Finishing surfaces, constructing parts and applying veneers
A thin sheet peeled in a thin layer from a log is called veneer (thicker than 0.3 mm). Plywood is made by gluing veneers on top of one another with their grains at right angles; glued plywood has an odd number of veneers, from 3 to 15. Plywood warps less than boards, cracks less, bends easily and is convenient to carry. Finishing is the last stage of work: the item is made attractive, its moisture resistance is increased and it is protected from insects. Kinds: sanding, patterning, burning, staining, varnishing and painting. Varnishing is applying several coats of varnish; spirit, oil and nitro varnishes are used, applied with a brush or a pad. Oil paint gives a moisture-resistant layer but dries slowly (about 24 hours). Varnish and paint are poisonous and flammable: work with them only under adult supervision, in a ventilated room, with gloves and work clothes, and never leave oily rags in the workshop, because they can cause fires.
Plywood model: glue 3 card (or paper) strips with their lines (grains) at right angles. Compare with a single strip: which resists bending better? Wash hands after working with glue.