members are welded together by indirect application of heat , as for welding internal battery posts for connecting groups of plates or terminal posts electrically , through the use of a plurality of heated elements simultaneously engaging posts to be welded together , and wherein the configuration of molten material is controlled as the weld cools , by the use of a templet . the elements are heated , preferably by application of open flame through a plurality of mixing systems for the fuel , with one system being provided for each heated element .