Hi all,

So the stupid thing has happened: I went out windsurfing for the first time in about a decade yesterday afternoon, with my brother who hasn't windsurfed in even longer. He was on my old RRD 155L board, and I hadn't noticed but the drain plug wasn't installed at all. Noticed about an hour later once we swapped boards so I could help him with the trim of his rig. We came back in and when I got the board home I've got it resting level face-down with some paper towel stuck into the drain hole like a wick, and a little bucket under the hole. Not a lot (if any) water seems to have come out overnight but it may have evaporated (though it doesn't help that it's cold and rainy here in Sydney).

Wanted to see if anyone had any advice. I've read a few of the threads on here and seen some recommendations about drilling holes in the nose/tail and using a vacuum pump - anyone have any suggestions for where to find such a pump? Does anyone know anywhere in Sydney that would be able to help? Or any other advice would be appreciated.

Cheers!

You may not have sucked in much water . Sometimes they do , sometimes they don't . The inner foam is not very porous and may not have got in too far. I wouldn't do any evasive surgery unless you know a lot of water got inside. Can you find out how much the board weighed new ? Weigh it without straps . If it's not a lot , or you don't know , I'd leave it in the sun behind a window with the wick hanging out the hole . If the wick ends up dry in a week , you should be ok. Vacuum surgery is dodgy at best and will cost you more than the board is worth. You would need a pump that can run 24 hours a day for a week.

Happened to me too.... Just leave the piece paper towell and in the sun monitoring. No worries though. It takes a while to add up.

Thanks Imax1 and Manuel7. I've reached out to RRD as the board is from 2008-2010 or something and I can't find the specs for it online. Hopefully they will be able to come back to me with the original weight. I suspected that might be the story with vaccum surgery but thanks for confirming.

All good advice above but i will add that i suggest ignore the factory weight as its +/- about 5% ..... so say 300g for that board and i doubt the little bit of rare water flow over deck managed to put more than that in it.

Ram the wick in so u know its contacting the core hard, it will draw it out
I bet its good in a few days

As above, but the way to tell, is take the wick out when it gets cold and see how wet it is. When it comes out dry, you're done

Bit of clear plastic, clingfilm or something similar over the hole put it in the sun for a few minutes and see if you get any condensation. Worry about how to get it out once you know if it's in there

A friend extracted 1kg from my RSone board with time and this pump he made.

I had damage under EVA foam I'd put on the nose for protection but yeah, was hiding damage all season.
Water would come bubbling up out of vent screw when left in sun.

?feature=share

Select to expand quote

dieseagull said..
He was on my old RRD 155L board

It's fortunate for you that he was on a big board, where the vent opening was above the water most of the time. So chances are it mostly sucked air rather than water when if contracted as the board cooled when put on the water.

Thanks all, The board has been outside with a wick in it all week and the wick isn't soaked, just slightly damp at the bottom where it's contacting the core. I'll keep it like this for a while. Also had our first sunshine for the week over the last 2 days (though I wouldn't describe it as warm) so that'll help.

Select to expand quote

boardsurfr said..

dieseagull said..
He was on my old RRD 155L board

It's fortunate for you that he was on a big board, where the vent opening was above the water most of the time. So chances are it mostly sucked air rather than water when if contracted as the board cooled when put on the water.

You haven't seen my brother windsurf not that I'm much better. There wasn't much wind so we were both slogging most of the session which didn't help. But yeah, at least it wasn't a sinker.

I remember back in the day, people setting up washing machine motors, drilling a hole in each end and running it for days. Probably polyester boards.

well, if starting into a project like this, i'd suggest weighing the board before starting and periodically while drying, taking notes to see when it stops losing weight. otherwise, besides the paper towel strip wedged into the foam, you can add an aquarium air line and air pump to provide good air circ. cut the end of the tube at a sharp angle to ensure good flow :)

Select to expand quote

LNC said..
well, if starting into a project like this, i'd suggest weighing the board before starting and periodically while drying, taking notes to see when it stops losing weight. otherwise, besides the paper towel strip wedged into the foam, you can add an aquarium air line and air pump to provide good air circ. cut the end of the tube at a sharp angle to ensure good flow :)

Aquarium pumps push air. It's not good practice to push air through a board. It's better to suck it through. Aquarium pumps suck through dispersed apertures so you can't use them for suction unless you put them in an air tight container and have them blow the air out of it. Then hook up the vacuum line to the container. That's what I've done in the past. It seems to work ok.

Oh heck no. Don't ever push air into a board. Risk of delaminating the skin. Always pull a vacuum.

Select to expand quote

Aquarium pumps push air.

They can easily be inverted... just a matter of valves.
Very practical for low and long pumping.

Select to expand quote

segler said..
Oh heck no. Don't ever push air into a board. Risk of delaminating the skin. Always pull a vacuum.

You need a regulation on the vacuum. You could crush the board if you go over 0.5 atm. Better stay above 0.3.

I believe we have a misconception here as what is being referred to as a drain plug is, in fact, a vent plug. It's primary purpose is to prevent pressure building up in the board causing delamination as a result of fumes being given off by the internal foam and adhesives when the board gets hot, or as a result of the reduced pressure of an aircraft cargo hold.

Having made boards myself back in the day, how much water would get in when a vent plug is left out depends on the core material and how well the skin remains laminated to the core during the lifetime of the board. Neither Polyurethane nor Expanded Polystyrene are particularly absorbent, the latter being the most impervious of the two. So unless the board is suffering severe delamination resulting in voids between the skin and foam and the exposure to water was long term (clearly not in this case), any water penetration is likely to have been limited to the immediate area around the plug.

Personally, as Ben1973 suggested, I would leave the board in the sun with the plug removed with a large-ish, clear polythene bag taped around the aperture but hanging off to one side. Any water that has penetrated should escape as condensation into the bag. If necessary, dry the inside of the bag and repeat that on several occasions noting how much water vapour condenses each time. It should reduce each time but I suspect is likely to be minimal in the first instance.

For your sake and that of your board, I hope I'm proven correct!

Select to expand quote

MrBlean said..>Neither Polyurethane nor Expanded Polystyrene are particularly absorbent, the latter being the most impervious of the two.

Sorry this is VERY incorrect, it's true that Urethane and extruded polystyrene are not absorbent bu expanded polystyrene, will suck water like crazy if the pressure inside the board is less than outside. Once in the board it will also travel with gravity, that's why when draining the vent/drain plug should be at the lowest point.

The only reason a vent plug is need is because it's not closed cell foam, and air can travel freely through the board, so if there's a weak spot, air will travel to it and cause a delamn.
This can't happen with closed cell foam, so it doesn't need to be vented.

If a board has a vent, it's almost certain it's open cell foam.

And lots of water can get in, without a delam

Select to expand quote

decrepit said..

MrBlean said..>Neither Polyurethane nor Expanded Polystyrene are particularly absorbent, the latter being the most impervious of the two.

Sorry this is VERY incorrect, it's true that Urethane and extruded polystyrene are not absorbent bu expanded polystyrene, will suck water like crazy if the pressure inside the board is less than outside. Once in the board it will also travel with gravity, that's why when draining the vent/drain plug should be at the lowest point.

The only reason a vent plug is need is because it's not closed cell foam, and air can travel freely through the board, so if there's a weak spot, air will travel to it and cause a delamn.
This can't happen with closed cell foam, so it doesn't need to be vented.

If a board has a vent, it's almost certain it's open cell foam.

And lots of water can get in, without a delam

Ageeed decrepit.,

leaving your board inside where sun can hit it a few hours a day for a month or 2 is the best method.

Friends use to own and operate a windsurfing center. One day a client dinged the nose of a board. Just spider web like fractures. Board was set out under the hot (+30C) sun. Bit of bubbling around the fracture. Several maybe an hour sessions of sun cooking later he sealed the damage. If significant amount of water penetrated into the core he noted eventually it might soften up. Then board surgery time. Not a heavy load area like the fin box, mast track, footstrap....

Similar damage on my board. Exact same model as the windsurf center board that was damaged. "Repaired" the same way. A couple years ago.

Nico Prien in an old video showed how one of his boards was professionally repaired. Damage looked like a considerable amount of water would have soaked in. If remembered correctly. A relatively large chunk of foam was removed and replaced.

Not sure if our boards have foam of the same chemistry as what some foam cored sailboat decks have. The wet foam tends to eventually "mold", change color to yellow/brown, and lose structure resulting in a soft deck. I can understand why the board repairman removed probably a larger volume of foam than what just looked damaged.

Wonder if a wet/dry shop vac develop enough suction to pull water.

Select to expand quote

OldGuy3 said.. >>>>>Wonder if a wet/dry shop vac develop enough suction to pull water.

Should do, you just need air flow, undo the bung, have damage at lowest point and seal the suction nozzle around the damage. You then get an airflow through the board from the bung to the damage. Don't need a huge amount of suction, but of course the more flow you have the quicker the operation will be.

Select to expand quote

segler said..
Oh heck no. Don't ever push air into a board. Risk of delaminating the skin. Always pull a vacuum.

no one said to seal it to the vent hole - just provide some small amount of air movement in that tiny little space you'll find there!

cutting the hose off at an angle will help prevent it from being plugged up by butting against foam etc. do this in combo with the strip of paper towel with its one end pushed through the vent hole and into foam using a thin blade screwdriver mebbe,..

be ready to give it time, couple weeks, or more,... depending. 16oz water = 1 american pound. how overweight do you think the board is? if imagine trying to evaporate a bottle of water with very limited small opening; this is essentially what you're trying to do but providing some bit of air movement will help.

this could take weeks but weigh the board before starting and every once in awhile later to see if it's losing weight, or basically done. use a cheap electronic 'fish scale' from amazon.

* to be clear,... use the scale to weigh the board and air pump to explode your board,... :D

fwiw - if you could get your vacuum sealed to the board, how many psi negative pressure do you think you could achieve? now, multiply that by the board's square inches of bottom surface to evaluate the type force you're putting on that board structure. lets say 2 psi negative pressure x 600 sq inch as a rough estimate,... :O

Remember the maximum pressure differental you can generate using a vacuum pump is 14.7psi. The lowest density beaded junk foam I have seen used in a board's core has a compressive strength around 20psi, so no need to regulate vacuum if the core is in cood shape.

I have collapsed a board using vacuum, but that board's core was a disintegrating mess of loose beads and dust, so the board wasn't worth saving.

Bad bad
Plenty of boards in good condition have collapsed with vacuum.