Some Like It Hot Page 3
Some things were clear, though: At one point, the individual blocks of coring were visible, the temperature of the core itself different from that of the adjacent filler. Solid areas of the hull were also obvious, such as around through-hull fittings, as were long-forgotten repairs. We saw no delamination, no large voids, no resin-starved areas—but, ominously, along the keel for the aft two-thirds of the boat's length was a dark patch, signifying water in the sandwich. Ashton said he'd recommend cutting a couple of samples from this area to see precisely what was going on and to help in planning the repair. Using the report from our investigation, the hull was evacuated of moisture and infused with resin to fill the area the moisture had occupied. The hull was then reevaluated with the IR camera to ensure the repair was complete.
Interpreting IR images takes training and practice. Ashton is a SAMS-accredited marine surveyor and holds a Level I thermographer certification from the Infrared Training Center (ITC) in North Billerica, Massachusetts, a subsidiary of FLIR Systems, manufacturers of IR cameras. The ITC gives its Level I course in many cities throughout the U.S. and Canada; it covers the fundamentals of IR thermography, but it isn't a basic course. During the four-day program, students learn the principles of thermal science, heat transfer, and infrared science, along with electrical, mechanical, and building applications of thermography. According to ITC director Bob Madding, although "a couple of handfuls" of marine surveyors have reached Level I certification, there isn't enough demand, yet, for a specific course. However, he adds, marine surveying uses many of the same principles as thermography of buildings and electrical systems. "You have to know as much about what you're looking at as what you're looking at it with," he says; it's easier to teach an experienced marine surveyor how to incorporate an IR camera into his practice than it is to teach a camera expert how to be a surveyor. But, Madding adds, there are lots of applications for IR imaging for marinas, service providers, and even yacht owners. Thermography is a great tool not only for surveying hulls, but also for troubleshooting electrical problems, monitoring heat-exchanger and turbocharger temperatures, or even checking the condition of shore cords and plugs.
Thermography is just too cool a 21st-century technology to ignore. Once the prices come down (Ashton's camera cost about $15,000), as I expect they will, every serious surveyor will have an IR camera in his bag, and no client will accept a survey report without lots of colorful infrared images. Today it'll take some searching to find a surveyor with thermographic capabilities (see contact information below for SAMS), but if your boat needs a thorough inspection with minimal application of the hole saw, you'll find it worth the effort.
Independent Marine Systems
Society of Accredited Marine Surveyors
This article originally appeared in the September 2006 issue of Power & Motoryacht magazine.