The path from research and development to the market can be a long and circuitous one. While at the annual meeting of the American Institute for Conservation in Miami, I was delighted to have the opportunity to see a presentation on Bronze Shield, a product that we the result of research undertaken at North Dakota State University (NDSU) with funding from NCPTT. Click here to see the grant report.
The product is now manufactured and marketed by Elinor Specialty coatings. Dante Battocchi is the chemist and driving force behind Elinor Specialty Coatings and worked on the polymers at NDSU. He has attended annual meetings of the American Institute for Conservation and listened to conservators about their treatment needs. He knows that outdoor bronze treatments require a coating that provides good protection but can be easily removed. Also, the coating system must not alter the appearance of the bronze.
Bronze corrosion has been an issue since the industrial revolution. It is frequently the result of pollutants in the air – particularly sulfur dioxide and other pollutants that result from burning fossil fuels. A protective coating must serve as a barrier against water, oxygen, or other ions. The coating must be easy to apply, meet with environmental standards, resists UV deterioration and more.
Researchers at NDSU developed more than 400 different resins using combinatorial methods and automated synthesis. They then screened these resins based on three factors, (1) weather resistance and protection, (2) appearance, and (3) removability. For removability, the researchers built polymer systems that could be removed with a base solution.
After formulation of the polyester urethane-based product, Battocchi and his colleagues tested the polymer system in both laboratory tests and outdoor tests. They compared Bronze Shield with Incralac, a commonly used conservation treatment. They used standard tests and accelerated aging in the lab. They also tested the products in outdoors Fargo North Dakota for 23 months and in Loveland Colorado for 12 months. The product has also been field tested by conservators. Bronze Shield out-performed Incralac in every situation. The Bronze Shield is now available on the market.
Disclaimer: This product was developed under a grant from the National Center for Preservation Technology and Training, a unit of the National Park Service. It is solely the responsibility of the authors and does not necessarily represent a endorsement of the National Park Service or the National Center for Preservation Technology and Training.