Air valve not watertight
After a few days in the hot sun, I think that the board is as dry as it can get. It weights 7.8kg with starboard's catalog weight at 7,6kg and for sure I am in the margin of +-6%.
Also, by "listening" to the board I don't hear anything anymore, and the kitchen paper in the vent comes out completely dry.
But I see that the valve itself is not watertight: Today I put a proper O ring to the valve and after putting soap bubbles above the closed air plug, I saw air coming out from the seam between the screw and the board . I tested it with the screw more tight and more loose, and I noticed that the tighter the screw, the leak is weaker. But the thing is, the vent is not watertight. I took the screw out and tested the "walls" of the vent to see if the leak is coming from there, but no.
Is it possible that the geometry of the vent changed due to pressure from the interior of the board?
Is there in your opinion anything else I can do before taking the board to a professional?