Ferro Hull Repairs

Ferro Hull Repairs


Hi, I am considering the purchase of an unfinished ferro yacht. This hull is over 20 years old and has never been in the water. The problem is there are large areas of mesh showing on the surface of the hull. I don,t know if this is from the plaser job or has been sand blasted. When reading your forum I lern that this will cause major discoloration problems to the hull finnish. What would your recomendations be as to repairing this. I have sent a couple of pictures also.


Gerald Roos...kangaroo@xtra.co.nz

Hi Gerald, seems like it is a fairly well made hull. After 20 years exposed to the elements there is no obvious deterioration. The steel matrix was probably only thinly covered as is often the case with good plasterers (should only be skimmed about 1/16" over top of mesh). You get a few areas where the mesh starts to grin though after a few years when the hull is not sealed, if the galvanising was scraped by a trowel. When you come to paint and prepare the hull, remove the rust first with a rust inhibitor, and then make sure you seal well with your primer preparation (remember most paint systems are porous). After 20 years a defective plaster mix would have reared it's ugly head by now.

Colin Brookes...colb@xtra.co.nz

Do you recommend skimming a plaster coat over top of the places where the mesh is showing then seal it up. Just treating the rust then sealing and painting over it.

Gerald Roos...kangaroo@xtra.co.nz

Hi Gerald, you can't skim a layer of plaster over it, it won't properly key and will eventually flake and drop off. Treat the rust and seal it, then you can use an epoxy filler to skim and level off before finishing and painting.

Colin Brookes..colb@xtra.co.nz

Want to know more about Ferrocement?

The information and comments given on this 'World Of Ferroboats', website are based on first-hand experience gained by the contributors over many years of use, designing, surveying, building and repairing ferro-cement boats.