ability of the alloy to produce the smooth paste is substantially improved by rapidly cooling and mechanically working the casting the thixotropic paste flowed in response to hand applied pressure and retained its shape thereafter neither hot shorting nor eutectic bleed were observed a series of alloys were prepared for testing in accordance with the aforementioned preferred procedure to determine the effect of variation of the alloy composition on the formation of a spreadable paste in summary alloys containing less than about 10 weight percent cu formed excessive liquid phases and were difficult to handle an excessive liquid phase was indicated by eutectic bleeding or on panel running of the paste alloys containing greater than about 25 weight percent copper evidenced unacceptable brittleness in the paste that resulted in hot shorting hot shorting is typically found in pastes wherein the proportion of the solid phase to the liquid phase is too large sn cu alloys containing no zinc were difficult to work and frequently squeaked during application similar to the squeaking produced when sn metal is deformed at room temperature alloys containing less than about 1 0 weight percent zinc formed a paste over an extremely limited temperature range so that it was extremely difficult to control the paste properties during application alloys containing greater than about 7 5 weight percent zn also exhibited unacceptable hot shorting these results are shown graphically in the figure as the region a b c d alloys having compositions falling with the region a b c d formed suitable thixotropic pastes for body solder use within the region a b c d alloys having compositions falling within region e f g h formed preferred body solder pastes alloys within the.