People often tell me that they take a lot of care to be sure their hands are very clean when handling parts. But, what kind of contaminants remain on your hands, even after you have washed them thoroughly? Figure 1 shows that your hands will always have oil from your skin, perspiration (water, as well as body salts, perhaps slightly acidic, too), and electricity (yes, we are an electrical being as well). So, even if you thoroughly washed your hands just prior to brazing, then walked out to your brazing shop, by the time you got to the parts you were going to handle, your hands would once again have water, salt, acid, oil, electricity, etc., on its surface.
People have often told me: “Well, even if that is true, I don’t ever touch the actual brazing surfaces with my fingers.” If you believe that statement, then I have bridge I’d like to sell to you. People make mistakes, and I’ve often seen people touch critical brazing surfaces by mistake, even though they did not intend to do so. Therefore, it is important to always wear gloves when assembling parts for brazing!