Mildew Resistance in Wood Coatings
By Bernie Bottens | Posted: 03/08/2012 10:00AM
M.L. Campbell introduced an addition to their rugged EuroX line of exterior coatings. Their Euro line consists of European technology two component polyurethanes in both solvent and water-borne varieties. To look at the specs for these products, visit www.mlcampbell.com and click on the Euro products tab. That will lead you where you need to go. There are some new additions to that line this year, including their Euro X Water Borne Nanotechnology System.
Composed of a water borne exterior clear coat and a water borne impregnating stain, the first layer is a spray stain that may be tipped out with a brush as needed prior to drying. Special tinters are used and are necessary to create the colors and UV protection. A minimum of 5% and a maximum of 12% pigment load by weight are needed to properly protect the exterior coating system in conjunction with the mildew resistant additive found in the stain base. These additives actually help make the EuroX Water Borne Impregnating Stain and EuroX Water Borne Clear dry film mildew resistant. The pigments help to protect the wood from the sun’s rays. There are eight “standard” color formulas for the stain with other combinations possible.
The impregnating stain must be applied in concert with the water borne clear satin topcoat. In this case, a single-component European
|Last Week Bernie talked about new cabinet hardware from Berenson with antimicrobial finishes.|
technology clear designed for good flexibility, adhesion and protection against UV rays. Specifically targeted for exterior entry doors, garage doors, exterior joinery, shutters, and window trim, its forte is uses where a long lasting coating system and protection are crucial to the beauty of the wood. Architects and designers will want to pay special note to this system.
The way I understand it, this clear layer of coating is not unlike TYVEK or GORE-TEX cloth and is, at the same time, revolutionary. Water droplets hit its surface and simply slough off. However, should moisture somehow penetrate the wood, instead of being trapped there, collecting there, and eventually lifting the coating, the coating allows water vapor to pass back through the coating. Thus, the wood is fully protected from the elements, destruction of the coating via “lifting” is reduced.
We all know that no matter how carefully we coat the wood, water will still seek some opportunity to pass. After all, it’s wood. It constantly moves and adjusts to its environment. That is doubly true in the exterior environment. I think that you can see the possible advantages of this system for exterior architectural use.
About the Author
Bernie BottensBernie Bottens (WoodworkingNetwork.com/blogs)writes and teaches on the subject of wood and wood finishing in industrial woodworking. He and his wife, Carol, live in Vancouver, WA. Bernie has been teaching wood finishing to shop owners, shop foremen, spray technicians and finishers all over Oregon, southwest Washington, and northern California for the past 9 years. Prior to that, he owned his own cabinet shop. His shop credentials include apprenticing and becoming a journeyman exhibit builder. Before that he taught in the public schools for 20 years. Bernie is the owner of Kapellmeister Enterprises, Inc. and Kap Coatings Consulting. Reach him at firstname.lastname@example.org.