Check the o ring. Clean the seat where the o ring sits. Clean the threads so the screw closes easily.

To dry the board out you might try leaving it in the car in the sun, with the vent undone of course, for as long as it takes to get to a stage where it feels dry (weeks). Its important to get it as dry as you can. If you leave it wet for some time the water finagles its way into the styrene beads and then its very difficult to dry.

If you suspect there may be any leaks, close the vent, put the board in the sun for a half hour and put your ear to it to see if you can hear any gurgly or hissy noises. Mix up some detergent in water and splash it over the fin box, the mast track, the foot strap screws and around the edges of the pads. Look for bubbles.

Caveat - don't let it get too hot with the valve closed because if it isn't leaking it may delaminate if its damp inside. Then you'd be spitting.

Sorry but just in case.. are you undoing the air bleeder screw after sailing to release pressure and then doing it up again and putting it on the roof racks?
I hope not....

Rabs that is true... but what is "hot" ???? Any car, even in the far south of Oz and even with the windows down, will get pretty hot in summer.
I always undo mine, the only time it is done up is when it is in the water.

Even if the board does not get hot, and you never use it and just leave it on the back patio, just the heat cycling from 10deg in winter to 40 in summer on your verandah will surely induce some stress in the laminates as there is a lot of air in that styro core..
Further, a tiny bit of water in it will bubble the paint and make it look bad and reduce resale.

I'd rather not take the chance.

As for forgetting to do it, leave a screwdriver stuck in your footstrap or taped to yoru mast base.. whatever. It becomes second nature anyway.. today I sailed 3 x and every time I walked to the water I looked at the vent screw even though I knew I did it up and hour ago :)

I always remove the fins from my boards, so when fitting the fin i tighten the vent screw at the same time.
I only undo the vent screw when i get home and have the board out of the bag,don't think it a good idea to have a wet board inside the board bag and the vent screw open..lot of moisture in there.

Okay... now I am a little worried. I just went out to the board. Nice and warm in the sun, more drips and audible hissing/gurgling from the screw hole....................

This cant be good.

I also take all fins out my board (that way easier to move around and not damage etc.) and when i do i take the vent plug completely out. Then i just keep my fin screws and vent plug together so when i got to get the fin screws i cant miss it... that way i dont sail off without it which would be no good at all. We park in the sun most of the time and keep boards in our garage and things like that so i think it's best to take all the vent plugs out for that reason.

As for tim, just be patient. Dad smashed the nose of his board and a whole heap of water got in once. So we just turned it upside down and left it there for a couple weeks to let all water out (vent plug also out). So yeah not much else you can do i don't think. Good luck anyway.

Cheers
Bubs

After being in the sun all day upside down the drips appear to have stopped. I put the screw in half way through the day left it for a bit and then did the listening test right round the board and looking for salt bubbles. Nothing (next door thought i was barking mad).
Thanks for the o ring/cotton bud advice. I noticed this avo that the wife's board actually has 2 o rings. I will head to the shop tomorrow and collect some more with grease.
Thanks heaps for the advice everyone, really appriciated. all parts crossed.