Full osmosis removal and repairs on a boat

Boat osmosis or boat cancer is a concern when found.
In plain English - osmosis is the ingress of water which becomes trapped between fibreglass layers causing the fibreglass to blister.
In mild cases, the blisters can be sanded back and repaired.
In severe cases, a whole layer of fibreglass needs to be ground off, and new fibreglass put back.

[@boatdetective]

Disbond between the matt skin and the underlying laminate is not unusual. It certainly wasn't caused by blistering. Whoever conned the owner into planing this boat down made a bad call.

[@nedtalksship]

Thanks for your feedback. Just to fill in some blanks - we did a lot of work with boat builders to assess the situation and we were able to present multiple options for correction to the owner - one of them being to plan back the hull. The owner we were working with chose this option - as he wanted his boat's hull to be perfect.

[@markbailey6051]

Stop the madness and just paint the bottom. No boat has ever sank from blisters. Planning the structure because of blisters will weaken hull and make the boat hull questionable.

[@billwallenstein3387]

How much does it cost approximately to repair a bottom like that? Per foot? Cleaning, sanding back, re gel coating, apply new anti fowling. total cost

[@nedtalksship]

Hi Bill - the cost would vary depending on the boat and the severity of the osmosis. I cant really answer your question

[@AustinSwill]

wow, what a project, what did that cost?

[@nedtalksship]

This is not a cheap process. It normally costs upwards of $20,000 - depending on the size of the boat and the depth of the osmosis.