I'm looking at buying an 80-foot ferrocement sailboat. She needs a lot of internal work, but she seems structurally sound. She was built in 1979 and has not been used in about four years, the owners have not had the money to keep her going. She rests unused at dock. When I checked her out I was rather surprised to hear that she was made of cement. I am in the process of researching ferrocement as a hull building material. I have found very little evidence to suggest that it is a good material for the purpose. Though I have found that good ferrocement vessels are not unheard of. Does her age possibly reflect her quality? Is there any way to inspect the hull to fing out how good it is? What are your recommendations? She was originally used for sail charters and I hope to use her for that purpose once more.
Dan Dickison responds:
Sue and Larry, two of our most active contributors, recently responded to an inquiry about what material is best for hulls: specifically, steel, wood, or fiberglass. After we posted their response, one well-meaning proponent of ferrocement hulls pointed out that we missed an opportunity to correct some myths about his preferred choice of boatbuilding material. This person was keen to point out that in general, ferrocement vessels are judged on the worst executions of those boats afloat. Indeed, some successful boats have been rendered in ferrocement, and the good news is that most of these projects are custom-built, one-off boats that presumably have been the recipients of more attention than is given to the usual production-built boat.
Though none of us here at SailNet are big fans of ferrocement, we think that you can find good boats built of that material. Regarding the age of the boat, I wouldn't be too concerned about that as a factor. Of course age relates directly to the kind of care that a vessel has received and the way it was constructed in the first place. Keep in mind that a well-maintained older boat will look and sometimes perform better than a neglected newer boat. However, if the internal steel structure that reinforces the cement has been compromised and allowed to rust, you will experience problems.
Since the boat that you're considering is so large, it's apt to represent a sizable investment, so we think it's only prudent for you to hire a qualified marine surveyor and get that person's professional opinion. If the boat were a 25 footer, we'd be more inclined to have you take our opinion and leave it at that, but in this case you should certainly seek professional advice. Here's hoping that things work out with this boat, but taking a cautious approach certainly won't hurt.