Bert Vogelvang

Hi,
My name is Bert Vogelvang I am 60 years old and I live in Almere near Amsterdam. 5 years ago I bought my first boat in my live. I think it has sailnumber 173 but I'm not sure. It is stripped of everything but it has a set of new, not-original sailes. I sailed it now and than, just near Almere.
Now I have the following problem. There was allways some water in the boat but is became more and more. In the keel there was a screw to drain. This year I tried to repair some old cracks in the keel and the draininghole. A day after launching the boat this turned out to have been not succesfull. I bought some resin and glassfibre but the man in the shop told me to use it on dry surface only. So I widened the litttle holes and removed lots of mud, rust, sand en concrete. Inside the keel I can feel rotten pieces of lose wood. I am now waiting a few days. I think I can repair the outside but I don't know what to do with the ballast. Must the keel be filled again ? Can anyone advise me ?
Kind regards,

Bert Vogelvang
Hans Andreusstraat 16
1321 SL  Almere