When a friend first told Raymond Gray, the owner of A-1 Total Service Plumbing in Los Angeles, about the TCM 5000 drain cleaning machine made by GI Industries, he admits he was a little skeptical. That didn’t last long — just one job, in fact. And an ensuing revenue bump of about 20 percent over the last year or so certainly sealed the deal.The project entailed descaling and deburring a 16-inch-diameter, corrugated-metal stormwater drainline to prepare it for a fiberglass liner. Using some stiff brush attachments custom-made by GI Industries, the unit — known as the Merlin — cleaned the
