I suspect my Dyno 105 is taking on water and not sure where or why.

Diagnostics

1. I weighed the board and it is 400g (9.1kg) heavier than last time I weighed it (8.7 kg) 18 months ago. I weighed it back then because it felt "heavy". Advertised weight is 7.7kg. Noting that my Dyno 85 is 200g heavier than the advertised weight (7.4kg vs 7.2kg). So I suspect it was taking water even 18 months ago.

2. I store the board upright and it felt heavier at the back. So I stored it for a week at an angle nose down and now it is front heavy.

So definitely seem like it has water on board.

Any advice on how to get the water out (noting it has one of the Goretex plugs) and how to find the source of the water ingress?

Possible root causes

I did hit a rock with the fin at Pelican Point in January 2023, however I cannot see any damage around the fin box.

Any suggestions from the brain's trust welcome.

Drill a small hole in the nose and stand it up nose down for a couple of weeks to drain. After a couple of weeks then give it a few goes in the sun. Like half hour. Then weigh it. See where it's at.

In the meantime, could be the vent has failed. Could be a split under the pads so also check for soft spots or delam.

usually when leaving the board in the sun a small amount of water will trickle out of a split and leave salt trails. Have a look for dried salt residue around fin boxes.

you can definitely fix these things but in my experience the weight gain from the damage and the repair means the board will never return to original weight end I end up replacing the board.

Give it a wash with fresh water so there is no salt residue
Then get it in the sun (when you can find some!), and after an hour or two have a look for where water is coming out (water or salt crystallization around a tiny crack)

Helps to remove the goretex breather and seal the hole with a bolt and o-ring.

Then if none of that works, same thing but only doing the footstrap inserts with some detergent in the water and look for bubbles

I am tipping cracked powerbox as it can be realllly hard to see

Oh and stop moving the water around its easier to get it out where it came in and before it spreads everywhere

Happy to do it for u ....

Mark
MOzCustoms

I'm thinking fin box.
Could be an inner cracked box.
Squash some plastasine putty or plugs or something like this to seal the fin bolt hole.
On a sunny day put the board out in the sun , from in the shade bottom side up . Fill the box with water. If the box is cracked , you will see bubbles straight away. That will tell you if the box needs replacing.
ps, I'm just thinking , if you tilt the board one way and it gets heavy that way , then tilt it the other way and it does the same..sounds like dodgy very pourous foam to me. Slo mo , sloshing from one side to the other sounds very wrong.
EPS is made with sand sized beads that are expanded in a mould. The more beads , the heavier the foam.
Closed cell foam beads don't soak water , the gaps between do. Pour water on a beanbag and the water will pour out the bottom. EPS foam is formed under pressure. The higher the pressure, the smaller the gaps between the beads and the size of the beads. Good quality EPS has almost no voids. Such as crab pot floats. A less dense foam will let water flow between the beads. It's a weight thing. Light foam will have bigger balls and gaps. Heavier foam , the opposite.
With windsurf boards , the lighter the better , until it becomes a beanbag.
Im thinking this is going on to save 200 gm.

One caveat about the "look where the water comes out" test: I had a problem with a board that also slowly took on water over a year. When I finally put it into the sun after taking it out of the (hot) trailer, I saw water dripping out at multiple tiny little cracks in the paint on one side. There also was water coming out near the center foot strap plugs (which were tightly surrounded by EVA padding).

When I eventually removed the EVA pad, the problem became obvious: poorly inserted foot strap plugs, with lots of empty space around them. Most likely, the epoxy used when putting the plugs in got too hot, and melted the EPS next to the straps. This was clearly where the water got in. I had noticed some water pooling around the plugs several times before, but had assumed that it was used from the EPA (I bought the board new and never even put foot straps on the board, so screws that were to long were definitely not the cause).

My take is that the board was so soaked in water over time (1 kg over specs) that eventually when it heated up, the water vapor created so much pressure that the water escaped at every little chip in the paint. Those chips were so small that I'd usually ignore them, I never had problems with tiny little paint cracks like that. So it's possible that when you see spots where water comes out, it may not be the only or primary spot of water entry, which may be hidden. My board was a cheap construction, and secondary "outlet" points may be less of an issue if the board has full sandwich construction - but it sounds like there's even more water in your board.

I'd also be concerned about putting a board full of water straight into the sun. Recipe for delam if it hasn't happened already.

Select to expand quote

Gestalt said..
I'd also be concerned about putting a board full of water straight into the sun. Recipe for delam if it hasn't happened already.

I'd say it almost certainly HAS happened already. The water migrating so readily from tail to nose suggests that it's not working its way through the foam but between foam and skin.