Part of the integral strength and waterproofing is the saturation of the woven glass with resin, if the glass fibres are broken then eventually the top coat/ gloss coat will fracture along the cracks and water will penetrate.
If you sand down theatre cracks in the weave will be exposed and only a thin layer gloss coat will be on top..
I have repaired with a wider than cracked area sand back and another layer of glass mat and a new gloss coat .
Adds weight to the board, could be problem is too much weight on the nose.
How do you tell if water is getting in?
Discoloration, feels heavier Do a lip,suck on the cracks if you draw water, it’s in!
Oh and flex marks are less from impact ( that usually is shatters from the point of impact).
And yep,they are flex marks, can also be a result of light glassing
Stress marks come from the board being forced into a flexed position by the wave pushing down . Usually directly across the board at the point where it was
Often boards labeled performance can suffer from extra light glassing
Look too on your board for early heel dents and sinking along the stringer which would show a lesser density foam blank.
Hmmmm ?
Hope you find no,other problems
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