Plywood is available in a number of grades. Be sure to choose the right one for the job in hand. Some have one finished side, others have two, and some have none, if the plywood is hidden.
For rough work, shuttering plywood is adequate and cheap. For external use always choose weather-proof plywood, or marine ply. If in doubt, consult your local supplier.
Store plywood flat to prevent warping. if you must store it on its edge, rest it on wooden blocks so that the bottom edge won't absorb moisture.
To keep all edges from absorbing moisture, rub them with a stub of candle wax.
When cutting plywood with a hand-saw, place the finished side face up so that any splintering will occur on the rough underside. If you're using a circular saw or jigsaw, place the finished side face down.
To prevent splintering, cover the cutting line with masking tape, then mark the line on the tape.
Or score the cutting line with a craft knife-just deep enough to penetrate the top veneer. Then make the cut; any splinters will break off cleanly at the scored line.
Finish plywood edges with veneer tape. Or use adhesive plastic.
Plywood occasionally blisters as the top veneer peels away from the core layer. To fix this, slit the blister with a single-edge razor blade and squirt a little glue inside. Spread the glue under the blister with a toothpick. Then cover the area with wax paper and weight it down overnight with large books.
Don't toss out a sheet of plywood just because it's warped. First try moistening the concave side, then lay the sheet flat with weights on top. If that doesn't work, save it to use in small pieces.
