What is Plywood?
Plywood is an engineered wood product consisting of three to seven layers of thin sheets of wood veneer that are then glued together. Each veneer is laid with its grain at a right angle to the last (or tighter angles such as 45 degrees in some plywood). This is done to create a product with high dimensional stability that resists splitting and warping.
What are the Advantages of Plywood over Solid Stock?
Plywood’s main advantage over solid stock is its high strength and stability. Its availability in a variety of thicknesses and sizes often makes plywood a more convenient choice as well. Plywood comes in a variety of thicknesses (typically 1/8″, 1/4″, 3/8″, 1/2″, and 3/4″), which can eliminate the need to plane your own boards. It also comes in large sheets (typically 4’x8’), which can eliminate the need for edge-joining.
What are the Disadvantages of Plywood?
The face veneers of plywood are very thin—1/30 of an inch, on average. This can make plywood hard to cut without splintering, and doesn’t leave much after sanding. Plywood is heavier than solid stock and more susceptible to water damage, which could be problematic for some applications. The edges must be finished specially, usually with edge banding, to conceal the layers.
How Does the Cost of Hardwood Plywood Compare to Boards?
By the board foot, hardwood plywood is comparable in price to solid hardwood.
What are Good Uses for Hardwood Plywood?
Hardwood plywood is well suited for a variety of common uses. It is often used in cabinetry and furniture making. Many musical instruments are made from hardwood plywood, including pianos and string instruments.
What do the Different Plywood Grades Mean?
Plywood is graded A-D (best to worst) for its front face and 1-4 (best to worst) for its back. A1, A2, B1, and B2 are acceptable for applications where both sides will be seen, while A4 or B4 would be fine for projects where the back will not show.
Guide to Plywood Core Options
When it comes to plywood, is it what’s on the inside that counts? All hardwood plywood has a face and back veneer of hardwood, but the core can vary. Here’s what you need to know about the different plywood cores available.
Veneer Core Plywood
The most common type of plywood core is made up of layers of veneer–typically fir in the west, poplar in the east, and aspen in the northeast. Of the three most common types of plywood core, veneer core is the lightest (approximately 70 pounds per 4×8 panel) and has the best strength, stability, and screw-holding properties. It is also the most expensive and the least uniform, since the layers of wood veneer have natural voids.
Particleboard Core Plywood (PBC)
The cheapest core option is particleboard, which consists of refined wood particles of varying sizes bonded with urea formaldehyde. It is the weakest plywood core option (although still denser than solid wood) and does not hold screws as well. PBC is also very heavy (a 4×8 panel weights approximately 100 pounds) and swells up when exposed to moisture. It does offer a more uniform texture than veneer core plywood, creating a smooth void-free surface for veneer.
Medium-Density Fiberboard Plywood Core (MDF)
MDF is an engineered wood product similar to particleboard in which the refined wood particles are of a smaller, uniformly sawdust-like consistency. It’s a step up from PBC and down from veneer core in terms of strength, stability, and screw holding ability, and is priced between them. Like particle board, MDF is very heavy, will soak up water, and offers a void-free surface for veneer application. Because of its very uniform consistency, cut edges appear smooth and are easy to finish with paint.
Combination Core Plywood
Combination core is a less common and more expensive option used with some expensive hardwood veneers. A combination core uses a layer of MDF or particleboard directly under the face and back veneers and veneer layers in the middle to get the best of both worlds—a smooth, uniform surface for face veneer application combined with the strength and stability of a veneer core.