Arnold J Lee

US Patent:

20030140950, Jul 31, 2003

Filed:

Jan 29, 2002

Appl. No.:

10/057997

Inventors:

Yang Kim - Hayward CA, US
Eugene Oak - Los Angeles CA, US
Arnold Lee - Castro Valley CA, US

International Classification:

B08B007/00

US Classification:

134/038000

Abstract:

A method is invented to remove lead based paint from a large outdoor steel structure without emission of the lead fragments to the environment. The method of this invention protects the surroundings from contamination by the lead contained in the paint material. The method of this invention utilizes the different thermal expansion coefficients of the paint and the steel structure. Adhesive materials, including but not limited to, epoxy resin monomers, sand particles, grout, are added on the surface of an existing lead based paint layer. A protection layer, including but not limited to a paper and fabrics, is laid on the top of the slurry to soak the monomers in. The epoxy resin is cured firmly by proper activator of, including but not limited to, heat and peroxide. Liquid nitrogen, which is supplied through a rubber hose, is sprayed on the surface of protection layer of, including but not limited to, a “Chang Ho Ji” paper. As the temperature of the composite layer decreases, the volume of the steel layer and the composite paint layer shrink drastically differently to separate the paint layer from the steel surface. The composite paint layer, separated from the steel surface, is ripped off from the steel structure and collected as the temperature reaches back to ambient. Lead, which was contained in the paint, is recovered safely without being blown into the air eventually contaminating the surface water.