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Last update, December 12, 2009

Installing the Ballast


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Keel ballast



Dap, or some bath adhesive sealant or 3M Marine 5201


Note: If you are building the System Board, complete that step before installing the ballast.

The Ballast

You have received a single piece of lead ballast poured or molded for the EC12 hull. The hull is a one-design and all ballast by approved hull manufacturers will fit in this hull. The weight, shape and size of the ballast may vary but the keel fit will be the same. Should it not, the hull or the ballast did not come from molds produced since 2005.


This is a technicality that you should know. The further fact is that there are a lot of legal hulls out there and ballasts that will fit them. When in doubt...ask before you buy. The assumption on this site in building is that you have acquired a new hull from an approved manufacturer.


A ballast for the EC12 hull will have a fit in the hull like an old pair of Sperry Topsiders. There is a place where all the edges will seal fit and the unit is not comfortable in moving elsewhere. Play with it and you will see.


The pieces come in about the same weight, around 18.5 pounds. With the current processes of building this will give you a completed boat ready for the water will all things aboard at about 42.5" of waterline or less. It should not be less than 42" by rule and good sailing trim. The maximum is 43" by rule but you do not want to be there for competitive reasons.


If you find the sweet spot for this pig and follow the building practices on this site you will be into the balance of the boat.


What is Multiple Ballasting?

This is the part you hate, I know! But there is a long discussion on boat trim in the Dummy Reflection series that explains how multiple ballast is used and why. To simplify, there are two key issues regarding changes in ballasting; the trim of the boat in the water and the righting moment created by the ballast. Wind pressure forces the bow down while the boat needs to sail on its lines for best performance. Wind pressure causes the boat to heel. Too much heel, and to a lesser degree too little heel, reduces performance. If you are curious or as part of your decision process, this will be a worthwhile read. Also Chapter 2 in the EC12 manual Optimizing, has an excellent discussion of trim angle.


This is all that will be said about it. Very few are using it and if you do it is a decision you are locked into during an event. It is advanced study at some time and only should be considered if you are in the top of the fleet. It is recommended here not to go there till you know the path.



If you are using the checklist, do not glue the primary ballast in until it comes up on the list. It is easier to install the System Board mounts with it out of the boat.


In step 2 of the EC the ballast is prepped. Place the ballast on those marks and make sure it is comfortable there.


Reminder: incidents of ballast coming loose and ruining a boat are very rare. You don't have to get carried away with this. Drop testing an EC12 upside down is not recommended.


A small tube of bath sealant adhesive, like Dap, works fine. Take a moment to think. Is this the time to do this? What have I forgotten? Is the hull clean? Am I at the right place in the EC? Lay a large bead just short of where both ends will rest and wiggle in the primary ballast. Align it on the mark and snug it up. No pounding is necessary. You can tilt the cradle by lifting the aft end to level the ballast with the planet if you like. She is at rest.  That is all there is to it. Do not disturb till morning.


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