Crack in hull bottom
Posted: Wed Jul 04, 2018 12:20 am
There's a crack in the hull below the stuffing box. This area which is approx 40 cm deep by 15 cm wide bilge, fw of the stuffing box is holding the stuffing box dripwater has probably been full of water for many years. It had multiple gelcoat-deep small blisters, without acid.
Boat was scraped and dried for the past 7 months. A lot of work was done including on thru hulls and the stuffing box, boat repainted and launched yesterday. A leak was visible immediately at the bottom of that small deep bilge, under the the point where the shaft enters the stuffing box. Water was coming in at a slow rate and somehow it became slower throughout the day as the bilge was dried and the leak isolated
The boat was relifted the next day and some 25-30 cm long cracks were visible on both sides of the hull below the shaft, dripping bilge water out from a single point.
Without removing the shaft, access to this area on the inside is very limited. I can just touch the bilge bottom with my finger tips. There are just a few cm between the hull and the shaft and less between the hull and the stuffing box.
Would resin and fiber repair - dry, grind, sand, lay wet diagonal fabric - on the outside alone be sufficient to restore structural strength and stop water?
How far around the cracks should the repair extend?
The cracks were not there before the boat was put on the crane straps to be lowered back to the water and they appeared exactly below the aft strap. I have scraped, sanded and painted this area extensively and would have noticed them, however this section of the hull felt and sounded thinner, with light coming through, and small blisters. The boat was left on the straps for the weekend with all that weight on a now dry, compromised area of GRP.
How should this fix be done so the straps do not crack it again. I believe this is not a high stress area when sailing.

Westerly Conway ketch 1979
Your input is appreciated!
Boat was scraped and dried for the past 7 months. A lot of work was done including on thru hulls and the stuffing box, boat repainted and launched yesterday. A leak was visible immediately at the bottom of that small deep bilge, under the the point where the shaft enters the stuffing box. Water was coming in at a slow rate and somehow it became slower throughout the day as the bilge was dried and the leak isolated
The boat was relifted the next day and some 25-30 cm long cracks were visible on both sides of the hull below the shaft, dripping bilge water out from a single point.
Without removing the shaft, access to this area on the inside is very limited. I can just touch the bilge bottom with my finger tips. There are just a few cm between the hull and the shaft and less between the hull and the stuffing box.
Would resin and fiber repair - dry, grind, sand, lay wet diagonal fabric - on the outside alone be sufficient to restore structural strength and stop water?
How far around the cracks should the repair extend?
The cracks were not there before the boat was put on the crane straps to be lowered back to the water and they appeared exactly below the aft strap. I have scraped, sanded and painted this area extensively and would have noticed them, however this section of the hull felt and sounded thinner, with light coming through, and small blisters. The boat was left on the straps for the weekend with all that weight on a now dry, compromised area of GRP.
How should this fix be done so the straps do not crack it again. I believe this is not a high stress area when sailing.
Westerly Conway ketch 1979
Your input is appreciated!