Before we even entered the panel exposure area, John pointed out that many surfaces that we could see surrounding the farmhouse building were also being tested. This included the asphalt walkway and footbridge next to the building, another coated walkway alongside the building, and the concrete roof tiles on part of the farmhouse. Even inside the panel test site I could see that no surface area was wasted – panels were being tested on the underside of some of the testing rack soffits.
Testing at this site is done with all kinds of paints on a variety of substrates, including metal, wood, concrete, vinyl siding, stucco tiles and PVC pipe. On average, panels undergo exposure testing for three to four years, however the site contains panels from every decade for the past 50 years. The oldest, a green, wood panel from 1954, was painted with the first all-acrylic exterior coating and looked amazingly new compared to many of the samples surrounding it. I found it interesting that panels are labeled the same way today as they were 50 years ago: a series number that shows the year and the sequential order of the collection of paints and panels exposed together; a letter to indicate the substrate (e.g., Y for yellow pine); a number indicating the number of months it has been weathered (Y3 = 3 month weathered yellow pine); and numbers to represent the paints and the number of coats added. Panel readers today can look at some of the first boards ever tested and know exactly what was done, and what the results show. In addition to this traditional labeling system, each series of panels at DCM’s exposure site is given an RFID tag, which stores all of the critical information and data regarding the series.
Unique to this testing facility is DCM’s patented eXposure Vision™ digital imaging and analysis system, which was developed by two Dow scientists and employs an automated, six-camera system coupled with software algorithms to measure and rate key exterior performance characteristics, from cracks to flaking and tint retention to yellowing. John pointed out that of the 200 readings that take place, the majority are still done by highly trained panel readers. Currently, about a dozen of the readings are done on eXposure Vision, with more readings being added as they become available.
To build upon eXposure Vision, DCM launched eXposure Vision Viewer last May, an online system that puts exposure station test panels within easy view for customers. Through a secured log-in Web site, the system gives Dow customers access to test panel images in high resolution. In addition to tracking their own test formulations, customers can use the system to monitor the performance of new Dow products. North and south views are updated quarterly, and 45° south views are updated bi-monthly. All views are archived for future reference and comparison. Plans are underway to expand this capability to all key global exposure testing sites.
Thanks again to John and Dave for the fascinating tour. I really enjoyed seeing the history of panel exposure testing blend with the cutting-edge technology available today.