On grinding some tiny blisters back to make it easier to fill I discovered the boat was rife with osmosis. When the small blisters are carefully ground back a much larger area of dried out glass is revealed. One particularly bad bit had to be ground right back the last inside layer before unaffected glass was found (I put 6 layers of new glass back in before finishing with filler). The boat has been on the hard for nearly three years and so the moister has completely dried out which is good and what would have been proud blisters have actually shrunk back flat making detection quit difficult. But every tiny little hairline crack only 3mm to 5mm long has revealed dried out glass below, I've upload some pics so you can see the extent and how small the blisters are compared to the damage below the gel coat. I've had two sessions now and have decided enough is enough so have purchased some epoxy undercoat which will be going on shortly. Any more osmosis can be sorted in a few years time if it reveals itself.
Skykomish E29 says:
Achilles are not known for any Osmosis problems usually but then I suppose they are getting on a bit now and so as with anything the passage of time takes it;s toll.