Ten rater

Hi everyone, im new here.

I have just recieved plans to build the stratus, its a 10 rater at 1.2 M. Anyway, I have built before, My first was the nimbus, it is a 1 metre. (sorry if these are all well known names, im not sure). Anyway, I only put about 1kg of lead on the keel and it sails badly, I have sorted it know with a 2.5KG weight. Anyway, what weight do I need to add for the 10 rater, I am not sailing it in any races or anything, Just mucking around at the weekend, so it doesn’t have to comply to any standards. With the plans that I buy it never seems to quote the weight that the keel should be.

Thanks
Joe

My Viper 10R from Sterne has 8# of ballast with a total weight of 11#. That is with the “A” Sting-rig of 1470 sq. in. Sterne’s boats are on the light side. All kevlar hull. Fabric deck.