Barn ....Again you are demonstrating a half baked incomplete understanding of quite basic physics, but never mind hey, because despite not understanding much you are never wrong.
Good night, I would ask you to turn the light of when you leave but clearly you like to leave it on even when no one is home ! 
Ah, finally a windsurfing topic worth registering for
I'd say Barn is right - once the pump has reached its nominal vacuum, the liquid and vapor inside the board will also reach equilibrium fairly quickly and will stay this way until the cows come home. Static system. This is in a perfectly "air-tight" board though.
If the board has holes drilled, then the pump will likely not be able to develop much vacuum, so the water will not evaporate quite as easily at the same temperature. However, the movement of new and dry air through the holes will have the triple effect of displacing vapour (and thus encouraging more evaporation); pushing water out mechanically (this is not out of the question, given the Styro core); and importantly - the air/nitrogen molecules will be interacting kinetically on the Knudsen layer (the thin boundary between liquid and vapour) which results in much increased evaporation. The last one is just a fancy way of describing what happens to your swimming pool water level on a windy day.
So IMO, holes and vacuum will be more effective than just vacuum, however, I'm all for spinning, because evaporation will likely leave most of the salts behind. Oh, and if you want to do "just vacuum", i.e. without drilling holes, then a cyclical pumping might be the way to do it, as long as you allow DRY air to enter the board during periods of no vacuum.
And hello everyone!
Who cares if vacuum can remove the water in theory. We all know you can't get 100% of it out so passing dry air through the board will be SAFE and as effective as any other method, maybe faster maybe slower, but safe and effective.
If you want to know all about water there is a book called water by Dr Ball.
The surface of water is always in a constant state of reaction thats why it evporates
sorry to hear about board
First the board should be weighed and compared to the specified original weight. I'll bet not much water at all has been retained and it's only in the immediate area around the plug.
I am a bit skeptical about a board collapsing from too much vacuum, I think air will find a way to leak in before that happens.
Someone should do an experiment and see if that is even possible.
I have an A/C vacuum pump and an old slalom board I don't want that is in really good shape but it doesn't have a vent plug, any ideas how to connect it?
Wow - just caught up on the whole 'scientific' argument going on here (over my head).
As Beaglebuddy mentioned, if the vent plug was left off after the board was removed from the water, due to the construction of the board, the water shouldn't have travelled far (although I know from experience that the 'pumping' effect from riding a board with the plug out will suck water toward the cells that are compressing/expanding).
Dunko - weigh it, wick it, leave it in a dry place for a few weeks & re-weigh it. A little bit of water won't hurt over a few years, sounds like these guys are a bit precious about their gear. As they say "...they still make 'em".
As a practical way of drawing the water out of the board i would put some sort of wick down the vent hole and stick it into the middle of a roll of dunny paper, the paper itself not the roll, or use a chamois folded up with the wick in the middle of it and put heaps of rock salt on top of and around which ever one you use and let osmosis do it's thing. I recon that doing this would make sure that the salinity outside the board is higher than inside and combined with the absorbent medium would draw the water out. Of course you may have to do this a couple of times depending on how much water got in but i think it would work so long as you don't do it on a day with 98% humidity.
I could be totally off the mark here but once the salt crystals inside the board left behind from the water start to dry out aren't they going to try and draw moisture back into the board so that would be my reasoning for increasing salinity outside the board. I've got no evidence to back this up it's just my "dark ages" way of thinking
i will post a picture when i stop mourning and can cope with going back to the shed.
to beagle- it definately got a fair amount in. i know this because i already got a lot out and it felt heavier. i don't have any spesific weights as it was a custom.
i can assure you an a/c vac pump would crush the board. it pulls down to 500 microns. one atmosphere is 760000 micron and 0 microns is a vacume (a true vacume is not a phisical possibility, all time and matter would stop, Correct me if i am wrong). so 500 is pretty dam low. we are talking about 0.07 Kpa.this is assuming the board is tight. i think i have proved it was relatively air tight, unfotunately
what i still do not get is how i had three other holes around the board plus vent hole and the nitro inlet and the only thing sealing them was pieces of blue tack?!
that **** is amazing...the board blew up first??
I can't believe I missed the post where DunkO blew up his board...
(must've skipped to page 2)
Ah well, typical seabreeze member (me) browsing, making comments without reading the 'whole' thread.
Pics (post-explosion) would be good though.
..
Who cares who's right or wrong about pressure and stuff.
I just want to see Dunkos pics of the exploded boards.
C'mon DunkO show us the carnage!!!!!
best method is have a CHInook style two bolt deckplate. your bung when fully removed 'clips' into the plate and is just big enough not to fall out. Have used this method for years, along with other mates i have told. the good thing is you caN NOT connect your mast base/go sailing until the bung is removed from the plate!!simple
