NATIONAL CITY , Here at the Knight & Carver Yachtcenter, the world no longer revolves exclusively around boats.
Windmill blades have claimed space on the production floor.
Knight & Carver has found a lucrative sideline in refurbishing and strengthening blades for wind turbines , the ones that generate power on mountain passes and in other rural areas.
The 53-foot blades are the work of another manufacturer. They are 10 to 15 years old, and come from wind farms in Palm Springs, west Texas, Minnesota and Alberta.
They have ended up at the Port of San Diego because of a design flaw. After a decade or so, this model of blade develops a crack near its base, said Hugo Carver, a principal at Knight & Carver.
Once the crack proceeds far enough, it hits a place known informally as “the zipper.” From there the blade splits along its length, like a piece of celery breaking away from the rest of the stalk.
Each blade weighs one ton, and the biggest force on it is gravity, Carver said. With each complete rotation, the Earth’s pull will stretch a blade toward its tip, toward its leading edge, toward the windmill hub and toward the blade’s trailing edge.
Materials like metal will quickly fail under that stress, Carver said. Fiberglass has the needed flexibility.
Working under the direction of Project Manager Leo Martinez, crews first grind down the base where the crack forms. They perform the work under a plastic tent; gray dust sits several inches thick on the floor.
Crews then apply new fiberglass to the blade bases, put on a fresh coat of paint and add bolts to the bases. The one-ton blades are finished so they weigh within one-half pound of each other.
Carver calls it “recycling green power.”
Knight & Carver got into the work, technically known as “reformation,” four years ago at the request of an executive with a wind power company.
The windmill blades come in sets of three. So far the company has “reformed” close to 120 sets.
There are 2,500 sets out there, Carver said. A Spanish company is also at work reforming blades, but Carver said he knew of no domestic company working on such a project.
A new set of blades costs $100,000, Carver said, while he charges $15,000 to refurbish a set. Carver declined to give his margin, but said it is “excellent.”
“We like the business,” he said.
Leaders at the National City company would like to increase their work from 30 to 300 sets per year, and the company has the capacity to do it, Carver said.
The work is different from the custom yacht-building that goes on under the same roof.
While crews spend 300 man-hours to rework a set of windmill blades, a 70-foot, twin-screw diesel motor yacht in the next bay will need 60,000 man-hours before it’s ready for the customer, Carver said.
The production work of reforming the blades is a nice contrast to the work of building custom boats, Carver added.
Knight & Carver is also interested in getting into the blade-making business, he said.
Knight & Carver was founded in 1972. The company had facilities at Mission Bay and in the Sports Arena area before moving to National City.
The company occupies a 100,000-square-foot covered production facility and an outdoor boat repair yard. It employs 130 people