Only two sheet goods will be discussed; plywood and medium density fiberboard (MDF)
What are sheet goods?
They are a collection of a variety of wood products (manufactured) that are specifically used where standard dimension lumber would be hard to use. Imagine you are building cabinets. While you might be tempted to use the dimensional lumber for the whole project, plywood would be an obviously better choice for various parts like the shelves, sides, top and bottom. Why? For starters, the plywood would be cheaper and even stronger!
As is with any other product, sheet goods are not without cons. The major one though, has to do with the veneer on the face of various sheet goods including plywood and MDF; it is extremely thin. This poses as a problem especially if sanding is not restricted to just the superficial board’s face and more is required.
In the construction industry, plywood is one of the most widely used wood product but when it comes to woodworking, you can only use it for projects such as making cabinets. Plywood is made up of softwood laid down in thin layers where the grain of one layer is perpendicularly placed to the previous layer. The thickness of the plywood is dependent on the number of softwood layers used. When you use thick plywood, you can expect the finished product to be very strong and can be used in a variety of applications.
If you have some little experience in woodworking, you would know that a 2 by 4 dimensional lumber piece doesn’t exactly measure that The same applies to identifying various plywood sizes and I wouldn’t blame you if you got confused. Take for instance a 4 by 8 plywood sheet. While it should measure that in ft., the thickness is the one that matters. Even though in some instances thickness doesn’t matter, it is crucial when it comes to inserting a plywood piece in to a dado. If you don’t want the joint to be sloppy, before cutting the dado you should find out the plywood’s exact thickness.
Grading of plywood.
When it comes to plywood grading, a lettering system is used. Grading is dependent on the wood quality, wood grade, and available blemishes and sanding. Before making a purchase, ensure that you know the difference between COX plywood and A-C plywood as the terms can be pretty confusing. It doesn’t and there; bonding type and the final intended plywood application is also considered in the grading.
Treatment of plywood edges.
Depending on the intended use and price, the faces of a plywood sheet could either come sanded or otherwise. More often than not, the plywood edges come uncovered and if you look closely you can see the layers of softwood used in manufacturing. Other than being unsightly, this uncovered edges pose the risk of splintering or water damage to the plywood which is why you should use the techniques available to treat the plywood edges.
MEDIUM DENSITY FIBERBOARD (MDF).
Mills usually have a lot of leftover milling products especially from SPF lumber milling. Instead of letting it go to waste, mills use the ground off cutoffs and the extra left over stock pieces to make a product that is viable; MDF. Medium density fiberboard is a sheet made of pressed small wood pieces glued together. Thin veneer is applied on the faces of the sheet and sometimes the edges to make it finer.
You can use MDF to make storage units, cabinets and wall panels.
Particle boards are made of saw dust, wood shavings and wood chips that are mixed with resin. You could use particle boards as an alternative to plywood or MDF is you are on a budget. Applications of particle boards in wood working. In the production of mass furniture, particle boards are a widely used item. Why?
It is relatively cheap
It is easy to work with
When thin veneer is applied on it, it attains a rich hardwood look. It is for this reasons that it is also used in wood working projects.