a solder for filling or padding operations on automobile bodies , consisting essentially of 2 . 0 - 7 . 0 wt % antimony , optionally less than 5 . 0 wt % of tin and the balance of lead . this solder is inexpensive and exhibits good physical properties at high temperatures principally due to its high solidus temperature of above 240 ° c . the use of this solder is particularly advantageous when the filling or padding operations are preparatory to a surface coating operation in which a high baking temperature is employed for hardening enamel paint or varnish .