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Sizing Mars Stability Bulbs for E38 SD

Vaughan_M

New Member
Hello All,
I'm new to these forums, having recently purchased a 1982 shoal draft E38 from forum member John Butler. Among other modifications I'm considering is adding Mars Metals (MM) "stability bulbs" to the foot of the keel. I have contacted MM for their recommendations, as I'm sure they have manufactured bulbs for the same model boat in the past (see attached photos previously posted by rwthomas1)

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Alas, the company responded that they haven't kept the old designs and need specific design parameters from me before they can quote.

All that said, does anyone know how much weight would be appropriate to add to the bottom of the keel to improve the boat's stability? For some reason, I'm thinking 300 lbs per side (600 lbs total), and that's a guess with zero engineering to back it up.

Thanks so much,
Vaughan
 

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e38 owner

Member III
mars bulb

I do know of a e38 that added weight to the bottom of the keel. However, I am not sure he was pleased with the result. Although I have the racing keel there are many on this forum who have the shoal draft model. Both boats are a bit tender by nature compared to more cruisey boats. That said in most conditions we sail circle around those other boats. A friend of mine bought a 32 last year and was concerned that he rounded up and could not control the boat with a 150 in 25 knots of air. My suggestion fwiw is to sail the boat for a year. The boat does not need a lot of sail and with the right sails is quite balanced. I sail in place that has two wind strengths 0-5 or 25. We often race. The boat goes so well that except when racing I keep a number 2 on the furler about a 125 or 130. In light air if there is not enough wind for that who wants to sail anyway, When its blowing that alone with no main works great and is easy enough to handle. If your sails are blown out that will make a greater difference than the 600 pounds. (about 3 big guys on the rail)
 
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Randy Rutledge

Sustaining Member
Remember that the added weight will be dead weight until the boat heels over to quite and angle. One 200 lb man on the rail will do much more that the added weight.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
>>>A friend of mine bought a 32 last year and was concerned that he rounded up and could not control the boat with a 150 in 25 knots of air.

I run into this too. A surprising number of sailors today no longer have any sense of sail selection. They just let it all hang out and wonder why their boats are hard to steer, out of control and slow. Before roller furling it was a lot of work to change headsails down and up, and old mainsail reefing was a chore on many boats. Headsails were different weights of cloth, and if you left the big one up too long it was ruined. Before A-syms, some cruisng folk had three sizes of spinnaker, too, and carefully judged which was right for the day.

The irony is everything is easier now, the sails are indestructible, so nobody pays attention to reducing or adding sail area in response to conditions. Nobody even seems to know what "conditions" are.

For Vaughn:

My point is, the ERicson SD sails fine. It was designed that way. It may not point quite as high as the 6' version, but it will be a boon on Chesapeake Bay or the Inland Waterway--which is why it exists.

Allow me to suggest sailing the boat for a year or two before altering the keel. Personally, I hate major aftermarket mods unless they address some known design flaw--which an SD keel is not.

Oh, almost forgot--welcome to the forum!
 
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Cory B

Sustaining Member
New Main Instead?

Good points above, Ericsons do tend to heel more than other boats. And I believe the shoal draft already has extra lead in it to make up for the lack of draft.

On our first Ericson, it heeled excessively as well when I first got it. A little bit of experience with the boat, and replacing the old-but-serviceable mainsail with a brand new one, made a world of difference.

If your sails are on the older side, maybe consider investing in new ones first? Old blown out sails are harder to sail with and can push your boat sideways rather than pulling it forwards.
 

Vaughan_M

New Member
Good advice on stability bulbs

All,
I appreciate the sage advice, and will sail the boat for a year (at least) before doing anything. There are actually many items higher on the list.... I totally agree that paying close attention to sail flattening will help greatly with tenderness in heavier air.

One thing I love about the boat is that she sails beautifully on 140 genoa alone. We brought her down the Chesapeake Bay that way with 25-35 winds on our aft quarter, and it was comfortable. Besides, we were making 7.5 kts and surfing at up to 10.5. Really fun.

Btw, I'm still wondering about the weight & size of the stability bulbs in the pictures of Rob Thomas' boat.

Thanks again in for your responses,
Vaughan
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Another "Main" comment

When we bought our boat the PO had not kept up with any maintenance on the rig or sails.
One of my first upgrades was having the original main recut and changing the batten scheme to a more-modern two-plus-two (two full length up high and longer ones lower down) arrangement.
My local sailmaker called it a "tummy tuck" repair!

A few years later, the budget improved and we sourced a new dacron main, same batten system.

Getting excess bag out of the main really changes the angle of heel on reaches and when going to weather. The other thing to remember is that, historically, the reason for the existence of the large 150% genoa was the standardization of racing measurement of a sail inventory.
While at one time many boats had a 163% (and some even larger) there evolved an inventory of sails for racing in handicap classes (like PHRF) that could be better and easier understood by racing authorities, sail makers, and owners, and a "standard" "5555" inventory came into being.
Christian or Seth can explain this a lot better than I and likely correct me in many ways....
I was always racing one design in a smaller keelboat in my so-called salad days anyway! :)


The unintended outcome of this racing-oriented sail inventory was that new boats were often ordered with this Standard Sail Inventory, or sail makers would subtly guide owners into it when they purchased new sails... and for all the years (and subsequent) owners after that.... everyone believed that a large 150% genoa was just right (!) and only the timid would even order up a 135 compromise (dreaded word) and that only unmanly sorts of beings would sail with a 110 !!
:rolleyes:

OTOH, I raced our Ranger 20 mostly in the working sail class because it took only two of us to run it. When we raced with the 150 and the chute we had to find a third person.
When I did race our later Niagara 26 hard for a couple of seasons we did use the chute and larger genny -- with 4 or 5 guys on board, running the bigger inventory was not difficult. For I and the wife, we normally sailed with the lapper and main, only. The boat was wicked fast with any combination.

And that brings us back to your Ericson (and my Olson). These boats were designed from the git-go to be fast under sail. They were designed "from the outside in" as NA Ted Brewer once observed about what makes for a great sail boat. i.e. that nice cruising interior we enjoy was engineered AFTER the hull was created for speed under sail.
...... not like I have an opinion of course.... :egrin:

Cheers,
Loren
 

Neil Gallagher

1984 E381
Another E381 with a Mars Bulb

All the comments on this thread make perfect sense. New sails make a huge difference, sail trim is key. I purchased my E381 in FL and brought it back to TX. It had a Mars stability bulb on the SD keel, exactly like the pics in the thread. I can't comment on how they sail without it but I can tell you mine is not tender in my opinion. I sail primarily the Corpus Christi, TX area where our wind 15-20+ more days than not. I've also been successful club racing the boat. I think that sailing the boat for a year then looking at the modification makes sense. I did call Mars when I bought the boat and they had all the records, I believe they said the build added 660 lbs to the keel. Good luck!
 
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