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Fiddler's Green
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Postby Fiddler's Green » Wed April 26th, 2006, 9:16 am

The ballast on my boat is 1800lb external on the keel, plus extra internal lead weights to make it up to 2240lb or 1 ton. My boat weighs in at 3.5 ton, so the ballast is less than 1/3rd of her displacement, which is considered light by many... she is 27ft long and the hull is thicker than standard, 15mm instead of 12mm.

I would imagine you would need a Ton and more, to get the same sort of fraction of ballast to total weight. She weighs over 4 Ton I think you said....

I built the cabin forward to the plan option, as I thought it better to have the space inside than on deck, and I've been proved right too. I have 5'8" headroom inside the hatch square!

The cockpit seat level is higher than the drawings, as I raised the hull and cabin sided 5" to allow me more headroom without it looking like a shed on top, which is what happens when the cabin sides are raised only... The seats are at the right height so I can sit and see over the cabin top... I can sit on the top of the coamings too, to see better! The coamings are 4 to 6 " wide. the idea was to make the inner side straight so I could hinge locker lids on it, and the outside curved to follow the hull more, it works too. It also means water does not come over into the cockpit if a wave comes on deck aft...

hope this helps,

Proud owner and builder of 'Fiddler's Green'

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Postby ironmaiden » Wed April 26th, 2006, 10:16 am

Hi there Eddie,
with regard to your ballast problem I dont think I would be happy with the fact that the concrete and punchings are coming up to the chine level.

I would start to be concerned that with the wieght of the ballast being so high up in the boat will comprimise the boat in a knock down (she might not self right).

It would appear from what you are saying that there has been a bit of a ballasting problem with the boat.
the best solution if you are prepaired to do the work would be to remove all of the concrete ballast and start again.....not as daunting as you may think just hard work !!
arm yourself with a big rotery hammer drill (and ear defenders) get the whole thing back to bare metel, you will find that the steel will be in good condition if the concrete was well stuck to it.

when you have done this you have two options you can weld up any bolt holes and make water tight the keel then add all lead ballast internally, this will keep the ballast as low in the boat as possible where it sould be, seal the lead ingots in place with cement, you can then plate over the ballast to seal it in place.

however going on what you say In your post I think I would be tempted to remove the conrete as above then providing the keel side plating is in good condition burn or grind off the keel bottom plate, this will allow you to extend the plate floor sections down through the open keel bottom,you can then add on the the extra 5 or 6 inches to the draft that was there in way of the concrete slab.

plate the keel bottom with 12 mm steel taking the profile from the bottom of the new extended floor sections using a hardboard or thin timber pattern, tack the new bottom in place, then plate the extended keel sides again using a template. then fully weld up the whole thing.
carefull preperation of cutting and welding will do a neat job.

you can then re-ballast the boat internally, if for any reason you carn't use lead for ballast then you could always extend the depth of the keel even further, this would allow you to use concrete and steel punchings again but keeping the ballast low in the boat, also this may have to be your option if you are going to add more weight topside by increasing the cabin lenght.

I hope this has been some help to you, good luck with your project.

Regards Rachel Moore.

PS I will be using mainly lead but also steel punchings and cement for my ballast.
Last edited by ironmaiden on Wed April 26th, 2006, 7:10 pm, edited 1 time in total.
don't shout "starboard" just shout "steel".....then everyone gets out of your way !!

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Postby ironmaiden » Wed April 26th, 2006, 12:34 pm

just thought I would add a note about pouring lead into the keel in one go I would not recomend this as there are a few things to take into account;
if the keel is heated to quickly as would be the case, it could cause the steel to expand too rapidly as a whole, and any welds that are not of good quality may fracture (hair line cracks) which may become a real pain trying to put right. you may get away with it but I think that casting ingots of a handlable size would be the better option, at the very least you could distort the shape of the keel if the plating is not very thick.

regards Rachel.
don't shout "starboard" just shout "steel".....then everyone gets out of your way !!

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Joined: Tue April 11th, 2006, 10:21 am
Location: mullumbimby NSW

Postby edgray1 » Fri April 28th, 2006, 12:54 am

G'day Rachel, thats my best Aussie welcome
thanks for input. I suffer from a bit of tunnel vision when confronted with a problem only seeing my solution which inevitably is difficult and costly. You are right in suggesting that to remove the offending concrete is the go. though it will be a task. I had a little bash at it yesterday to see what might be involved and it is a very sturdy mix and no mistake.
I exagerated a little when saying that it was up to the chine I'll see if I can send you a pic. The filling in the keel proper is probably ok it is encased in 10mm of steel and the punching content looks high at least what can be seen. its the stuff that has been added later that is giving me grief as the steel encasing it is only 3 mm and corrosion near the edge could be dangerous as there is localised pitting evident. I will take your advise and get rid of it so I can see how much plating needs replacing.
As for the concrete lump on the bottom of the Keel (maskerading as lead)

I should explain this. Craig, the guy I bought it from told me there was 350kgs of lead under it. I did'nt check it I just thought it a strange practise. He had never seen it as he bought the boat from a South African who was living on board using it as a cheap caravan type of temporary accomadation. The SA guy was being deported the next day for over staying a tourist visa and offered it at bargain price. It had been slipped, bogged and painted a few months before with photos of its underneith wich shows a lumpy addition attached to the keel. It looks like a badly cast something and he believed it was lead as told. I'll never know weather the SA was pulling a fast one but my guess is that 350 ks of lead is worth some thing as scrap so that would influence the the value if the rest was a dud. The lump was painted and I hadn't, dug through the paint to see what it was untill a few days ago whilst looking for attachments that I still havent found. what amazes me is why any one would make such a mess of casting a simple shape in an easy to handle medium as concrete.

I'll remove it and replace it with?
I was led to believe that lead not poured defeats its expense as the voids decrease its mass to the level of steel. any thoughts?
I am thinking along the lines of 5 or 6, 6"x1" flat bars flame cut to match the bottom keel profile, laminated together and welded to the keel. would this be strong enough or would it need to be strapped as well?
Hows your project coming along?

I guess your weather is starting to warm
Regards Eddie

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