Chemical stripping is generally undertaken by one of two methods. The primary method and that most widely used in the metal recovery industry is via a Methylene Chloride process. This chemical is very aggressive and is able to remove most surface coatings but can also attack the base substrate. As the time taken to remove the applied coating varies according to its thickness the component substrate is placed at risk once the coating is removed.
Where steel is stripped by Methylene Chloride it will immediately rust and any processing of steel through this route will require subsequent de-rusting and oiling to protect its integrity. Equally due to its highly acidic nature, Methylene Chloride is subject to high health and safety risks and requires suitable training and supervision in use. In confined areas without extraction the Methylene Chloride vapour can be lethal.
For these reasons we prefer to use less aggressive Benzyl Alcohol chemical stripper which acts by dissolving the applied coating and holding it in particulate suspension within the chemical processing tank. This particulate build up is fed through filter presses which remove the powder and thus continually refine the chemical.
The benefit of using Benzyl Alcohol is that once the coating is removed, the process stops. This leaves the part free of applied coating but with a previously applied pre-treatment layer intact eliminating the possibility of substrate attack and corrosion. This process is therefore of particular benefit when processing high value castings or components subject to cosmetic quality parameters.
Unlike Methylene Chloride there is little environmental risk associated with Benzyl Alcohol and effluent control is not problematic