Wet-Sanding & Polishing
Today I worked on wet-sanding and polishing; starting with the blue areas. The paint straight from the gun leaves a finish that is shiny, but has the texture of an orange peel. The goal of wet sanding is to level off all the peaks of this orange peel texture so that the paint is flat. First 500grit is used, then 800grit, then 1500grit; the panels are kept wet and rinsed frequently to avoid dust build-up that could scratch the paint. It’s critical that the surface is not sanded below the lowest low spot of the orange peel texture, otherwise primer could be exposed and repainting would be required. Luckily the low spots, being untouched by the sanding block, are visible fairly readily as slightly darker spots. After the sanding is completed the paint is flat, but dull looking from the very fine sand scratches. Polishing with rubbing compound and a rotary buffer brings the shine back. The passenger side of the bus is mostly complete; I’ll likely get the driver side complete by the bus’s first long trip, but I’m unsure about the front/back/white areas.