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  #11 (permalink)  
Old 05-15-2009
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Those railroad rails certainly complicate matters.

Is it possible that the original owner/builder put too large of a rig on the boat?
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Old 05-15-2009
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Quote:
Originally Posted by bluetommy77 View Post
Thanks for the quick responses.

The issue with removing some of the original concrete is that there were railroad rails embedded (the previous owner says welded to other framework in the concrete) in the concrete ballast, and they are supporting the engine mounts. I'd like to find an alternative to jackhammering out the concrete under the engine and under the 90 gallon stainless fuel tank.
Damn, that complicates things a bit.

Quote:
I'm taking a stability class for the new Canadian 150 ton master's ticket and took one a few years ago--but am trying to remember the terms, so please bear with me:

1) wouldn't putting more ballast up higher be less effective than less ballast down lower? The righting arm is the difference between the metacentric height and the centre of gravity, is that sounding about accurate? The longer the righting arm (gm?), the stiffer the boat, the snappier the motion (and also... more uncomfortable at sea!).

So maybe more ballast in the bilge will help me carry a bit more sail, and yet enjoy a slower roll period and more comfy ride. We're just over on our ear... with reefed main and jib in 15 knots (like burying the caprail 1/2 the time--and Cecil Lange told me they should never bury their rail in conditions like that).

2) 4.8 cubic feet of lead doesn't sound like a lot... but how much is that spread over a width of 4 inches and a length of say... 120 inches? Would that make my shoe only 2 inches deep, and spread the weight that is hanging in the fiberglass out effectively? 4 cubic feet--when I think about a cubic yard of way, way, way less dense gravel or even concrete... isn't that almost the size of a dump truck load?
A cubic yard is 27 cubic feet... way more than you need... four cubic feet would be a section 12' long x 2' wide x 2 inches thick...

Quote:
3) sail choice has a lot to do with it, but still--having to go from a high cut yankee to stays'l and 2ble reefed main in 15 knots and only getting 5 knots for being over... 15 degrees or more... that's unreasonable. That really says "more ballast" to me. When we're offshore and shorthanded and in a larger steeper swell on a murky night with a surprise squall... that degree of tenderness has "knock down" written all over it. The boat doesn't loose control or round up horribly, but it's still asking for trouble.
Yup...need more ballast...

Quote:
4) thanks for the reminder on the fumes. molding lead into steel buckets with a tiger torch? I heard it took hours. Anyone had experience with sand molds? A friend of mine molded some lead in a pig trough. so I guess the steel has a much higher melting point than the lead
Yes, you can make some decent molds for lead out of sand. Lead has a melting point of about 620˚F... Iron has a melting point of about 2800˚F. Silicon Dioxide has a melting point of about 3000˚F.... so you have lots of ways of making the molds for the ingots.

Quote:
5) thoughts on piercing the hull with bolts, then sealing and glassing over? Just doesn't sound like a good thing if we ever grounded and had to loose the shoe, but could come through otherwise intact... it may not be so clean with bolts tearing holes in the keel
First, the hull may not be able to support the shoe.... since it wasn't designed for the extra weight. The damage the loss of the shoe could cause is really not something I'd want to consider in a hard grounding. Also, adding additional ballast is going to increase your draft as it is... adding it externally penalizes you twice for the additional ballast—once from its weight, and once from its thickness.

Quote:
6) absolutely a priority to retain keel foil shape... such as it is. Cecil Lange told me his keels were beautiful and did provide some lift, so it's true I don't want to mess with the beauty.

Anyway, appreciate the thoughts. This is a fun, old school project and I hope to keep enough brain cells intact from the melting process to enjoy some safe and fun offshore cruising!
Keep us posted and let us know how it goes.
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Old 05-15-2009
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Think Blister, Mister!

Why not template the keel at the base and have Mars cast a couple of blisters (a tear-drop shape split along the center-line and milled to the template) that you can bolt to either side of the keel with bolts through the blisters/keel just above the base. With the yacht trued up you should be able to bore 4 holes through the transverse axis of the keel to epoxy four 1/2" dia mounting bolts in place over which the blisters would mount on either side in counter-sunk mounting holes with a layer of bedding compound on the bearing faces of the blisters. Once the nuts are locked down, the counter bores can be fillted with epoxy fairing compound and the whole business painted.

Been there, done that, got the T-Shirt. Not hard and not unduly costly.

FWIW...
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Old 05-26-2009
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I have about 800 lbs of lead pigs on top of the concrete keel cap in my OS33 Cheoy Lee. It does wonders for stability and seakindliness. It takes 20 kts wind on a taught bowline to get the cap rail in the drink.

I suggest buying commercial pigs and using chembolts to bolt them into your concrete. Chembolts are anchor bolts with a glass tube of some horrible goo that is probably toxic and radioactive, but which stay put forever. As with anchor bolts, you drill a hole for the bolt, but then you put the glass tube in the hole, and drive in the bolt, which has a mixing head on it. This mixes and activates the goo, and once is sets (in minutes), will never come out - so in the event you turn turtle, the lead will not fall on your head.

Also, if you paint the lead gold, like I did, you can tell little kids that there is pirate treasure under the sole.

Best Regards,

e

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Old 05-27-2009
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I too have the lead pigs for trimming reasons in my boat, but my "tenderness" issues have more to do with a light load and improperly placed water tanks hanging from the side decks. Breaking those into 4 x 50 gallon tanks, converting an empty 40 gallon SS tank below the engine into a working diesel "day tank" (post-filtration) and moving 4 x 150 lb. 8D AGMs under the saloon floor just aft of the mast will, I suspect, aid matters. I also suspect I will be reducing or losing those lead pigs.

My point? Think of where your tankage is before you go altering the boat. The difference between me sailing with empty tanks and full is significant.
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Old 05-29-2009
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here is a thought. if you have access to the top of the concrete you could core drill a hole down in to the crete. a core driller does not use impact, it uses diamond bits, that will cut steel. you could drill a bunch of 4 inch holes down about a foot in to the concrete, then cast a lead slug inside of some 4 inch steel pipe, then epoxy the slugs in. the casting would be easy enough to do at home due to size, being only about a gallon per tube. the core drilling would take a better part of a day but it could be done while the lead is melting.

a real poor mans way of getting lead would be to go to a gun range and get permission to collect the lead from the back stops. they would probably let you get it for the scrap price, or maybe free, but you will have a bunch of brass to remove from the molten lead
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Old 05-29-2009
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Think the best option is to place the lead as low as possible to take advantage of the leverage. 100lbs three feet away from the center of rotation will have the same effect as 300lbs one foot away. So going through the side of the keel and boring a few holes into the concrete would allow you to get the weight where you need it with the least overall effort. That way you could also chip out as much concrete as possible, then replace it with lead in resin where you can't get nice clean easily cast and filled forms cut.

Most effective would be to leave steel, and only replace concrete, steel is nearly 500lbs per cubic foot, while concrete is about 150 per. Lead is around 700lbs. So if you replace concrete you're gaining 550lbs for each cubic foot, but only 200 with the steel.

The absolute best way would be to chip out the crete and steel, then replace with lead. Concrete chips out pretty easily if you first make a hole. The bigger Bosch hammer drills have a hammer only setting that will eat concrete in no time.


Only ballast info I found on the Cape george is for the 34 which says there are three 3000 pound pigs bedded in lead shot and resin.

Find out where the lead is, then concentrate on replacing as much of the rest as you can. Most stud finders work by detecting density differences, so you should be able to mark out where the existing lead is, a magnet suspended from a string will show where steel is when it's close enough to the surface (works to about 2" depending on magnet the longer the string, the more sensitive it is) exploratory drilling will show where the concrete starts if everything else fails.

Ken.
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Old 07-15-2009
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Just wondering if you've made any headway? I'm curious what Cecil recommended? Also, you might try talking with Todd at Cape George Marine Works. What ever you do, it seems important to get the weight in the right place. I'm finishing a CG 38 which has the ballest low and below the fuel/water tanks. I would need to tear the boat apart to get to the ballest area. I think, with proper design, a through bolted solution would be the direction I would head.

Bill
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Old 07-28-2009
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Hi,

I replaced the concrete ballast with lead in a much smaller boat and here is what I did. I still have the boat and the change was a real improvement. I did a few other things, too.

The boat is a Rhodes 22. it has a centerboard / shoal keel. I was "playing" at re building this boat and gutted the interior. Replaced the bulkhead that supported the deck mounted mast with a SS compression post that I fastened to the new lead ballast in the shoal keel. The former concrete ballast was encapsulated, I am guessing poured in from the top. I opened it from both the top and the sides. I demolished the concrete and replaced it with lead bars I cast myself. I had been given the keel from a salvaged Stonehorse and had plenty of lead. I used 4" angle iron to make a mold that was approximately as long as the space where the concrete had originally been. I simply cut the angle iron to length and welded square a plate on each end. This gave my mold ends that allowed it to sit level. My biggest problem was cutting chunks of lead from the keel that would fit into the mold. CAUTION! Handling and heating lead exposes you to a very toxic environment so read up on safety precautions and protect yourself properly. This was a real DIY project. I heated the lead in the mold and added pieces until the mold was full. I used a propane heater like the ones you can buy to flame the weeds along your driveway. It was enclosed in some bricks and I did all of this outside well away from any sources of ignition. I don't remember how many of these triangular ingots I made but they stacked very tightly in the space I had created in the keel. I did do some rough calculations and figured that the old concrete plus the stuff I had gutted from the interior of the boat equaled the weight of the lead I added. As I placed the ingots in the keel I set them in an epoxy / micro balloon paste.

The boat is still in use today. Its pretense of being some kind of pocket cruiser is gone now. I retained the V- birth. I also added a layer of 1/2" Airex to the inside of the hull to 6" above the waterline and pumped two part marine foam into every nook I could find. I reinforced the hull/ deck joint by glassing it with an 8" triax tape in epoxy and ss bolts.

This is an interesting boat. It has a flared hull to give it deck space for the standing rig. It is very dry. It is really a dinghy that was stretched. I sail it in the very strong currents of Passamaquoddy Bay and the waters around Eastport, ME. With no deep keel and lots of low ballast it copes with the currents very well. I added the Airex after hitting a submerged RR tie one beautiful September evening.

The lead replacement went well. I did not have to cope with keel bolts since the skin of shallow keel was part of the hull.

Good luck

Last edited by downeast450; 07-28-2009 at 12:18 PM.
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Old 07-28-2009
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A quick and dirty way to get rid of concrete is to pick up some phosphoric acid, (greenhouse supply in most areas) pour that on the concrete and it will start to bubble and turn the concrete into water and sand. Afterwards removal can be done with a wet vac.

Ken.
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