Sounds like you found one of the reasons why ferro boats are held in suspicion by so many folks, Wheels.
Mate! I was waiting for that :-)
Actually it is a common problem in FC and has nothing to do with hull
intergrety. This is an inside plaster finish issue. The plaster mix when applied is very dry. It is not a slurry. This is so you have little to no shrinkage when the hull
cures. But certain areas make the getting the plaster into, very difficult. For those that have built a few hulls, knowing those areas can exist and where thos areas are likely to be, ensure that thye either work harder at filling that area at time of plaster, or that attention is required shortly after the hull hardens. The experts even miss these areas at time of plaster. What makes them experts is to know where they will be and to fix them shortly after by introducing a slurry into the areas with a simple pump.
If I was building an FC hull today, I would be ensuring that intigral tanks
are fully sealed from the inside. But then, on many boats no matter what they are made of, I constantly see dumb ideas with tanks
and other things. Making them totaly impossible to get at.
What I have learn't
. If you are contemplating building a boat, ensure all tanks can be easily removed or have good access. Ensure all cables
are run through conduits or trays. Ensure all bilge
areas are easily accessed. Ensure you can get to the oil
drain on the engien sump easily.