I know that it's a pretty basic and straightforward topic. But still there are some tips that are worth sharing when working with plywood. Being a little more informed about the different variety available as well as techniques for handling plywood helps in making better building decisions.
How to cut a large plywood sheet
First thing to keep in mind, and you know this but it still worth repeating, plywood is heavy. A full board is both heavy and cumbersome to carry. So take care when moving the sheets. There are some simple appliances you can use to assist you In moving sheet goods around your workshop. The most common and easy to find it is a trolley on wheels or rollers. You can probably find that out your closest home depot.
The large size and the weight of plywood also makes it difficult to cut a full sheet directly on the table saw. The alternative is to cut it into small size using a circular saw. The most convenient way to do is is to procure a 1 1/2 inch thick installation About the same size as yours sheet and play it on the floor. The installation sheet cost about 20$.
The purpose is to put the foam sheet directly on the floor so can so you can lay the board directly on it and start cutting to size using the circular saw. You are mainly cutting to make smaller and more manageable pieces that will receive their final and accurate cuts on the table saw.
I want to mention here that there is every possibility of getting clean and accurate cuts with your circular saw in the first place as well. You can do this by using a good circular saw and a reliable guide to make the cuts. There are some complete systems available that are a combination of a circular saw that fits on a custom guide enables you to make a very clean and very straight cuts. However, if you don't want to invest in a complete system you can purchase a generic cutting guide or fashion one yourself in your workshop. They are pretty basic and very easy to make.
And just so that you know, the installation form sheet is going to last you for many cuts and many boards before you need to replace it for another $20. Set the blade of the circular saw to go slightly into the foam.
Remember to put the board good side down because the circular saw blade rotates upwards so you are likely to get some tear out in the side facing up. A way to avoid that is to use good sharp blade, like the carbide tipped ones, or even better use the special blades that come for cutting plywood. They are a useful investment if you cut plywood a lot. The way they word is by having a large number of teeth and taking very small bites. You can find these specialised saw blades for your table saw as well.
Cutting a board directly on table saw
If you are going to cut large sizes of plywood on a table saw, the first thing you are going to set up is an out-feed support. There are many kinds but one with the rollers is ideal. Outfeed helps support the sheet once it comes off the table and keeps it moving along smoothly. Remember to align the out-feed absolutely in line with the blade and very slightly lower than the surface of the table. If it isn’t straight it will tend to skew the boards in its direction making it difficult for you to make a straight cut.
Since the plywood board is large and heavy it is not recommended that you stand directly behind it while running it through the blade. In order to get a straight cut, the board needs to be pressed firmly against the fence. It’s size and weight will want to make it to move away from it.
You will be in a better position if you stand on the side rather than directly behind it. In this way you can grip the side of the board as well as the backend and exert equal pressure forward and sideways to keep it pressed firmly against the fence while making the cut. Keep an eye out on the edge of the fence so that you know when the board begins to tilt.
What side should be up
You know that the two faces of a plywood board are usually different. One is the good side that is meant to be seen and the other is meant to be on the inside of the wood project. You should also know that when cutting with a saw, a tear out can occur on the side that the blades come out off.
This is minimised by using a sharp blade. The more expensive and advanced carbide tipped blades reduce the occurrence of a tear out even further.
In a table saw the teeth rotate towards you. This makes the saw is safer to use by reducing the chances of a kickback when you push the wood into the high spinning blade. It also prevents splinters from coming your way.
The blades enter from the top of the board and exit from the bottom. Therefore place the board with the good side up while cutting on the table saw. The opposite applies when cutting with a circular saw.
Don't be afraid of wastage.
Sheet goods are expensive and nobody likes to waste it. But it happens so many times that if you try cutting a large board directly to size something goes wrong that throws the measurements off. It could make more sense to make a larger rough cut and then find tune it according to your final measurements. Some wastage will occur. But wastage is inevitable when you are working with wood. And you do get more accurate cost cuts while awarding the frustration of having to fix your mistakes.
Another instance of waste can occur when you are trying to pick a universal look for the project you are building. Let's say you are building a cabinet and you need to take out a few panels from a plywood board. Now economic make sense will dictate that you mark measure and cut in a manner that allows you to take out the maximum material from the board.
But this is not the most aesthetic way to do things. The reason is the wood grain pattern on the front face of the plywood. Every plywood board that comes with a veneer face will have the wood grain according to which wood it has been cut from. This grain pattern will not likely be the same throughout the length of the board. This again has to do with the way the way new sheet was cut from the original lumber.
So if you don't plan it, the different panels cut can end up looking different to each other which in turn will look odd when you put the project together.
In order to avoid this you need to cut out panels from the same looking parts of the board. That calls for wastage but is necessary in maintaining is the aesthetics of your project.
So those are some useful tips for cutting plywood, do share your views in the comment section. As always we look forward to your input .