Solvent Vacuum Cleaning and Surface Preparation Before a Vacuum Brazing Process

Abstract The vacuum brazing process has significant advantages compared to atmospheric brazing processes. Especially the fluxfree joining is a big benefit because removing flux after the brazing process is almost impossible. To reach the highest quality standards of the final product, the cleaning process prior to the brazing process is essential. Using a modified alcohol as a cleaning agent in a cleaning machine running under vacuum allows the solvent to reach cleaning temperatures much higher than its flash point. This causes perfect cleaning results with high surface tension as well as best drying results before the parts leave the cleaning machine after the cleaning process. This paper will explain the solvent cleaning process under vacuum, the cleaning effect, testing options, healthy, safety and environmental issues and case studies showing good and bad cleaning results.