Date: Tue, 10 Feb 1998 16:18:44 -0500
From: "TomTotem..." 
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]

At 07:07 AM 2/10/98 -0800, Dave Kruger wrote:
snip---------->
>An inch can make a substantial difference -- remember, the paddler is by
>far the largest load increment in a yak.  To see the effect of moving a
>180 lb paddler's body an inch fore or aft, try a 10 lb weight 18 inches
>fore or aft of the CG of the system.  A bag of lead shot is a good way
>to find how much/which way to move the seat.  The CG is probably pretty
>much directly under the center of your butt, when you are in the yak.

        Sort of on topic-I weigh in at a socking wet 138 lbs.  I've heard that my
Pursuit would paddle measurably better with a heavier paddler.   [and no I
didn't offer to sell it to the 180 pounder that said it! <g>]

        My question: Would the addition of bags of lead shot in the fore and after
compartments be a viable alternative to loading it with "kind of junk
that's heavy and will fit in the hatch?" <G>  It sounds good-I'm guessing
that I'd then want to put air bags on top of them to keep them stable-or
would velcro suffice?  The idea of having say 10 or 20 lbs of the stuff
flopping around during a roll. or brace doesn't interest me at all...

        Lastly, where does one purchase bags of lead shot?  Is it ridiculously
expensive?  Guess I'd never given consideration to using lead before...

        Tom...


Three left turns often make a right...



Date: Tue, 10 Feb 1998 20:27:46 -0500
From: Gabriel Romeu 
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]

I am very new to this group- in fact, never paddled before- got to do my
research though.  I do work in metal however, and if this sort of
ballast is reccomended, you might try sheet lead which is very easy to
conform to any shape, including the inside of the hull.  Lead is a very
toxic substance to touch (builds over time), so handle with extreme
care.  also coat it with an epoxy paint to protect yourself and
eliminate galvanic reactions to any other metal it comes into contact
with(less of a problem with lead as in steel, copper, brass)- this
reaction is compounded with saltwater.
You might find the stuff at a salvage yard, it was used extensively as a
roof liner.

Gabriel.....................................
http://users.aol.com/romeug .....furniture
................................
http://users.aol.com/romeugp ....paintings, photographs, intaglios,
objects
(this page is always under construction and update...all frames)



Date: Tue, 10 Feb 1998 17:54:39 -0800
From: Dave Kruger 
Subject: Re: [Paddlewise] Custom Cockpit [lead sheet?]

TomTotem... wrote:

>  My question: Would the addition of bags of lead shot in the fore and after
> compartments be a viable alternative to loading it with "kind of junk
> that's heavy and will fit in the hatch?" <G>
[snip] 
>  Lastly, where does one purchase bags of lead shot?  Is it ridiculously
> expensive?  Guess I'd never given consideration to using lead before...

Another poster suggested something even better:  lead sheet.  You could
probably bond Velcro to a cover sewn to fit the sheet and then attach
that to velcro contact cemented to the hull.

However, you would not want to put ballast into fore and aft
compartments -- decreases yaks ability to respond quickly to pitch and
yaw forces.  You would not like its sluggish turning behavior.  It would
be best to put it as close to the CG as possible -- just fore and aft of
your butt (or, underneath), and as low as possible.

Another idea is to investigate a yak more fitted to your body style.  I
weigh 220 lbs, so I need a high volume yak.  That's what I own.

-- 
Dave Kruger
Astoria, OR



Date: Tue, 10 Feb 1998 18:12:35 -0500
From: "TomTotem..." 
Subject: Re: [Paddlewise] Custom Cockpit [lead sheet?]

>Another poster suggested something even better:  lead sheet.  You could
>probably bond Velcro to a cover sewn to fit the sheet and then attach
>that to velcro contact cemented to the hull.

        Hmmm-slick!   I'll put this on the to-do list...  thanks!

>However, you would not want to put ballast into fore and aft
>compartments -- decreases yaks ability to respond quickly to pitch and
>yaw forces.  You would not like its sluggish turning behavior.  It would
>be best to put it as close to the CG as possible -- just fore and aft of
>your butt (or, underneath), and as low as possible.

        Hmmmm!  I hadn't given that possibility a thought-my rationale was more to 
limit the amount of lead required.  Now that you mention it though it does
make sense...

>Another idea is to investigate a yak more fitted to your body style.  I
>weigh 220 lbs, so I need a high volume yak.  That's what I own.

        Ahhh.... but what of my "stranded investment"??? <G>  Dave, I still 
haven't gotten off my b_tt and looked for a job! <G>  At $2200 a pop, I can 
only afford to do a little more trial and error... ;-)  Heh-really, the day
with G. Gronseth helped me learn to handle the boat much better, still...
Nothing is so good it can't be improved!

        -Based upon your suggestion I am more seriously considering a "NWK
Sportee" this spring, however I'm 6'0" but find the cockpit of my boat is
more comfortable than those of lower volume boats I've sat in...  <shrug>
Meantime I'll see if I can find a place that sells sheet lead and give it a
try [hopefully] soon.  Almost got to the water Saturday, but the clouds
came in, and I realized that I'd misplaced some of my gear when I moved
last week...  Perhaps this weekend....

        Hey, thanks again Dave, always appreciate your help!

                Tom...

[Kirkland, Wa.]
Three left turns often make a right...



Date:   Tue, 10 Feb 1998 20:59:22 -0700
From: Philip Wylie
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]

If there is room, why not pvc tubing filled with lead shot
and positioned in line with the keel as someone once
mentioned a while back , thereby providing for adjustable
trim and ballast.

Cheers,

Philip



From: Mark Zen
Date: Wed, 11 Feb 1998 02:37:21 -0700 (MST)
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]

>>Three left turns often make a right...

and two wrights make an airplane ;-) ... 

and on a MUCH more serious note, lead poisoning is serious, it is
cumulative, and stays in your system all your life, difficult to remove
heavy metals from the human body..

with that said, check a gun shop?? though i don't know the laws about lead
shot, i think it's illegal for hunting, but many reloaders use it for
skeet shooting, as it is softer than the barrel of their expensive guns
;-) me, i'd use steel shot.

put the weight as close to the center of gravity [CG] as possible. the
swing weight at the ends of your boat would make any boat feel like a pig,
as far as handling goes. you seem to be on the right track.

mark

#------canoeist[at]netbox[dot]com--------------------------------------
mark zen                      o,    o__              o_/|   o_.
po box 474                   [/     [\/              [\_|   [\_\
ft. lupton, co 80621-0474 (`-/-------/----')      (`----|-------\-')
#~~~~~~~~~~~~~~~~~~~~~~~~~~~@~~~~~~~@~~~~~~~~~~~~~~~~~~~@~~~~~~~~@~~~~~



From: Hank Hays
Subject: Re: [Paddlewise] lead shot?
Date: Wed, 11 Feb 1998 07:38:54 -0800

Hey John and all you other boat builders,

>One possible solution to the ballast issue:
>The lead shot can be bought from any
>gun shop in bags of about 25 lbs.

What do you guys think about all your efforts to design and build light
boats and then paddlers do this sort of thing to them???????  Like maybe
they should have bought the heavier fiberglass model in the first place,
rather than a lighter kevlar job?  <grin>

Hank Hays



Date: Wed, 11 Feb 1998 09:51:49 -0500
From: Richard Fawcett 
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]

One possible solution to the ballast issue:
I bought some straps from REI and "epoxied" one in the bow compartment,
one just in front of the seat, one just behind the seat, and one in the
stern compartment. I used 2 wide ice cream sticks to form an H on each
one to insure they would not pull up on the sides. I also used some wood
dust to make the epoxy about the consistency of peanut butter for a
really strong bond. I am going to use soft weights (can be bought in
various weights from any scuba shop) and basically cinch them down into
the bottom of the boat with the straps. I would suggest using straps
that are long enough so that when one is not using the weights, but is
packing gear into the boat, that the straps can double to go around gear
and secure the gear if needed.  It would seem that the straps could also
be used to secure "lead sheet" also.  I am toying with the idea of using
pvc pipe filled with lead shot.  The lead shot can be bought from any
gun shop in bags of about 25 lbs.  They sell for $17.95 a bag here in
Mayberry.
Hope this helps.

Richard Fawcett
Mayberry, NC



Date: Wed, 11 Feb 1998 10:41:44 -0500 (EST)
From: Michael Edelman 
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]

On Wed, 11 Feb 1998, Richard Fawcett wrote:

> be used to secure "lead sheet" also.  I am toying with the idea of using
> pvc pipe filled with lead shot.  The lead shot can be bought from any
> gun shop in bags of about 25 lbs.  They sell for $17.95 a bag here in
> Mayberry.

If you do use lead shot, make sure it's well sealed in the tube, and
consider adding something to seal the lead or keep it dry. Lead will
oxidize, and shot, having a large surface area, will oxidize fast in a
humid environment. For about 30-50% more than standard lead shot you can
get copper or iron plated shot that's more corrosion resistant. You can
also get steel shot, which is non-toxic if it does oxidize. 

Here's a thought: Take that bag of shot and drop it into an inexpensive
vinyl dry bag together with a few dessicant packs.

--mike

(anyone got any depeleted uranium lying around?) 

 -----------------------------------------------------------------------
 Michael Edelman                  

 http://www.mich.com/~mje/kayak.html



Date: Wed, 11 Feb 1998 10:49:52 -0500 (EST)
From: Kirk Olsen
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]

On Wed, 11 Feb 1998, Richard Fawcett wrote:

> One possible solution to the ballast issue:

I know two people who have ballast in their baidarkas.
One person uses 25 lbs of dive weights strapped to the floorboards
in the cockpit.  The second person uses lead shot in pvc tubing, he
also has 25 lbs worth (they paddle replicas of the same hull).
They use the ballast not to adjust trim but to help keep the boats
upright ;-)  

If you use pellets in pvc tubing be sure the end caps are secure and
won't accidently pull off if you catch the end cap on something.  Paul,
the person with the pvc/shot ballast, accidently pulled off one endcap
in his boat and another time lost an endcap in his truck.  He is still
finding pellets in his truck and boat.

kirk



Date: Wed, 11 Feb 1998 16:38:39 -0500
From: Kenneth Cooperstein
Subject: [Paddlewise] Custom Cockpit update [lead shot?]

I don't think adding dense ballast to a kayak -- even removable ballast
-- is a good idea.  You never know when you will need all the floatation
you can get.  Before I would use lead, steel or rocks, I would first try
wood or water -- both of which will not affect buouyancy in a swamped
craft.  As for water, I would use pool cover tubes or a poly water
bottle in the compartment where it is needed.

Ken Cooperstein



From: Craig Olson
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]
Date: Wed, 11 Feb 1998 16:47:07 -0800

Kenneth Cooperstein wrote:
> I don't think adding dense ballast to a kayak -- even removable ballast
> -- is a good idea.  You never know when you will need all the floatation
> you can get.  Before I would use lead, steel or rocks, I would first try
> wood or water -- both of which will not affect buouyancy in a swamped
> craft.  As for water, I would use pool cover tubes or a poly water
> bottle in the compartment where it is needed.

This isn't quite true.  While wood will generally float, it is still much heavier 
than air and will decrease the buoyancy of the boat.  Water weighs 62.4 lbs. per
cubic foot (8.34 lbs. per gallon) and will definitely decrease the buoyancy - a
swamped kayak doesn't float well because it's full of water!  As far as adding 2 5 or
50 lbs. of ballast, a typical yak has about 100 gallons of volume, or about 834 lbs.
of buoyancy.  Assuming a 200 LB paddler and 150 lbs. of hear, you still have over
480 lbs. of net buoyancy in the craft and 25 or 50 lbs. won't really make that much
difference.  My 2 cents.

Craig Olson
Bellingham, Washington



From: John Winters
Subject: Re: [Paddlewise] lead shot?
Date: Fri, 13 Feb 1998 09:41:06 -0500

Richard wrote;

> Canadian Ballast Rocks Caution
> 
> In the mid-1970s, Blair Chasty and I picked up some Canadian Ballast
> Rocks from Killarney (near Sudbury, Ontario), for decorative use in his
> exotic fish shop.  His store-front window was a massive aquarium.  After
> placing the rocks in the tank, he went home for the evening.  The next
> day his display consisted of a large number of dead fish.  Were it not
> for the statute of limitations, he would be holding you liable, John
> Winters.  Please stop peddling your environmentally toxic products over
> the net.  Your certificates of authenticity are fraudulent, for instead
> of selling Canadian Ballast Rocks, your are foisting Canadian Blast
> Rocks from the slag heaps of Sudbury.  Shame on you.
> 


It is precisely this kind of thing that we at Canadian Ballast Rock Ltd.
have been trying to prevent. 
Not all rocks (as Richard and his friend discovered) are equal. Indeed,
geological diversity is the rule even though one rock may look very much
like another to the untrained eye. To prevent such accidents, the Canadian
Government has established a licensing process that assures that all rocks
will be gathered by trained professionals and in an environmentally sound
manner. 

One does not simply pick up a few rocks willy-nilly, skip a few gracefully
across the water,  and then put the rounder rocks in your pocket for future
use. Not, at least, if you want to have children. 

Have you ever wondered why, here in this land of plenty with a McDonald's
at every intersection,  there were so few natives when the Europeans
arrived? Studies of early photographs clearly show that native people
carried rocks in small leathern bags close to their genitals. No doubt most
of these rocks were radioactive and resulted in sterility. This also
explains why candles were not discovered by Indians. Glowing body parts
sufficed.

Immigrant Europeans used the safer rock handling methods (bulldozers etc.)
and, instead of rocks, carried small bottles of rot gut around their
waists. In this way they avoided the perils of stone balls while the rot
gut stimulated them to greater reproduction levels. The rest is history. 

Why the normally observant Indians did not recognize the dangers of some
rocks is unclear. It has been suggested by the normally rational Professor
Inverbon that it was another women's plot to reduce the attentions of
native males who did not have cable and could not get Dr. Ruth on the local
station. I reject this out of hand. When touring a native burial site I
discovered a copy of Cosmopolitan secreted behind some tag alders. Is this
the
behavior of women who don't want sex?" 

Kayakers have been safely using ballast rocks for centuries and the old
skills of picking safe rocks from among millions of unsafe rocks would have
faded away had it not been for Canadian Ballast Rock Ltd. Modesty forbids
us from taking all the credit. Were it not for a 6.5 million dollar
government grant our ground breaking research at Club Meds around the world
would not have been possible and paddlers would be capsizing all over the
place, clogging up the oceans with overturned boats and making whaling
impossible for the Japanese and Makah natives.
... 
While we might weep for Mr. Chasty's fish Canadian Ballast Rock Ltd. can't
be held responsible for what amounts to nothing more the a petty theft gone
bad. 

Robert wrote;

>Furthermore the exporting of the product
>without permits and the approval of all governmental agencies shall
>require a complete review where all evidence shall be presented and
weighed
>before a tribunal.  Penalties shall be extracted by Mr. Winters at his
>leisure once the tribunal (Olympic in nature) has judged you guilty.

Uh, well, like you know, just as soon as I recover from my second hand drug
induced state. I mean like I don't use the stuff myself but I do inhale. 

I am confident that an Olympic style tribunal will enforce some one else's
rules when it seems convenienient to do so and impose unrealistic
penallties for something that was none of their business in the first
place. 

Next time downhill sea kayaking will be a demonstration sport at the
Olympics. No one will be allowed to participate unless drunk or drugged.
"No sir, that urine sample hasn't been tampered with. I really was blown
out of my mind. No, those aren't leaves of marijuana floating around in my
urine sample, those are little organic kidney stones."

Cheers
John Winters
Redwing Designs
Specialists in Human Powered Watercraft
http://home.ican.net/~735769/



From: Jim Champoux
Subject: Re:[Paddlewise] water or lead?
Date: Fri, 13 Feb 1998 13:17:36 +0300

I guess one big advantage of water would be that you dont have to carry it
when carrying or portaging your kayak, just empty and refill.

Jim Champoux
& Son
--------------



From: Michael J Edelman
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]
Date: Fri, 13 Feb 1998 13:24:22 -0600

Kenneth Cooperstein wrote:

> As to Craig Olsen's assertion that wood and water ballast *will* affect
> boat buoyancy, we are talking about different things.  I am concerned
> about buoyancy when swamped.  If you add lead ballast to your kayak and
> it fills with water, it could sink, whereas before the lead was added it
> might float -- unless you provided additional floatation.  If you add
> water or wood ballast, then you don't have to increase floatation
> because both are neutral or buoyant in a swamped boat.

But they're less dense, and so you need *more* to get equivalent stability, as
lead will be carried much lower in the boat, being 11.34x as dense. Water
ballast has a problem in that being neutrally bouyant it doesn't add any
resistence to heeling until it's actually out of the water. Sailboats that use
water ballast have to carry a *lot* of it, usually either side of the keel.
Water ballast is handy for trailerable boats, or if you're backpacking your
kayak as well, I suppose.

> For example, if you added 64 lbs of lead to a boat, you would need to

> add a 1 cu. ft. air bag to float that lead it if you swamped.  It is
> just simpler to forget the lead and instead add a 1 cu. ft. water bag to
> get the same 64 lbs. of ballast.

That's assuming you're totally swamped, of course; but if your boat is packed
well with air bags taking up most of the spare space that won't happen. More
likely is that you're talking about a situation where you have water and air
(in the form of a partially inflated bag) or water and lead filling an area.
Given a hypothetical kayak of 10 ft^3 volume, we could get 64 lbs of ballast
from 0.133 ft^3 of water or .012 ft^3 of lead. Assuming the rest of the space
is air filled, the boat has the same displacement in either case, but a greater
resistance to heeling with the lead.
--
Michael Edelman     http://www.mich.com/~mje
Telescope guide:    http://www.mich.com/~mje/scope.html
Folding Kayaks:     http://www.mich.com/~mje/kayak.html
Airguns:            http://www.mich.com/~mje/airguns.html



From: Kirk Olsen
Subject: Re:[Paddlewise] water or lead?
Date: Fri, 13 Feb 1998 14:06:34 -0500 (EST)

On Fri, 13 Feb 1998, Jim Champoux wrote:

> I guess one big advantage of water would be that you dont have to carry it
> when carrying or portaging your kayak, just empty and refill.

Have you got a good suggestion for keeping the water in one place?
I know I wouldn't want any ballast shifting around.  

I've rolled a couple of baidarkas which have removable lead/steel Bballast.
They definitely were easier to roll with the ballast in place, as 
the boats with ballast in place "wanted" to be upright.  These boats have 
about a 17" beam and use the ballast to lower the center of gravity, not 
adjust trim.  

kirk



From: Jim Champoux
Subject: [Paddlewise] water or lead?
Date: Fri, 13 Feb 1998 14:54:24 +0300

Kirk Olsen wrote
>Have you got a good suggestion for keeping the water in one place?

I dont have any experience at all on this.... I am just guessing... maybe a
length of PVC pipe (2' of 2"= approx 150 Cu in of water) with a male screw
plug at one end and a glued on cap at the other might work, strapped in
with nylon webbing? ,alhough it all sounds pretty big, size wise. or
maybe... how much water does a 60' coil of 1/2 " Tygon tubing hold.,150 cu
in?...Zip lock bags?..Evian bottles..?. Maybe lead is a better idea..on
second thought.

Jim Champoux



From: Craig Olson
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]
Date: Fri, 13 Feb 1998 14:14:04 -0800

Kenneth Cooperstein wrote:
> As to Craig Olson's assertion that wood and water ballast *will* affect
> boat buoyancy, we are talking about different things.  I am concerned
> about buoyancy when swamped.  If you add lead ballast to your kayak and
> it fills with water, it could sink, whereas before the lead was added it
> might float -- unless you provided additional floatation.  If you add
> water or wood ballast, then you don't have to increase floatation
> because both are neutral or buoyant in a swamped boat.

Hmmmm.  Are you really saying that you do not have 50 lbs. or so of extra buoyancy 
on board at all times, even when swamped?  If so, it would seem clear that your boat
is not equipped with secure flotation at both ends.  Having water-tight bulkheads &
hatches is not enough to qualify as "secure" flotation, as hatches & bulkheads can 
leak and hulls can be broken.  

When fully loaded, the dry bags within the front & rear cargo areas provide ample
flotation for you & your gear.  When empty, use inflated drybags in the cargo areas
to achieve the same purpose.  For boats without bulkheads, the dry bags must be tied
into the boat to prevent them from coming out in a capsize or swamped situation.  

> For example, if you added 64 lbs of lead to a boat, you would need to
> add a 1 cu. ft. air bag to float that lead it if you swamped.  

See above.  If you don't have an extra 64 lbs. of secured buoyancy, then your boat 
is not properly outfitted and could be in trouble if you get swamped.  You might
want to consider using sponsons - since we all know they're not affected by gravity.
 :-)

Craig Olson
Bellingham, Washington



From: "Craig Olson
Subject: [Paddlewise] Ballast Schmallast
Date: Fri, 13 Feb 1998 14:40:21 -0800

Michael J Edelman wrote:

SNIP
> Given a hypothetical kayak of 10 ft^3 volume, we could get 64 lbs of ballast
> from 0.133 ft^3 of water or .012 ft^3 of lead. Assuming the rest of the space
> is air filled, the boat has the same displacement in either case, but a greater
> resistance to heeling with the lead.

Your points are well taken.  One little thing, though.  You'd need 1.0 ft^3 of water
to get 62.4 lbs. of ballast.  (0.133 is one divided by 7.48, the number of gallons
per cubic foot)  The same ballast using lead would require about 0.13 ft^3. - i.e.
One ft^3 of water weighs 62.4 lbs. and 1 ft^3 of lead weighs about 490 lbs.  Lead
probably weighs a good bit more than this, since the 490 figure is for steel.  (My
book didn't list the weight of lead.)

Let's say we wanted 62.4 lbs. of ballast.  Then we'd need 0.13 ft^3 of lead, which
could fit in a 6" diameter by 7.8" long tube strapped to the inside centerline of
the hull.  Or - we'd need 7.5 gallons of water strapped down somewhere.  A cubic
foot of water (or anything for that matter) takes up a lot of space!

Having said all that, I agree that for most applications, the time needed to
assemble and install the ballast system might be better spent working on paddling
skills - braces & rolls - although that extra 50 FT-LBS. or so of righting-heel
torque could be very helpful to a roll in rough water.

Craig Olson
Bellingham, Washington



From: Michael Edelman
Subject: Re: [Paddlewise] Ballast Schmallast
Date: Fri, 13 Feb 1998 18:29:41 -0500

Craig Olson wrote:

> Your points are well taken.  One little thing, though.  You'd need 1.0 ft^3 of water
> to get 62.4 lbs. of ballast.  (0.133 is one divided by 7.48, the number of gallons
> per cubic foot)  The same ballast using lead would require about 0.13 ft^3. - i.e.
> One ft^3 of water weighs 62.4 lbs. and 1 ft^3 of lead weighs about 490 lbs.  Lead
> probably weighs a good bit more than this, since the 490 figure is for steel.  (My
> book didn't list the weight of lead.)

Whoops. Right. I had a beer with lunch. But the relationships hold. The specific gravity
of lead is 11.43, I think.

> Having said all that, I agree that for most applications, the time needed to
> assemble and install the ballast system might be better spent working on paddling
> skills - braces & rolls - although that extra 50 FT-LBS. or so of righting-heel
> torque could be very helpful to a roll in rough water.

Of course, those of us who use folding kayaks don't really know how to roll- since we
never have to. ;-) But I do recall Derek Hutchinson writing how he used a lead filled
tube to add ballast for photography from the boat. Even the experts use it!
--
----------------------------------------
Michael J Edelman      mje@mich.com
http://www.mich.com/~mje
http://www.mich.com/~mje/kayak.html
http://www.mich.com/~mje/scope.html



From: John Winters
Subject: Re: [Paddlewise] Custom Cockpit update [lead shot?]
Date: Sat, 14 Feb 1998 08:50:47 -0500

Kenneth wrote;

(SNIP)
> 
> For example, if you added 64 lbs of lead to a boat, you would need to
> add a 1 cu. ft. air bag to float that lead it if you swamped.  It is
> just simpler to forget the lead and instead add a 1 cu. ft. water bag to
> get the same 64 lbs. of ballast.

Lead weighs aprox. 700 lbs. per cubic foot. Thus 64 pounds of lead will
only take up 157 cu. inches of space. Since this can be mounted much lower
in the boat and centralized fore and aft much less of it can be used to
achieve the desired increase in stability or change in trim.  A simple
calculation of the moments involved will show that 50 pounds of lead
mounted on the bottom of a kayak will almost make it self righting. If
faired into the hull it will have no noticeable effect on hull resistance. 

Kevin wrote;

>If this is for improving stability, then I consider adding ballast an
>inferior approach. The best possible way to improve stability in your boat
>is to improve your technique and your fit in the boat. For the latter,
>there is a great article in the recent Feb issue of Sea Kayaker, for the
>former, I can recommend several ways to improve your balance and edging
>skills, from simple exercises to do while paddling, to a full-blown river
>kayaking course.

This is true for those activities where one is always alert. However, if
one is sleeping in the boat or there is a prospect of being at sea for
extended periods of time in which one must rest, ballast can provide the
required stability and it is safer than increasing the form stability.
Also, we have heard from handicapped paddlers who might not have the
ability to roll. In this case added stability that actually prevents
capsize may be a requirement. 

For most paddling stores and gear in a boat are a form of ballast that can
enhance stability. They can be stored in such a manner as to improve
handling and make paddling much less stressful when the weather gets
threatening. The obvious problem with stores is that they are consumable
and stability suffers with time (unless you have a holding tank aboard).
:-) 

If you are carrying water anyway then it is important to store it as low as
possible and outboard to reduce rolling. The containers should be
collapsible so the water will not slosh.  Of course, the containers should
be fastened tightly enough to prevent movement. We used the cheap folding 2
gal. jugs in Labrador. They worked but I never really trusted them and
covered mine with duct tape to prevent wearing holes in it. 

Returning to the origin of this thread, adding ballast specifically to
adjust the trim of a boat may not be the most efficient way to do the job
but it does work. A sliding seat is much more effective plus it provides
flexibility to adjust for less than perfect gear packing. I have used
ballast myself on sprint kayaks. We build the boats ten lb. under weight
and then shift the lead blocks around to get the best trim. We don't move
the paddler because the seats are rather tightly fitted into the best
paddling position for control and stroke efficiency. 

The important thing to recognize through any of these discussions is that
circumstances alter needs. One can alter stability in several ways and each
method has its virtues and vices. The wise paddler and boat designer will
recognize this and use each method in the appropriate manner. To
arbitrarily adopt one over the others is to invite problems. 


Cheers
John Winters
Redwing Designs
Specialists in Human Powered Watercraft
http://home.ican.net/~735769/