water entry @ hull deck union

Well I replace the rubrail about 5 years ago by the time i redid the upholstery of the boat. I used those that are made from black pvc and then a stainless steel ribbon over it. ain´t other boat friendly as screws can rub other boats hull when too close...
after that i always saw the rear floor with some water eventhoug i haven´t skied. the thing is that after some inpection i determined that water is coming at the union of the deck and the hull... more in the back as its were the spray hit more when cruising.
I noted it as the hull walls in that area and around the motor bow sometimes have some water dripping....
To solve this I went with the 5200 and sealed all around the rub rail from below. But water still coming in.... In that case should I try sealing every screw?
Anyone with a similar problem?