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Old 08-05-2012, 19:10   #16
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Re: Removing Concrete Ballast

How old is the boat? If no problems yet and if it's one of those heavy built fiberglass dreadnaughts I doubt you'll have an issue. Quite a few boats were done that way.. it came from how they did a lot of fishing boats I guess. Many Rawson 30's were done that way. Never heard of an issue... and a lot of those are pretty old... back to the 60's...
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Old 08-05-2012, 19:27   #17
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Re: Removing Concrete Ballast

dreadnought is a well designed boat. is also a very stout world cruiser as it stands,so why ye wanna mess with it...you will only spend money and be totally unable to find lead.
epa said NO.
that is one of the reasons behind concrete keels inside of fg.
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Old 08-05-2012, 19:43   #18
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Re: Removing Concrete Ballast

what is a steel punching.....is that another English word?
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Old 08-05-2012, 19:49   #19
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Quote:
Originally Posted by Chief Engineer
what is a steel punching.....is that another English word?
It is what's left over when something has been cut (punched) out if plate steel. I have what looks like wing nuts mixed in with the concrete in my keel.
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Old 08-05-2012, 19:55   #20
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Like the centre hole out of a washer.
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Old 08-05-2012, 21:12   #21
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Re: Removing Concrete Ballast

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Originally Posted by dandreadnought View Post
sorry for not being clear. i was talking about stability under sail.

a big reason i think it is worth removing the concrete, is we are concerned the steel punching will rust and expand and cause a huge problem.

we just bought the boat and intend to entirely re do everything, and don't want to have to then go back and tear it apart later.
Heres my take on it without seeing the boat. The sails are years old-yes?. The chord on each sail has moved aft increasing drag and reducing lift. The baggier sails will make the boat heel a lot more than a newer flatter sail.

I would suggest going for another sail, in similar conditions, with lots of foot and luff tension with increased vang to flatten the sails and improve stability.

That will give you a good indication if the problem is just a sail problem and not the boat.

Ultimately, if the cloth is in reasonable condition, as sailmaker can re-cut and flatten them for you. They wont be any good for the americas cup, but certainly better than they are now.

If the steel punchings are in an airtight environment, generally they wont rust.
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Old 08-05-2012, 21:30   #22
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Re: Removing Concrete Ballast

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It is what's left over when something has been cut (punched) out if plate steel. I have what looks like wing nuts mixed in with the concrete in my keel.
Coachbolt.
we call that scrap/junk
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Old 09-05-2012, 05:23   #23
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Re: Removing Concrete Ballast

I've done that job on a steel boat that had been neglected for yonks (it was very cheap!). The ballast was lead under with a slurry of punchings above, the latter heavily rusted. It was more or less a full keel design, much like the dreadnought. It wasn't an especially difficult job, likely because the rust was so advanced. But the point is I HAD to do it.

But if your ballast appears dry and in otherwise good order, I'd say: "Don't do it Dan!". With that shallow keel, I doubt you'd derive the benefit you're after. All boats have different motions; since you're new to that boat, just sail it for a year or so to see if you adapt. And try out the numerous cheap ways you can alter your vessel (including suggestions above) to adjust that motion.

If you find it still simply doesn't suit, sell it and try another design rather than try to re-design the one you have. And most important, don't start pouring money into the boat until you've made that decision with the benefit of time on the water.

There's another member of CF with a Dreadnought 32; maybe contact him for discussion. His name's Butler: Cruisers & Sailing Forums - View Profile: Butler
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Old 09-05-2012, 08:26   #24
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Re: Removing Concrete Ballast

although a long time lurker on these forums, i feel i can add some first hand experience on this topic...

long story short, i removed the top foot or so of concrete ballast from my yorktown39. it sounds like a straight forward job but the reality is somewhere just short of mating elephants. first, the jack hammer is way too much tool, and can lead to delam of the fiberglass down the road, and just too difficult to finesse around the bilge. what you want to use is something more along the lines of an electric roto hammer. secondly, working below the level of your feet to chip out concrete/steel is a whole new level of misery, and the deeper you go the worse it gets. and just carrying buckets of rubble down the ladder gets to be a pain. i spent a total of 38 hours to chip out 1100lbs, the largest chunk of which was maybe the size of a walnut... and i only went down a foot.

im not familiar with the dreadnaughts scantlings, but changing the position/mass/lever arm of the ballast will have an effect on the load path through the glass at the turn of the bilge/floors/keel timbers. consulting with an na is always your first stop with such a project, imo.

as already noted, moving weight down and to the middle of the boat, taking your sail maker for a ride etc are all much easier places to start and likely to produce some results. reballasting would be the very last remedy id resort to.

seal up the bilge, i used glass/epoxy, repair any damage from groundings when it happens. if you must add lead as a last resort, glassing a shoe to the bottom/sides of the keel is relatively easy.

my .02
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Old 09-05-2012, 09:05   #25
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Re: Removing Concrete Ballast

Quote:
Originally Posted by Coachbolt61 View Post
It is what's left over when something has been cut (punched) out if plate steel. I have what looks like wing nuts mixed in with the concrete in my keel.
Coachbolt.

I've seen all sorts of interesting stuff tossed in the cement for ballast. I will never forget the Fuji 39 I repaired after a bad grounding. These boats are made in Japan, and apparently the cheapest form of ballast there was old pachinko balls(think pinballs). When I ground through the severe damage on the front of the keel, I was hit with a shower of thousands of rusty pachinko balls. Apparently they dumped the balls in the keel cavity first and poured cement over them, but the cement was too thick and didn't work its way down to the bottom foot or so of balls. That's a lot of pachinko balls in a full keel boat! The owner didn't want to deal with it, so we reblocked the boat stern down and shoveled all the pachinko balls back in the hole, followed by about 20 gallons of resin. You never know for sure what's in an encapsulated cement ballast keel, there are some strange examples. One of my coworkers had the same thing happen to him, but instead of pachinko balls that showered him it was ancient raw sewage! Stand from under if you cut through one of these for the first time, you don't want to be lying on your back under the keel when whatever is in there comes out, I've learned this the hard way.
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Old 09-05-2012, 16:42   #26
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Re: Removing Concrete Ballast

Ok, I've done this twice, contemplating a third time.

The first boat was a 32 foot cedar on oak cutter, which had a lead keel. But the owners wife at some point convinced him to add steel and cement to the bilge. Sadly he did this without tarring the bilge first and the lime in the cement ate the lignen from the oak, leaving the keel (to a depth of 2-3 inches), the floors (completely) and the bottom of 32 consecutive pairs of ribs in a fibrous mess.

I ended up chiseling the cement and tractor bits out of the bilge with a hand sledge and a star chisel in order not to completely destroy the remains. After it was done, I solidified the keep with West System epoxy, and soaked the floors in it as well. The ribs I repaired by splicing in 18inches of steam bent oak and then putting a 1x 1/8 stainless steel strap from keel to 30 inches up the rib and refastening with stainless steel machine screws and nuts.

I have no idea how it worked out as I ended up going bust and lost the boat.

2nd case was an H.O. 28, built of steel and the keel can was full boiler punchings cover with about 6 inches of cement and steel mix. This time I used a Kango electric jack hammer to bust up the mix. We then took out everything, including the water in the punchings and weighed everything as it went over the side in buckets.

Using the waterline as an arbitrary datum I calculated the moment arm of the steel and cement mix. From that I calculated the amount of lead needed right at the bottom of the keel can, and then acquired tire weights, smelted them into ingots and packed them in. That gave me enough room to install water tanks and a holding tank in the keel can above the lead.

Again, I have no idea what happened with the boat, I sold it to a retired school teacher and wasn't able to keep in touch.

My third boat, Sabre Dance has cement and punchings. I emailed Bruce Roberts-Goodson and asked if it was possible to remove a foot of keel off the bottom if I replaced it with lead. He concurred.

At the moment the cement and steel mix appears to be in good shape, I may or may not do so. However, I will keep the keel in its original shape as the boat is heavy and I am removing as much weight as I can. I will see how she floats later this year and go from there.

It is possible but its a bloody lot of work, and you need to take the changing moment arm of the ballast into account. I'll leave it to you to decide if it's worth it or not.
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Old 18-05-2012, 18:09   #27
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Re: Removing Concrete Ballast

Dan,
Just caught your posting and I hope you got my PM regarding the Bay Area owner who jack-hammered his polyester/boiler punchings out (less challenging than cement). He found that , as was reported in an old post on a different site (go to my profile page and check out the info and pics in the Dreadnought file) by his experience the ballast was extended too far fore and aft causing hobbyhorsing. After replacing the ballast with lead and concentrating it closer to the center of effort he reported the motion was improved.

Is there any indication of rusting/swelling?

How did you come to find that it is a cement keel?

This may be an idiotic question but how do you mean "too tender"?

Ketch, sloop or cutter?

What's your mast height?

What year was the boat built and who was the builder. Apparently there were two Dreadnought builders... the more active near Santa Barbara and another in San Diego.

Curious I am and eager to help however I can.
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Old 18-05-2012, 23:16   #28
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Re: Removing Concrete Ballast

As a follow up to my 5-7-12 post, here is the location of the mentioned items referring to both hobby horsing and removal of steel punchings as ballast:

Dreadnought 32 - Page 3 - SailNet Community
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Old 19-05-2012, 03:46   #29
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Re: Removing Concrete Ballast

Greetings and welcome aboard the CF, robwilk37.
Thanks for sharing your experience.
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Old 19-05-2012, 04:04   #30
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Re: Removing Concrete Ballast

If OP has never chased out concrete by hand I suggest practicing first on a concrete block.

Then re-evaluate how bad the boat is for you.
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