Severe cracks each end of keel box under hull and mid cracking on Sailfish 25

[littledancersadhu]

Built in 1980, is it time to drop out the keel, take down the mast to preserve this yacht and use her as a slow cruiser.
Repair of the hull would be very substantial.

Thoughts

 

[veshengro]

Severe cracks​

I would think that even as a "Slow cruiser" you should ensure the complete integrity of the underwater hull. Even if you potter about with just an engine you might still encounter something other than glassy seas, even a heavy wash will make her hull work.
Can you get to the cracks easily to at least do a decent if non professional repair before you venture anywhere out of wading depth?

 

[littledancersadhu]

Yes, looking at dropping out the keel, grinding back to good fibreglass and reinforcing, only taking the boat across our small shallow bay.

 

[veshengro]

Understood. I've seen small inshore working fishing boats with some pretty gruesome amateur fibre glass repairs to their hulls, so if you make a good job of it and stay in shallow sheltered waters you may get away with a good solid repair. Don't spend too much money on it, but give it a go, I would. If not successful then you haven't lost much.

 

[William_H]

I am not sure what type of lift keel the Sunfish has. However the keel box will take the sideways load of the keel. Both water pressure and righting force. It should be practical to reinforce the keel box. Firstly on the outside of the hull with a build up of cloth and resin all faired in. Consider kevlar or carbon fibre for more strength with thinner built up. But mostly reinforce the keel box on the inside. Support at the top of the keel box would be most effective. Consider build up of structure hull to box at front and back and sideways support.
The vertical drop keel box on my 21 fter has posts at the front and rear going up top the cabin top. The front one doubling as mast support. The 2 together also taking load of lift tackle. But also providing support for the keel via the box taking loads to the cabin top with great leverage.
Even on a dinghy it is usual to have a thwart from one side of keel box to the gunwhale on each side.
So I wonder if keel box was damaged by keel hitting a rock at speed or if the design was simply inadequate long term sailing. ol'will

 

[littledancersadhu]

I am not sure what type of lift keel the Sunfish has. However the keel box will take the sideways load of the keel. Both water pressure and righting force. It should be practical to reinforce the keel box. Firstly on the outside of the hull with a build up of cloth and resin all faired in. Consider kevlar or carbon fibre for more strength with thinner built up. But mostly reinforce the keel box on the inside. Support at the top of the keel box would be most effective. Consider build up of structure hull to box at front and back and sideways support.
The vertical drop keel box on my 21 fter has posts at the front and rear going up top the cabin top. The front one doubling as mast support. The 2 together also taking load of lift tackle. But also providing support for the keel via the box taking loads to the cabin top with great leverage.
Even on a dinghy it is usual to have a thwart from one side of keel box to the gunwhale on each side.
So I wonder if keel box was damaged by keel hitting a rock at speed or if the design was simply inadequate long term sailing. ol'will

Had all the flooring up and all the panels of the side of the keel box today, scraped cleaned and looked for any sign of cracking around the keel box. not even 1 hair line crack, everything looks absolutely solid. must be the gel coat.
Dropping the keel out this year, for a intimate inspection, and keel paint overhaul.

 

[Refueler]

I am completing the repair of cracked bilge keel joint to hull ...

Its worth grinding back into strata under the Gel coat cracks .. the Gel has cracked for a reason ... it may not be cracked on inside - most boats don't have gel on inside - so the laminated strata gives a little without cracking any gel.

Resin / Matt both inside and out is order of the day for my keel ...

For OP - I would actually be inclined to keep the lift keel installed once repairs made ... its weight and stability part of design.

 

[littledancersadhu]

I hear you, thank you for the information, boats, who'd have em eh! Constant fixing!!! Love it!

 

[littledancersadhu]

Wrong turn?

 

[littledancersadhu]

This is SADHU my sailboat in havre des pas swimming pool, a great memmory for my daughters whom were aboard at the time.

 

[neil_s]

Lift keel boats get to places others can't!