Re-sawing lumber is the process of cutting a board into two or more thinner boards. This is usually accomplished using a bandsaw, and is only limited by the maximum cutting height of the saw itself.
Safety is very important when resawing a board. Attempting to resaw a board that is too wide or too dense will put strain on the saw and blade. This can result in a dangerous situation.
There are several aftermarket fences and tools that are specifically designed for re-sawing. Research what is available for your saw, especially if it will make the job safer.
One of the most important considerations when resawing is the blade selection. Generally, the wider the blade, the better. In most applications, you can use a hook or skip tooth style blade. Choose a blade with 3 to 6 TPI (teeth per inch). This will provide a rougher cut, but offer a larger gullet which will remove sawdust and prevent heat from building up and binding. This improves horsepower and results in faster cuts. After a resaw, the board is usually planed smooth, so blades with fewer teeth are okay.
To resaw lumber into thinner boards:
The bandsaw must be adjusted correctly. Refer to your vendor manual as necessary.
The table must be square to the blade. Refer to your vendor manual as necessary.
Use the widest blade available, with 3 to 6 TPI. Make sure the blade is in good condition.
Use a fence to guide your work.
Draw a reference line down the edge of the board.
Support the ends of board as necessary, don't let extra weight hang off the ends of the table.