Hi, Doug, and Group,

Addressing your last comment first, Mars, of course, as that's what they do,
is immediately ready to do it, even though the techie there isn't familiar
with the type. So, *I'm* not ready to do it without a great deal more
definitive information.

As to performance, since I'm not afraid of a deeper draft, shoal isn't the
issue. But if a Scheel gives the same performance as a deeper draft, having
a deeper draft to begin with would make the performance that of a
deeper-still draft. That's what I had in mind, and was excited about, but
found that it wasn't so (a designer does not a keel guarantee).

As to the caveats, I hear ya. Righting moment is interesting to me, just
because the ballast seems so small (and the more I research, the less
definitive the answers get, but it seems to be somewhere between 6 and 8.4k
out of 30 displaced, which I consider either minimal or criminal, depending
on the number), and with as big a boat as it is (244 D/L @ 30k), the
addition of a couple thousand pounds shouldn't notably affect performance,
but it might well make it stiffer. If I could add performance (the desired
side effect), that would be great.

However, as I do more research, I'm wary of the ability to add on, other
than FG fabrication (not weight) based on what I'm learning, and if it
doesn't improve the righting moment at the same time, I'm not interested.
Of course, I'm also learning that the information available on these boats
is both extremely sparse (well, call it hard to find, as I've not had much
success at it yet) and contradictory. Without better info, I'm not doing
anything - including buying one (regardless of the urgency impressed upon me
by others, the speculation about mental masturbation rather than boatbuying,
or the catcalls about yet more delay) - yet :{))

L8R

Skip (and Lydia, by proxy)

original left below for context
--
"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail away
from the safe harbor. Catch the trade winds in your sails. Explore. Dream.
Discover." - Mark Twain
"DSK" wrote in message
...
Skip Gundlach wrote:

So, we're looking at boats, and Henry Scheel comes to light. He's
patented
a keel that several manufacturers are paying royalties to use, and what
I
read suggest that rigorous tank testing holds out the superiority to
straight keels, so, presumably, it must be worth *something*...

The Scheel keel is "superior" in the sense that it allows less draft for
roughly
similar righting moment and windward performance. If draft is not an issue
then
there's no point.


...Now to the question. Have any of you done, or know someone who has,
an
addition of such a bulb/wing to an *existing* - not shortened - keel?

Yes, a few.


The
benefits I'd see are better holding, and more ballast, as low as
possible,
against a minimal overall increase in weight

"More ballast" isn't a benefit except with respect to greater righting
moment,
and there are issues there like the strength of the hull & rig, as Matt
has
said. The only vehicle that benefits from added weight is a steamroller.

"Better holding" I think you mean increased hydrodynamic efficiency ie
less
leeway. Adding a bulb isn't going to do anything for this. Adding a
home-brew
wing keel is not likely to help either, it takes very sophisticated design
to
produce a wing that doesn't add more drag than increased lift.



I'm more interested in experience stories, if there are any, or
engineering
reasons for or against, as opposed to 'I think it would...' information.

The boats Ive seen this done to were all relatively small, from 19 to 28
feet,
and none showed any improved performance IMHO and all suffered from
reduced
reserve bouyancy and were slower in light air.

I have seen a few boats have shoal keels with wings put on to reduce
draft, one
was a remarkable success in keeping the same sailing performance and
losing 2
feet off the bottom of a 7' keel. But it turned out a good bit more
expensive
than the owner thought it would be.

BTW I definitely second (or is it third) the suggestion to ask the people
at
Mars Metals.

Fresh Breezes- Doug King

Hi, Glenn, and thanks for your input (crossposted to RBB). I've left the
original thread attached to bring the RBBs up to speed.

Since you're building one, and have done extensive research on all aspects
of your boat, I'm interested to know what you'll do about a keel for RUTU
(apologies if it's been covered already some time in the past - I don't get
over to 'building' very often).

I'm also interested in your opinion, if you have one, of Mars Metals'
approaches to afterfits, and, if you've had any exposure to the
modifications I'm speaking of. Anecdotal experience suggests that it's a
neutral effect, or, worse, frequently, a negative effect. Of course,
perhaps the add-ons already identified were homegrown, and Mars Metals'
approach is engineered, which, of course, would make a tremendous
difference.

Thanks.

L8R

Skip

--
"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail away
from the safe harbor. Catch the trade winds in your sails. Explore. Dream.
Discover." - Mark Twain
"Glenn Ashmore" wrote in message
news:OAjEb.6979$JD6.5687@lakeread04...
The Scheel keel was developed back in the '60s but you don't see them as
often anymore. I know pacific Seacraft and a few other builders still
offer a Scheel option. The flaired camber at the botom adds weight down
low which imcreases righting moment for the same amount of draft.
Theoretically it also increases lift but increasing lift down low sounds
counter-productive to me. The outward flair and wide slow convex bottom
also disrupts the formation of the tip vortex to a limited degree.

The advent of bulbs and wings reduced the attractiveness of Scheel
keels. Besides adding more weight down low while maintaining the
thinner camber and shorter cord, bulbs also act as an end plate reducing
the tip vortex better than the Scheel and therefore total drag.

Skip Gundlach wrote:

So, we're looking at boats, and Henry Scheel comes to light. He's
patented
a keel that several manufacturers are paying royalties to use, and what
I
read suggest that rigorous tank testing holds out the superiority to
straight keels, so, presumably, it must be worth *something*...

However, just a Henry Scheel design does not a Scheel keel include. Too
bad...

For those not familiar, it's got some of the attributes of a wing and
some
of a bulb, but primarily greatly increases holding power and reduces
vortex
drag over that of a standard keel, particularly beneficial to a shoal
draft
need, without the anchor-digging-in attributes of a wing.

So, the boats I'm looking at don't have this keel. I've read of those
cutting off the bottom of a straight keel and adding a bulb, or
equivalent,
to achieve a shoal draft with the same equivalent weight. They've done
this
perhaps by somehow attaching at the bottom, or, as one site I
discovered,
bolting two lead halves to the remaining keel, forming sort of a bulb
wing.

Now to the question. Have any of you done, or know someone who has, an
addition of such a bulb/wing to an *existing* - not shortened - keel?
The
benefits I'd see are better holding, and more ballast, as low as
possible,
against a minimal overall increase in weight (projected is from 30000 to
maybe 32/33000 pounds displacement, with that increase also applying to
the
current 8400# ballast, light by my thought).

I'm more interested in experience stories, if there are any, or
engineering
reasons for or against, as opposed to 'I think it would...' information.

Thanks.

L8R

Skip (and Lydia)



--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Hi, Glenn, and thanks for your input (crossposted to RBB). I've left the
original thread attached to bring the RBBs up to speed.

Since you're building one, and have done extensive research on all aspects
of your boat, I'm interested to know what you'll do about a keel for RUTU
(apologies if it's been covered already some time in the past - I don't get
over to 'building' very often).

I'm also interested in your opinion, if you have one, of Mars Metals'
approaches to afterfits, and, if you've had any exposure to the
modifications I'm speaking of. Anecdotal experience suggests that it's a
neutral effect, or, worse, frequently, a negative effect. Of course,
perhaps the add-ons already identified were homegrown, and Mars Metals'
approach is engineered, which, of course, would make a tremendous
difference.

Thanks.

L8R

Skip

--
"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail away
from the safe harbor. Catch the trade winds in your sails. Explore. Dream.
Discover." - Mark Twain
"Glenn Ashmore" wrote in message
news:OAjEb.6979$JD6.5687@lakeread04...
The Scheel keel was developed back in the '60s but you don't see them as
often anymore. I know pacific Seacraft and a few other builders still
offer a Scheel option. The flaired camber at the botom adds weight down
low which imcreases righting moment for the same amount of draft.
Theoretically it also increases lift but increasing lift down low sounds
counter-productive to me. The outward flair and wide slow convex bottom
also disrupts the formation of the tip vortex to a limited degree.

The advent of bulbs and wings reduced the attractiveness of Scheel
keels. Besides adding more weight down low while maintaining the
thinner camber and shorter cord, bulbs also act as an end plate reducing
the tip vortex better than the Scheel and therefore total drag.

Skip Gundlach wrote:

So, we're looking at boats, and Henry Scheel comes to light. He's
patented
a keel that several manufacturers are paying royalties to use, and what
I
read suggest that rigorous tank testing holds out the superiority to
straight keels, so, presumably, it must be worth *something*...

However, just a Henry Scheel design does not a Scheel keel include. Too
bad...

For those not familiar, it's got some of the attributes of a wing and
some
of a bulb, but primarily greatly increases holding power and reduces
vortex
drag over that of a standard keel, particularly beneficial to a shoal
draft
need, without the anchor-digging-in attributes of a wing.

So, the boats I'm looking at don't have this keel. I've read of those
cutting off the bottom of a straight keel and adding a bulb, or
equivalent,
to achieve a shoal draft with the same equivalent weight. They've done
this
perhaps by somehow attaching at the bottom, or, as one site I
discovered,
bolting two lead halves to the remaining keel, forming sort of a bulb
wing.

Now to the question. Have any of you done, or know someone who has, an
addition of such a bulb/wing to an *existing* - not shortened - keel?
The
benefits I'd see are better holding, and more ballast, as low as
possible,
against a minimal overall increase in weight (projected is from 30000 to
maybe 32/33000 pounds displacement, with that increase also applying to
the
current 8400# ballast, light by my thought).

I'm more interested in experience stories, if there are any, or
engineering
reasons for or against, as opposed to 'I think it would...' information.

Thanks.

L8R

Skip (and Lydia)



--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

My keel is an 8,750 pound bulb/fin. It is sort of a compromise. One of
my criteria was good up wind and light air performance. When John Fox
started work on my design he had been building flat out racing boats so
the first proposal had a 9' draft wing. We compromised with a 7' draft
beavertail bulb. Beavertails count mightily against you in most
handicapping systems but that was not a concern for me.

As I said, the advantage of the bulb besides reducing draft for the same
RM is the end plate effect and the beavertail is supposed to split up
the remaining vortex.

I talked to Mars about casting it for me but their price was a little
over $1.40/pound plus some extra charges for waste disposal and
transportation if I provided the plugs and bolt frame. That was 5 years
ago. Being me, I set about collecting wheel weights and cast the bulb
myself a couple of years ago. I have finally built up the nerve again
and will be casting the fin just after Christmas. I figure to have
about 40 cents/pound in the finished keel. OTOH, the backyard may end
up with a Superfund designation some day. :-)

Mars does sell a bolt on winglet set for shortening keels but it takes
some design work to figure out the weight and location so that your RM
does not change much. There has to be a careful balance of added weight
and higher center of gravity. Also if the keel has a large dihedral
shortening the keel will shift the lateral center of force forward which
might make the boat a bit squirrley and hard to trim out. I would call
Mars and see what they say. They have already done the engineering and
have patterns for many different hulls. No matter what they say, ask
for references for boats similar to the one you are contemplating
modifying and check with the owner for actual results.

Keel design is a balancing act between stability, performance and
comfort. Production boat designers spend a lot of time and money trying
to arrive at a happy compromise that is best for the market the boat is
intended to compete in. Ssmall changes below the waterline can make big
changes in the way the boat sails. Some can be good but more can be bad.

Personally I would not consider a complete re-keeling of any boat. It
would be outrageously expensive and you run the risk of changing the
sailing characteristics of the boat in unpredictable ways.

Skip Gundlach wrote:

Hi, Glenn, and thanks for your input (crossposted to RBB). I've left the
original thread attached to bring the RBBs up to speed.

Since you're building one, and have done extensive research on all aspects
of your boat, I'm interested to know what you'll do about a keel for RUTU
(apologies if it's been covered already some time in the past - I don't get
over to 'building' very often).

I'm also interested in your opinion, if you have one, of Mars Metals'
approaches to afterfits, and, if you've had any exposure to the
modifications I'm speaking of. Anecdotal experience suggests that it's a
neutral effect, or, worse, frequently, a negative effect. Of course,
perhaps the add-ons already identified were homegrown, and Mars Metals'
approach is engineered, which, of course, would make a tremendous
difference.

Thanks.

L8R

Skip


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

My keel is an 8,750 pound bulb/fin. It is sort of a compromise. One of
my criteria was good up wind and light air performance. When John Fox
started work on my design he had been building flat out racing boats so
the first proposal had a 9' draft wing. We compromised with a 7' draft
beavertail bulb. Beavertails count mightily against you in most
handicapping systems but that was not a concern for me.

As I said, the advantage of the bulb besides reducing draft for the same
RM is the end plate effect and the beavertail is supposed to split up
the remaining vortex.

I talked to Mars about casting it for me but their price was a little
over $1.40/pound plus some extra charges for waste disposal and
transportation if I provided the plugs and bolt frame. That was 5 years
ago. Being me, I set about collecting wheel weights and cast the bulb
myself a couple of years ago. I have finally built up the nerve again
and will be casting the fin just after Christmas. I figure to have
about 40 cents/pound in the finished keel. OTOH, the backyard may end
up with a Superfund designation some day. :-)

Mars does sell a bolt on winglet set for shortening keels but it takes
some design work to figure out the weight and location so that your RM
does not change much. There has to be a careful balance of added weight
and higher center of gravity. Also if the keel has a large dihedral
shortening the keel will shift the lateral center of force forward which
might make the boat a bit squirrley and hard to trim out. I would call
Mars and see what they say. They have already done the engineering and
have patterns for many different hulls. No matter what they say, ask
for references for boats similar to the one you are contemplating
modifying and check with the owner for actual results.

Keel design is a balancing act between stability, performance and
comfort. Production boat designers spend a lot of time and money trying
to arrive at a happy compromise that is best for the market the boat is
intended to compete in. Ssmall changes below the waterline can make big
changes in the way the boat sails. Some can be good but more can be bad.

Personally I would not consider a complete re-keeling of any boat. It
would be outrageously expensive and you run the risk of changing the
sailing characteristics of the boat in unpredictable ways.

Skip Gundlach wrote:

Hi, Glenn, and thanks for your input (crossposted to RBB). I've left the
original thread attached to bring the RBBs up to speed.

Since you're building one, and have done extensive research on all aspects
of your boat, I'm interested to know what you'll do about a keel for RUTU
(apologies if it's been covered already some time in the past - I don't get
over to 'building' very often).

I'm also interested in your opinion, if you have one, of Mars Metals'
approaches to afterfits, and, if you've had any exposure to the
modifications I'm speaking of. Anecdotal experience suggests that it's a
neutral effect, or, worse, frequently, a negative effect. Of course,
perhaps the add-ons already identified were homegrown, and Mars Metals'
approach is engineered, which, of course, would make a tremendous
difference.

Thanks.

L8R

Skip


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Skip Gundlach wrote:

As to performance, since I'm not afraid of a deeper draft, shoal isn't the
issue.

Draft is always a key issue in cruising.


But if a Scheel gives the same performance as a deeper draft, having
a deeper draft to begin with would make the performance that of a
deeper-still draft.

Sorry, it doesn't work that way. Especially with a slow heavy boat. It's most
likely that there would be no measurable difference in this boat's sailing
performance between the Scheel and regular keels.


.... the ballast seems so small (and the more I research, the less
definitive the answers get, but it seems to be somewhere between 6 and 8.4k
out of 30 displaced, which I consider either minimal or criminal, depending
on the number), and with as big a boat as it is (244 D/L @ 30k), the
addition of a couple thousand pounds shouldn't notably affect performance,
but it might well make it stiffer. If I could add performance (the desired
side effect), that would be great.

If the ballast/disp ratio is only 28% then you'd have to add a lot to make any
difference, and this would make the boat heavier & slower yet. Although every
little bit helps when the boat is at 90 degrees

It sounds to me like you've found a boat that meets your needs room-wise and are
now beginning to wonder about it's sailing performance. There's no such thing as
a Perfect Boat... if you want it all, you have to take extreme measures like
Glenn A. who is building his own.

Fresh Breezes- Doug King

Skip Gundlach wrote:

As to performance, since I'm not afraid of a deeper draft, shoal isn't the
issue.

Draft is always a key issue in cruising.


But if a Scheel gives the same performance as a deeper draft, having
a deeper draft to begin with would make the performance that of a
deeper-still draft.

Sorry, it doesn't work that way. Especially with a slow heavy boat. It's most
likely that there would be no measurable difference in this boat's sailing
performance between the Scheel and regular keels.


.... the ballast seems so small (and the more I research, the less
definitive the answers get, but it seems to be somewhere between 6 and 8.4k
out of 30 displaced, which I consider either minimal or criminal, depending
on the number), and with as big a boat as it is (244 D/L @ 30k), the
addition of a couple thousand pounds shouldn't notably affect performance,
but it might well make it stiffer. If I could add performance (the desired
side effect), that would be great.

If the ballast/disp ratio is only 28% then you'd have to add a lot to make any
difference, and this would make the boat heavier & slower yet. Although every
little bit helps when the boat is at 90 degrees

It sounds to me like you've found a boat that meets your needs room-wise and are
now beginning to wonder about it's sailing performance. There's no such thing as
a Perfect Boat... if you want it all, you have to take extreme measures like
Glenn A. who is building his own.

Fresh Breezes- Doug King

Mars Metals makes decent keels, no doubt about it. But they are a casting
facility, not yacht designers.

Run any of your idea past a yacht designer / naval architect to see if:

- the internal structure can take it
- the modification will improve performance
etc.

I think it would be a very hard to make a better keel with add on bulbs and
*improve* performance. More likely to just make things a bit worse. On
some boats you may be hard pressed to tell the difference


--
Evan Gatehouse

you'll have to rewrite my email address to get to me
ceilydh AT 3web dot net
(fools the spammers)

Mars Metals makes decent keels, no doubt about it. But they are a casting
facility, not yacht designers.

Run any of your idea past a yacht designer / naval architect to see if:

- the internal structure can take it
- the modification will improve performance
etc.

I think it would be a very hard to make a better keel with add on bulbs and
*improve* performance. More likely to just make things a bit worse. On
some boats you may be hard pressed to tell the difference


--
Evan Gatehouse

you'll have to rewrite my email address to get to me
ceilydh AT 3web dot net
(fools the spammers)

"Evan Gatehouse" wrote

I think it would be a very hard to make a better keel with add on bulbs
and
*improve* performance.

Like any other mod to anything, that depends on what 'performance' you want
to improve. Shortening a deep fin keel, for example, then adding a 'torpedo'
at the bottom will decrease draft and may make the boat more stable - at the
expense of more water resistance and slower turns. So a brown water cruiser
would say the boat's performance was improved whilst a racer would say it
was ruined.