Wood Blasting

Overview

Blasting on wood surfaces is used to remove old paint/varnish layers, reveal the original texture and appearance in restoration work, or prepare the surface before repainting. Because wood is porous and relatively soft, low pressure and gentle abrasives such as blasting soda or glass beads are preferred; hard/aggressive abrasives can damage the wood fiber and leave an undesirable rough surface.

Pressure setting and nozzle distance are the two most critical parameters that directly determine the blasting outcome on wood: at low pressure the surface is not cleaned sufficiently, while at high pressure the difference in density between early and late wood (between annual rings) can leave a wavy, "toweled" texture on the surface — in some restoration projects this effect is deliberately chosen for a decorative "rustic" look, but otherwise the pressure should be adjusted through gradual testing. Hardwood species (such as oak and beech) tolerate higher pressure than softwood species (such as pine and spruce); therefore recommending a standard pressure value before the wood type is clarified does not yield accurate results. In indoor restoration work, dust control (vacuum blasting or wet systems) is important both for worker health and to prevent secondary contamination of the artifact/structure.