ones. They dispense a fixed amount of filler metal to each joint. It takes the decision-making on the amount of filler metal to use out of the brazer’s control. They use wire rather than rod, which gives a slight cost savings. You do not mention the diameter of the braze rod you are using. The larger the diameter of braze rod, the more heat it takes to melt it and therefore get it into the joint. The extra amount of braze filler metal also sets you up to use too much as it is difficult to control a large amount of molten metal when you are trying to get it into a tight joint. We worked with a manufacturer to convert from a 2.4-mm- (0.093-in.-) diameter rod to a 1.6-mm- (0.062-in.-) diameter rod. It experienced a 30% drop in braze filler metal usage. Heating times were also reduced. An additional thing to try is using flat cross-section braze rods rather than round rods. Some operators find it is easier to hit a spot on a tubular braze joint with a flat rod rather than with a round rod. This is particularly true on smaller joints. These flat rods are readily available. In almost every case, by taking steps to reduce filler metal usage, you should enjoy additional benefits like reductions in energy costs, less rework, increased productivity, and better aesthetics. It is a good place to focus improvement efforts. For info, go to aws.org/adindex For info, go to aws.org/adindex 28 WELDING JOURNAL / JUNE 2016 WJ This column is written sequentially by TIM P. HIRTHE, ALEXANDER E. SHAPIRO, and DAN KAY. Hirthe and Shapiro are members of and Kay is an advisor to the C3 Committee on Brazing and Soldering. All three have contributed to the 5th edition of AWS Brazing Handbook. Hirthe (timhirthe@aol.com) currently serves as a BSMC vice chair and owns his own consulting business. Shapiro (ashapiro@titaniumbrazing. com) is brazing products manager at Titanium Brazing, Inc., Columbus, Ohio. Kay (Dan@kaybrazing.com), with 40 years of experience in the industry, operates his own brazing training and consulting business. Readers are requested to post their questions for use in this column on the Brazing Forum section of the BSMC website brazingandsoldering.com.
Welding Journal | June 2016
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