Thursday, April 30, 2009

Ferrocement Sailboat Construction

Ferrocement is one method of sailboat construction.
"This site is devoted to the promotion of Ferroboats as well as a base for all matters Ferro in the boating world. Ferro-cement is the name given by English speaking people to a boat building method using steel wires covered with a sand and cement plaster, patented in 1855 by the French, who called it Ferciment. Ferciment boats built before 1855 are still in existence and at least one is still afloat. The Italians called the method of construction Ferro-cemento. The British, New Zealanders and Canadians who promoted the method for amateur construction called it Ferro-cement, often referred to as "concrete". It is the cheapest and easiest form of construction for boats over 25 ft. And apart from strip-plank composite construction, it is the only viable material for large round-bilge boats within the amateur capability, without the requirements of special tools or a weather-proof building."

One man's labor of love (building a ferrocement boat): SEAFALCON.ORG

One bit of recent research regarding "Aluminum Bronze Alloy for Corrosion Resistant Rebar (link updated Aug 8, 2010)" might be of interest to those considering building a ferrocement sailboat:
This project evaluated aluminum bronze alloy as a possible alternative to steel for corrosion resistant concrete reinforcement. Rebars from aluminum bronze alloy were fabricated for laboratory and field evaluations. Initial tests showed rather low mechanical properties for alloys as compared to steel. Further work focused on improving the strength and mechanical properties of the alloy by optimizing its composition and fabrication process. The process eliminated the hot rolling operation and entailed direct continuous casting of aluminum bronze to a near net size and shape of rebar followed by cold drawing the bar to finished size and shape. The cold drawing operation increased the strength of aluminum bronze rebars close to that of mild steel rebar, meeting the ASTM specifications (Figure 1). In corrosion tests, the aluminum bronze alloy showed high resistance to seawater corrosion as compared to mild steel and ductile steel (Figure 2). Cost analysis of aluminum bronze rebars showed a cost of $0.85 per lb. as compared to $1.20 per lb. for stainless steel at current metal prices. The final report is available from the National Technical Information Service (NTIS # PB97-141972).

Sunday, April 26, 2009

San Juan Islands, Washington

wikipedia: San Juan Islands:
The San Juan Islands are a part of the San Juan Archipelago in the northwest corner of the continental United States. The archipelago is split into two groups of islands based on national sovereignty. San Juan Islands are part of the U.S. state of Washington, while the Gulf Islands are part of the Canadian province of British Columbia. There are over 450 islands in the entire archipelago at high tide, but fewer than one-sixth are permanently inhabited.

In the archipelago, fifteen islands are accessible by public ferry. Public ferries serve nine Gulf Islands and six San Juan Islands.

I have spent a little time in the San Juan's - those beautiful islands are enchanting, beguiling, and healing. One feels the stress of the hustle and bustle of life falling from one's shoulders as the minutes pass on a voyage from Anacortes Washington via the ferry...

A user-friendly guide to the San Juans:

San Juan Outfitters

Snug Harbor Marina Resort

Roche Harbor