[Public-List] Adding weight to the keel and other things

[Gordon Laco]

Good morning Len - 

Well some of you friends may recall me venturing into this field a few years
ago when I first bought SURPRISE.  Before I go into it - what do you mean by
'underweight'?   I assume the iron ballast keel standard to the A30?

 Here's what I think.

Since the A30 was intended by it's designer to have a lighter engine, and
lead ballast, and ended up somewhat overpowered with the relatively heavy
Atomic IV; and iron ballast (but for one exception I know about) the result
is that most of our boats squat a little.... And all are more tender than
intended.   This doesn't matter in one-design racing because we all suffer
equally, but in broad terms the squat and the ballast issues aren't good for
performance.

What you describe, Len, would result in a stiffer boat that would probably
be a better sail carrier.  That's to pro.

The con would be that it would no longer really be an Alberg 30 any more.
Maybe this isn't important to you.

One more comment... I would not worry about cutting away the fibreglass
where you are thinking of bonding your extra ballast.   I'd drill and tap
through the glass into the iron then bolt and glass your lead on that way.
If you avoided cutting away a section of glass you'd minimize the chances of
some compromise of the integrity of the encapsulation of the keel ballast.
Imagine a hard grounding making a crack...

Anyway - I too thought about all that.  I even thought about cutting off the
iron ballast and replacing it with an assembly of a new lead ballast keel
with deadwood to make up the diff in volume that I'd bolt on again using
traditional keel bolt/floor timber structures.   Of course that would be
horribly expensive but I thought about it.

While I was thinking about it I bought SURPRISE a new main and genoa; and
what ho? Suddenly the boat was dramatically stiffer.  I am embarrassed to
admit how surprised I was....

Gord #426 SURPRISE


On 02/05/11 9:50 AM, "Len Payne" <lenpayne at bresnan.net> wrote:

> Good Morning, All,
> I have been considering how to add weight to an under-weight keel.
> One of the things I have been thinking about is stripping the glass from the
> keel in an area just above (3 or 4 inches) the bottom of the keel and nearly
> the full length of the keel in that area. Then, by drilling and tapping 2 1/2"
> holes into the keel, through lead plates, to hold the plates to the keel on
> both sides. The plates would be 24" x 6" x 1", three on each side - laid
> lengthwise - end to end, would total about 1/2 cuft of lead (about 350#, 1
> cuft = 708#). Each plate would weigh just under 60#, so would be a manageable
> weight. The plates would be faired according to it's position on the keel and
> would be bolted to the side of the keel, epoxied in place, and glassed in to
> become an integral part of the keel. This would add nothing to the draft and
> would only a 2" to the width of the keel. The additional 300-350# would be no
> more than that of a large passenger, or a big skipper and beer, so it should
> not affect the way the boat rides in relation to the waterline. Furt
>  her, being 3-1/2' below the waterline, spread out along the keel length,
> fairly 'centered' relative to the center of gravity, the trim should not be
> significantly affected - certainly no more than a 40gal water tank under the
> V-berth (330# plus, above the waterline, very far forward). The additional
> "Righting Moment" of 300-350#, 3-1/2 feet below the waterline would,
> certainly, not be negligible.
> If one were about to strip the hull because of the need for a barrier-coat,
> how much additional work would it be to remove the glass down to bare iron (if
> the keel is cast) or attaching the plates to the outer skin of the keel and
> through-bolting to the opposite plate, then glassing the whole thing in place.
> Yes, I really want you comments, else I would not be soliciting same. Are
> there things that I have not considered? Other possible effects from doing
> this? Does anyone know "exactly" how the keels are constructed? Are they junk
> iron cast in epoxy, are they glassed, cast iron? Has anyone seen a keel that
> has come apart?
> Yes, I welcome any and all comments and/or suggestions.
> Thanks to all in advance.
> Len
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