Maxam MCO® (Maxam Composite Overlay) Passes High Alkalinity Resistance Test with Flying Colors September 19, 2006. Recently completed tests by a major U.S. plywood/forming panel manufacturer demonstrated that MCO® (Maxam Composite Overlay) is highly resistant to the extreme alkalinity and aggressive aggregates (e.g., black ash slag) that are typical of the new generation of high performing concrete mixes, and which are proving to be very damaging to HDO/MDO facings. The APA "Abrasion Resistance After Chemical Exposure" tests were used. In these tests, MCO® was subjected to the high alkalinity for 30 hours. A Tabor Abrasion Test then was employed to measure the performance of the MCO®. This company reported that, when they stopped the test after nearly 1,100 abrasion cycles, MCO® tested 4 times better than the highest quality HDO currently employed in the construction industry, and that they expected MCO® to be at least 6 to 7 times better than the standard HDO. These results are significant. Back to News & Events