Log
A term of wide application in the foundry, meaning any piece of blocking-timber used for shoring purposes or as a bearing for flasks, etc. See TRESTLE.
Loosening-bar, or rapping-bar, is usually a round, pointed bar for jarring patterns previous to lifting off the cope or drawing out a pattern. In the first instance the jarring effects a separation of the sand from the pattern before the parts are separated with the view of preventing a bad lift; in the latter case the pattern is loosened and made to draw easier. Rapping-plates are, or should be, inserted in the pattern to receive the point of the bar, which is then struck in opposite directions with a hammer or sledge. See RAPPING-PLATE; LIFT.