Buying advice - Survey showed excessive moisture below waterline

[neilpride]

It does not take 4 days, peel a small window free of antifouling, gelcoat does not pick up moisture, if there is moisture measuring on top of gelcoat, it is moisture in the laminate.

[boatpoker]

Originally Posted by neilpride

It does not take 4 days, peel a small window free of antifouling, gelcoat does not pick up moisture, if there is moisture measuring on top of gelcoat, it is moisture in the laminate.

I have seen dozens of boats with blistered gelcoat )due to absorbing water) and no moisture in the laminate or even the skinout mat.

[neilpride]

Originally Posted by boatpoker

I have seen dozens of boats with blistered gelcoat )due to absorbing water) and no moisture in the laminate or even the skinout mat.

Many times, those hundreds of small blisters appearing in the gelcoat are osmotic.
Pressure.
Pick a piece of cured gelcoat and submerge it in water for a few days.

It is an inert pigmented resin sheet, the problem is when it allows water to pass through capillary action , or cracks into the laminate.

[boatpoker]

Originally Posted by neilpride

Many times, those hundreds of small blisters appearing in the gelcoat are osmotic.
Pressure.
Pick a piece of cured gelcoat and submerge it in water for a few days.

It is an inert pigmented resin sheet, the problem is when it allows water to pass through capillary action , or cracks into the laminate.

Gelcoat is simply a pigmented resin. Polyester is hygroscopic and does absorb moisture as does vinylester but to a lesser degree.