The impressive piece of technology that Shawn Gavin demonstrated recently at Forestville’s El Molino High School, the likes of which students hadn’t seen, was powered not by a featherweight lithium-ion battery but a 51-horsepower diesel engine.

Gavin’s device is 37 feet long and towed behind a beefy pickup. It lifts and turns large logs and precisely cuts them into slabs and timbers.

The Petaluman brought his portable sawmill to El Molino at the request of woodshop teacher Brian Phillips and parent Steve Griffith.

Gavin brought it to show Phillips’ students how wood from felled trees is cut and to answer their questions about his livelihood and his mill-on-wheels.

Sawdust flew as the rig’s 19-foot loop saw sliced through a redwood log more than 7 feet long and 3 feet in diameter. Gavin told the students his blades dull fairly quickly with hardwoods such as blue gum eucalyptus.

“Redwood is the easiest,” he said. “It’s like a hot knife through butter.”

The three large redwood logs came to El Molino as a donation from the Grab N’ Grow compost and mulch yard on Llano Road. They were awaiting the chipper when Griffith asked if he might use them at the high school.

Parmeter Logging & Excavation and Chase McClay loaded up and delivered the logs.

Phillips said that once the milled wood dries, students will use it for woodshop projects such as tables. He’s thinking a couple of redwood benches for the campus would be nice, too.

Chris Smith is at 707-521-5211 and chris.smith@pressdemocrat.com.