# Changing weight in keel



## lapworth

I could put more lead weights in my keel. I am assuming this would give me a longer water line. I also assume this would be illegal for racing?


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## Faster

It might give you a longer waterline.... it will also make the boat heavier, obviously, and created more wetted surface. If you're putting it high in the keel cavity it's debatable how much more righting moment you'd get, and whether that would be advantageous against the increased drag of surface and weight.

Illegal for racing? If PHRF there are mechanisms in place to adjust your rating with the ultimate effects of what you've done in mind. (of course, if you do something like this and don't tell them it would be considered cheating if in fact it helped you on the course) 

It's rarely effective to tinker with the original design unless it's a real bad one to start with....


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## tommays

Zzzooms PO had a keel done to change the draft from 5'3" to 7' BUT i sure would not have wanted to pay the bill 

We take a 13 second hit for the change


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## Ajax_MD

Lapworth-

There's a lot we can do to your boat to make it faster before going to such lengths as adding to your ballast.

Better sails, clean the hull, upgrade some hardware...


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## JohnRPollard

BubbleheadMd said:


> Lapworth-
> 
> There's a lot we can do to your boat to make it faster before going to such lengths as adding to your ballast.
> 
> Better sails, clean the hull, upgrade some hardware...


New skipper?

     

Just teasing, lap.


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## svHyLyte

When I was younger, it was not uncommon to see yacht designed for lighter air venues add a lead "shoe" to the bottoms of their keels for sailing in windier locales. An example of this is the Thunderbird 26 designed by Ben Seaborne in the early 1950's. T-Birds were designed under a commission from the WPWA (Western Plywood Association) as a means of promoting the use of plywood materials following the end of WWII. The boats were originally designed with sailing in the Seattle area but their ease of construction, speed and versitility made them popular in many areas with much more wind. My first "real" sailboat (ie keelboat) was a 1957 era T-Bird when we lived in San Francisco in the early 1960's. Because the wind was so great, however, the boat was fitted with a 500# lead "shoe" that allowed her to stand up to her canvas better and go like a scalded cat in comparison with her lighter weight sisterships.

Unless you have a very light yacht indeed, the addition of a few hundred pounds to your keel isn't going to have much influence on your waterline. It will however, make the yacht "stiffer" but will also make her motion in a seaway much faster--and in some cases uncomfortably so.

FWIW...


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## SlowButSteady

I used to have a Victory 21, a design that came in two versions; one with a bulb on the bottom of the keel, and one without. As I recall, the bulb added about 150 lbs., which was about 10% of the empty weight of the boat. The models with the bulb keel were actually preferred by most Victory owners, as they were considerable stiffer boats, but were a bit more sluggish in calmer conditions.


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## Gary M

I once owned a well known Canadian built 26 footer. It drew 4' and was rather tender in heavier air and therefore would not go to weather competively. 
I built a mold and added 5.5 inches which was 200 pounds of lead and attached it to the bottom of the keel. You could not tell that it had been modified. It made a huge diffrence, the C&C 27 MK1s that were easily beating us before were no longer a challenge and I did not detect any poorer performace down wind.

I raced in MORC at the time (still do actually) and took a modest hit for the modification but it was well worth it.


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## WDS123

This is similar to changing design of hull, since added keel weight would significantly change how hull sits in water.

Unlikely to be good idea.


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## sidney777

The San Juan 7.7 info I was just looking at shows a picture of a shoe .Quote,
"On the east coast in particular, light weight is essential for light air performance,however, the SJ 7.7 as initially design, was simply over powered. The fix was a keel'shoe' which was added to the bottom of the keel. The shoe added 4.5" of keel extension and 125 pounds to the weight. The 7.7's fixed keel drew four feet without theshoe, approx 4' 6" with it." http://sanjuan21.net/clark_boat_company_5.pdf
 They have a pic of shoe before installation.


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## svHyLyte

WDSchock said:


> This is similar to changing design of hull, since added keel weight would significantly change how hull sits in water.
> 
> Unlikely to be good idea.


Humm...

Let us assume a fairly commonplace weekend 28 foot racer/cruiser of mid 1970's vintage. For the sake of the exercise, she has fairly pinched ends (ala IOR) and fair overhangs. Accordingly, lets assume she has a LWL (substitute for Lpp) of say 23 feet and a Bw (waterline beam) of oh, say 7.5', and accordingly, a Block Coefficient of say 34%. Now our OP adds 500# of lead ballast to her keel, perhaps two half bulbs, bolted on either side right at the bottom of the 4' long tip of her keel. The result of the foregoing would add all of about 1-5/8" to the depth of immersion of the hull, if that, give hull flare. I'm not sure how the foregoing would have much effect on how the hull sits in the water, eh?

FWIW...


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## paulk

The original poster still hasn't told us what he's sailing. It could be a Hess cutter or a Rhodes 19. Adding weight to the keel could make lots of difference, or none. We need more information to provide better answers.


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## lapworth

I have a 1968 Trojan sloop. She's 24' racer not the cruiser Graham sailed. I can drop weights from in the hull.


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## Sailormon6

To sail well in light air, you must be able to induce the boat to heel. Adding a significant amount of weight to the keel would ruin the boat's light air performance. 

Also, one of the qualities of a racing boat that makes it fast is that it's very light, and can accelerate quickly and plane easily. Adding a significant amount of weight would make it much slower in both respects. 

I can think of a lot of ways it would hurt the boat's performance, and not many ways it would help.


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## Ajax_MD

Hm, Sailormon has a good point Lapworth.

Being as we're on the Chesapeake, so you don't want to give up your light air performance. You know how dead it gets around here. My boat only displaces a little more and I have a little trouble getting moving on light days.

I really gotta get me one of them 155%'s...


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## blt2ski

Bubble,

If you have really light winds like here in Puget Sound at times, make sure the 155 is really lightwt! I have a 3oc nylon drifter that works well in under 4-5 knot winds, and a string style 155 for the 5-15 knot days. 

Marty


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## paulk

The handicap people can adjust your rating if you subtract or add to your ballast. Why do you want to do this? It might be cheaper to reef when the wind picks up and sail fast when the wind is light than to add weight that you carry around when the breeze is heavy or light, and to sail slow in light air because of the added weight.


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## lapworth

paulk said:


> Why do you want to do this?


See how the boat handles. It's not very serious I could add weight in two seconds and take it off just as fast. I am still new to sailing so trying things is how I learn. I clean my bottom sometimes could use a new main sail, and I always try to make some else the captain ( John never offers ). I don't even know for sure if my ballast is correct, it is over 40 yrs. Old.


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## Ajax_MD

When you say you don't know if the ballast is correct, is that because the existing lead in the keel is easy to remove? For what it's worth, you could have the boat hauled and weighed if you suspect that you've been cheated of some of your ballast.

Obviously your ballast is encapsulated since you're talking about adding lead pigs from inside the boat. I guess if it's as easy as you say, then what the hell? Go for it and see what happens.


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## paulk

Without knowing more about the boat, it is hard to tell if adding weight would be a good idea or not. My web searches for a Trojan SAILboat have come up dry. This one's been sailed for 40 years without it -- why add weight now? A 24' wooden racer from 1968 (Is this a wood or fiberglass boat- that's how little we know about it?) is likely to be twice as heavy as a J/24, and it may take a lot of weight - several hundred pounds - to have any effect, especially if you're placing it in the bilge instead of down low on the keel itself. Too much weight in the bilge could strain the stringers and floors around the keel, and you'd suddenly find out how deep the water is where you are - and not with the depthsounder. While increasing the waterline theoretically increases your speed potential, the added weight slows you down. In the light air that the Chesapeake is known for, heavier boats will likely maintain their momentum better than lighter boats, but a 1968 boat is likely heavy enough already. Adding weight for "keeping going" in the light stuff is going to cost you in the time it takes to get going (with the additional weight) in the first place. If the boat isn't floating on her lines, they may have been painted incorrectly by the previous owner, or done when all his scuba gear, dinghy, outboard, fuel tank, chain and anchor were in the forepeak. Where things are stowed can make a big difference in how a boat performs. Concentrating weight amidships might be a better first move than adding more. Then, if you want to spend some money, get a carbon-fiber mast (15 pounds??) and new sails.


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## Ajax_MD

Paul,

The boat is a Lapworth 24. I believe it's actually a Gladiator or Spartan. Here's some info: Lapworth 24's


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## maru657

*Lead ballast*

I'm looking for lead ballast in the San Diego area.


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## Jeff_H

svHyLyte said:


> Unless you have a very light yacht indeed, the addition of a few hundred pounds to your keel isn't going to have much influence on your waterline. It will however, make the yacht "stiffer" but will also make her motion in a seaway much faster--and in some cases uncomfortably so.
> 
> FWIW...


At the risk of high-jacking this thread, and not wanting to nit-pick an otherwise useful post, I just wanted to comment on one aspect of this quote for a moment.

Assuming that the ballast is added low enough to do some good, it would add to the stability of the boat over all. It would not make the boat stiffer. 'Stiffer' as it is used in yacht design refers to initial stability (i.e. form stability). Adding additional ballast will generally increase the inertia of the boat and as such will actually slow the motion of the boat in a seaway, in other words, within reasonable limits make the boat's motion more comfortable.

Respectfully,
Jeff


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## Gary M

To explain a little further and build on what Jeff said, the boat that I extended the keel on was a 4000# 26 footer. It had 1700 pounds of lead fin keel and 4.0 feet of draft. We added 200 pounds of lead which was a 5.5 inch extension.

The weight added was not significant but the improvement to initial stability was quite noticeable. When we first stepped on the boat amidships, right after launching, we noticed it did not heel nearly as much. This improved initial stability meant that when sailing upwind a puff would tend to heel the boat less and drive forward more. 

When we did get heeled the additional 200 pounds down quite low helped us maintain a reasonable degree of heel and was noticeably faster.

It was very much worth the effort.


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## svHyLyte

Jeff_H said:


> At the risk of high-jacking this thread, and not wanting to nit-pick an otherwise useful post, I just wanted to comment on one aspect of this quote for a moment.
> 
> Assuming that the ballast is added low enough to do some good, it would add to the stability of the boat over all. It would not make the boat stiffer. 'Stiffer' as it is used in yacht design refers to initial stability (i.e. form stability). Adding additional ballast will generally increase the inertia of the boat and as such will actually slow the motion of the boat in a seaway, in other words, within reasonable limits make the boat's motion more comfortable.
> 
> Respectfully,
> Jeff


While Jeff is correct that increasing moment of inertia will certainly result in a decrease in angular velocity for a periodic rotation--just as a spinning skater extending his/her arms will slow the rate of his/her spin so that his/her angular momentum remains constant, our own experience with adding 500# of lead shoe to the keel of a 26' Thunderbird had the effect of making her motion rolling down wind under spinnaker feel "jerkier" in the sense that with a fairly constant wave period, more heavily ballasted she would build up a roll and then seem to "snap" back more so than she did before we added the extra ballast. Beforehand, she would lay down to leeward and oscillate over a more narrow range than afterward, rarely returning to vertical. This phenomena has been observed in other fairly narrow beam, heavily ballasted yachts in comparison with their lesser ballasted sister ships. For example, it was a particular complaint of Eric Hiscock of Wanderer III--a 30' yacht with a nearly 9 ton displacement on a 26.5' LWL x 8.5' Beam--during his trans-Atlantic and trans-Pacific passages with his wife. (Asked what improvement he would make to his yacht if any after the trip he responded "Greater Beam and a Sawn Off Counter"). (I suspect the foregoing arises due to the fact that it is the beam of the yacht that adds the "damping" to an otherwise undamped pendulum.)

On the other hand in the (better) daze of sail, San Francisco Timber Schooners were known to hoist bags of coal to their mastheads (thereby increasing their transverse moments of inertia) to slow their "snappy" roll in beam seas once their cargo's (and their cargos' addition to the ships' moments of inertia) had been discharged, making "deadhead" return voyages to "the City" (and, in fact, Mill Valley) more endurable for the crew.

As for the term "stiff", in the general "lay" vernacular, the term is used to describe a yacht's ability to stand up to her canvas but, just in case anyone misunderstood my meaning, that was the intention. A discourse in the technical vernacular might be more "accurate" but less well understood, no?

And here Homer Nods...


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