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post #1 of 8 Old 04-05-2008 Thread Starter
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Adding Ballast

When the ballast was poured into our full keel back in 1978 they didn't get it quite right. She sits about 2 inches higher at the stern than the bow. We're in the process of replacing our engine with one that is around 100 pounds lighter, which might make the problem even more noticable.

While the engine is out I'm considering adding some ballast to the very stern end of our bilge. Has anyone done anything like this? Any suggestions on how to figure out the correct amount? I would imagine I would fiberglass in some lead pigs?

Any advice appreciated. Thanks.
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post #2 of 8 Old 04-05-2008
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Is the boat actually loaded with your gear yet?

You may want to hold off a bit before adding ballast, because things like BBQ grills, full fuel tanks, and otherwise loading the boat - if you load center and aft, will definitely bring your stern lower. When I was cruising on my C-27 - the stern dropped a inch or 2 - and it didn't really take that much...If it is really a concern use something you can remove like sand bags or water jugs...

The stern really doesn't have to be weighted down too much to get it to squat right..but fiberglassing in lead - you may regret it later... some re-positioning of gear / storage items may make the difference you are looking for...

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post #3 of 8 Old 04-05-2008
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Year, make, and model?

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post #4 of 8 Old 04-05-2008
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Also, how many crew do you typically sail with? If you usually have 2-3 or more adults in the cockpit, that will often balance it out pretty well on a small-medium size boat. If you are talking about a 40+ footer then crew weight might not be as noticeable.

Another question, are you carrying a large inventory of anchor chain in the bow?


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post #5 of 8 Old 04-05-2008 Thread Starter
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It's a '78 Pacific Seacraft Mariah 31. I'm told it was the very last Mark I, but had the ballast poured the way they did it for the Mark II, which had some slight design changes. I'll certainly see what I can do about packing some gear a little differently. Using something removable is also a great idea, remove the possibility of regrets. We don't have an enormous amount of chain, but we do have 2 anchors right out on the bowsprit (35lbs and 20lbs). We only have the 2 of us as crew.

Thanks for the replies.
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post #6 of 8 Old 04-06-2008
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Sorry, Dhornsey, I'd forgotten that you have a Mariah.

I wouldn't call that an inordinate amount of anchor weight on the rollers (we have a 35 lb and 25 lb anchor on ours.) And if you aren't carrying all chain rodes, then anchor and chain weight wouldn't be contributing much to the bow-down trim. And two average adults in the cockpit probably won't correct it either.

Interesting about the ballast change between the Mark 1 and 2 Mariah. Good to know. Do you know whether your boat was factory finished or built out by an owner from a hull/deck kit?

Sometime in the past year or so, there was an interesting article in Good Old Boat magazine by Jerry Montgomery, in which he described ballast modifications that he had to make on one of his Montgomery pocket cruisers. He worked with the designer, Lyle Hess, to correct the problem, but the gist was that very small amounts of ballast can make a big difference in trim and righting moment.

The advice above about loading the boat first, with heavier gear further aft, is good. If you decide to add ballast, add it gradually. Another variable is tankage -- maybe you could use-up your forward water tank first, or if you only have one consider adding a second water tank somewhere aft so that you get something useful for the extra weight being hauled around?


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The boat was factory finished, with the exception of the mast & rigging. I'll try to track down that good old boat article, thanks for the suggestion.

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post #8 of 8 Old 04-10-2008
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It may be the case that modificiations/substitutions have been made over the last 30 years that affected the trim. Is the engine original ? Shaft ? Bearing ? Rudder ? Keel Ballast ? Tankage ? Batteries/location ?

I'm echoing others here - no need to try to make anything permanent. If you do decide to add more lead, build some type of framing that can hold the stuff in place securely, but don't glass it in. Hard to ensure that you're getting adequate load transfer. You don't want to end up with soft spots on the hull.

Good Luck !
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