I don't think you can be that specific, depends on board construction, I've got a mate with a NZ Styrotech that doesn't have a plug, it's been airfreighted and left in the back of hot vans, about 20 years old and still OK. (I guess there's a chance it's made from closed cell styro but I doubt it.

I've seen other boards blow their bottoms even though their owners say they always loosen the plug.

It's a statistical chance, the more you leave the plug done up the greater the chance of blowing the bottom.
It's up to you, how much of a chance you want to take.

There are strategies that people use to make sure the bung gets done up before hitting the water, there's been several discussed here, I can't remember them all. Hopefully others will give us a new list.

It's also possible to convert to a gortex vent, but as far as I'm concerned the jury is still out on that.
I've done 2 boards, so far so good, but I did have a test vent block up on me after it had water on both sides.

Any time the board is not in the water.

I loosen it after every sail before it goes in the board bag and retighten it before I put the board in the water.I've got into the habit of doing it after I put the fin in so I don't forget.
If I come in and the board is going to be left in the sun I loosen it and put the screwdriver somewhere on the board where it's a nuisance and I can't miss it!
I've got Tabous and you can do that.. I get the impression that other brands you have to take the plug right out to work..???

So here's how i think about it. You do the plug up on an average to warm temperature day and leave it done up. It goes in the car and expands a bit in the heat but enough to damage it "?". You put it in the water to sail and it contracts a little but enough to damage it, obviously not.
If you leave the plug out and it's a really hot day then you do it up then throw the board straight in the water to sail there is probably just as much contraction except at a much quicker rate due to the water being much colder as what you would get expansion if you left the plug in and put the board in the car. Which one is worse for the board i don't know but i do know that if i forgot to do up the plug then that would be worse than both and so would getting a little piece of sand under the o-ring that made it leak or if the o-ring split when you were doing it up because you used it one time too many. So mine stays done up permanently because in my opinion there is much less chance of the board getting damaged by temperature variation than what there is from a stuffed o-ring or being in a rush to hit the water one day and forgetting to tighten it.
That is unless you own a JP because you can't put the mast base in the slot if the vent plug is loose because it is behind the mast track. Good idea i think if it's not just a fluke but you can still wear your o-ring out.

Not sure it would be wise to put a wet board in a board bag with a open vent plug.

I leave mine tight unless I know it's going to be very hot and left in the van.

Agree with Shear Tip, Mike. I used to undo the screw after sailing but after reading about how this may result in water getting into the board if the board and straps are wet, I don't worry about undoing it.

After about 5 years of boards with plugs and not undoing them I'm yet to have one have an issue with the hull due to pressure differences that I know of. They have all been Tabou boards.

I've seen this debate on a number of occassions and at there isn't a definitive answer.

I've been sailing for 20 years and owned countless number of boards in different constructions. I leave the plug in and have never had a problem.

At one stage I did try taking the plug out and managed to forget to refit it, drenched the board.

I hear a lot more stories of people damaging boards by forgeting to refit the plug than having them blow out.

It would be interesting to hear what a manufacturer would say on this topic WRT warranty.

In the short time I did remove the plug I paid careful attention to to keeping the threads clean from sand and the condition of the O ring. I often found that sand particles (floating around inside the bag) would find their way to the threads. So you need to check thoroughly before re tightening. To me this is a pain in the A, when i get to the beach i want to get in the water ASAP.

I've always loosened the plug after every sail, after blowing the residual water out of the area.

I was interested to see JP Australia finally put something in print regarding this question:

JP Australia User Manual
"PRESSURE VALVE
The “valve” or "pressure release screw" (at the mast box) compensates the difference of air pressure inside and outside the board (mostly caused by extreme temperature / sun exposure).
• close the valve for sailing
• otherwise it should be open.
Very important: Make sure that the valve is open when traveling by plane !
Keep/store your board in a board bag to prevent unnecessary sun exposure, scratches, other wear and tear."

With regard to "forgetting", when I install the mast base I tighten the vent and check the fin bolt.

I also check all the foot strap screws occasionally. They loosen a little, mostly in the first season.

this is a good thread for who not to buy second hand boards from...

ka43 said...
Mike makes a good point. Ive always loosened he plugs in my boards after a sail but of late have stopped doing so straight after a sail. If its a very hot day or board has been sitting in the sun I will quickly loosen it to release any pressure build up then re-tighten (to stop moisture from wet straps etc getting into board) before I put in the bag and car for trip home.
Once home I put the board with vent plug undone on board rack.
Like a lot of things its a habit you get used to.
I guess if it made no difference then manufacturers wouldnt put that warning sticker on their boards.

Mm good idea I suppose.Another habit Ill have to get into..

I always remove the vent plugs. I don't see what the big problem is, takes about 5 seconds to screw it in right after screwing in the fin.

seanhogan said...
I have four boards packed in my van (all year round), never undo the plugs, never had a single issue. been doing that for years.

This is saying something. A couple days when I was in New Cal recently it felt so hot I was wishing I had a valve on my head, as it was about to go pop.

I guess, as I said earlier, this is one topic that the windsurfers will remain divided on (much like do i need to wash my sails after a sessison). There will be those that stay plugged and others don't...pick your club.

Enough talk, time for action, honking NE'er in Sydney atm.

I've had a JP in the back of my black van (along with 4 others) all summer long, actually for the last 4 summers including 3 stints in WA in the middle of those summer. My van has no ventilation and I've witnessed sunglasses melting on the dash board and guess what, all my boards are still ok. I've had one board replaced under warranty form JP and they never asked if I removed the vent plug after sailing, only after chopping this board in half with a saw did the vent plug get removed....I still have it as a keep sake. In the early years I removed the vent plug, after a post like this one actually. The very next sail I forgot to put the plug in, had I not stopped to talk to someone I would have hit the water and been in all sorts. Lucky the wind died off and I packed up before getting wet and then noticed the plug missing, lucky for me!

I only ever plan to remove them if flying.

good board bag provides great insulation, can be stinking hot in the shed pull out the board from the bag and they are alot cooler

d1 said...

CJW said...
It's honestly way more trouble that it's worth, for all the reasons listed above by anyone with half a clue

Yes, half a clue... Here is the viewpoint of someone with more than that - scroll down to "Q: my board has a vent plug. Should I open it when I'm not sailing?"): boardlady.com/faqs.htm

Board Lady doesn't know everything, especially when it comes to pressure. Because she thinks pulling a partial vacuum on a board will evaporate (boil) the water inside. That's less than half a clue.

Anyway, bungs are the worst thing ever. First, there's no washer, so the O-ring is twisted and distorted every time you tighten it. Then there's all the sand and salt that gets in there fudging up the seal.

More importantly, why the fark do companies put the bung at the mast track. Put it at the nose or the tail so you can actually get the water that bungs inevitably leak in, back out.

I've sent this info graphic to all the major brands, clearly pointing why the bung is always at the bottom.




We should see bungs correctly installed for the 2014 boards.