When the Tumbling Barrel IS the part...

Question: The part is the barrel itself. It is a 12" diameter pipe that has an inner coating of ~2mm that needs to be removed. The material to be removed has a Shore D hardness rating of 80. The pipe can be sealed at each end and rotated if a liquid would be required. What type of tumbling media and procedure should be used to remove that ~2mm inner coating?

Response: This can be achieved by filling the pipe with tumbling media almost half way. The media recommendation is a 1" x 1" or 1-1/2" x 1-1/2" KXF Cylindrical Wedge Ceramic Media. This is an extra fast cutting bond that can abrade hard metals. The process can be sped up by adding some 60 Mesh Silicon Carbide Grit to the load (about 1/4 to 1/2 lb per gallon of water). The water level should just cover the media load. A 12" diameter pipe should be rotated 30-45 RPM. The running time may take anywhere from 8 hrs to an overnight run.

{Summarized from a post on the ShopTalk Forum.}