Laser Cleaning San Francisco Cable Cars

Carbon steel looks scabby with outdoor rust before work starts. Afterward the operator has bare iron that is still sound, without a pit track.

Cast iron arrives under rust and foundry scale. After the pass those films are gone and the graphite stays in the metal, not blasted out of the face.

Iron arrives under rust and mill scale that hide the face. After the pass those films are gone and the metal is bare, not abrasive-blasted or pitted.

Tool steel dies look filmed and oxidized before work starts. Afterward the operator has a still-hard working land without a blue temper stain.

Basalt monuments look sooty and dull at the start. Once the operator stops, the black rock is clean, not shiny-melted or split down a seam.

Cement walls look stained and dusty at the start. A stopped pass leaves the gray matrix, not a scorched or powdered crust beside the joint.

Hastelloy welds look stained and dull before work. A stopped pass takes the stain off and the alloy still resists chemicals, not ground thin.

Limestone facades sit gray under a hard crust before the beam. After the pass that crust is gone and the stone is not soaked or ground back.

Redwood siding looks coated and weathered before work starts. Afterward the operator has bare boards that are still sound, without a char streak.

Sandstone walls look crusted and dirty before work starts. Afterward the operator has the same masonry mass, without the dirt taking stone with it.

Stainless steel looks straw-tinted and filmed before work starts. Afterward the operator has a bright chromium face without a burn track.

Heritage architectural work looked stained and tagged on the elevation. Once the head finished, the stone showed through and the old character remained.

Historic masonry looked stained and grimy on the street wall. Once the head finished, the old fabric showed through and stayed itself.

Paint and coating sit on steel and aluminum as a thick film. After the pass that film is off and the metal is ready to inspect or recoat.

Rust sat as a flaky orange crust on damp field plate. Once the head finished, the metal showed through and a fresh coat could go on.