The router used is a connnercial model equipped with a 5/16-inch-diameter 

 (7.9 millimeters) carbide bit. The only modification necessary to the router 

 is the addition of a metal guide bolted directly to the router baseplate Csee 

 Fig. A-1) . It is important to use only carbide bits as ordinary steel bits 

 are not adequate for cutting some liners and quickly become dull due to sedi- 

 ment abrasion. Circular saws previously were tried to cut the liners but they 

 did not prove as good as a router, 



METHODS ; In use the core is placed in the trough and its elevation adjusted 

 by inserting pl3rwood spacers beneath the core so that the top of the liner is 

 slightly below the top level of the trough sides. The router is then set on 

 top of the trough angles and the bit adjusted to cut only the liner and not 

 disturb the core. The guide is set so that the router will ride along one side 

 of the trough, and keeping the bit on the centerline, the router is guided along 

 the trough, making a longitudinal cut through the liner. The core is then ro- 

 tated 180° and a second cut made. Once the liner is cut the core must be taped 

 or held together when removed from the trough. The core is then moved to the 

 table where a complete splitting of the sediment core is accomplished using a 

 knife or wire. 



