Lathe filing is a technique used for shaping, finishing and polishing cylindrical objects such as table or chair legs.
A lathe is a machine for shaping that spins a piece of material around to allow consistent cutting around its circumference.
This process allows for more precision and finer cutting than the use of a wood-turning chisel, which cuts more deeply and is more effective as a shaping tool.
Special files, called long angle lathe files, are designed for use in this process, although it is possible to use mill files, as both types of file are flat and single cut.
Attach your workpiece securely to the lathe and switch it on. The material should be rotating towards you.
If the lathe isn’t spinning quickly enough then you may end up with an uneven shape (referred to as ‘out of round’).
If it’s too quick then the file’s teeth could skate over the workpiece, which will damage it and potentially break your file.
Setting the lathe to spin around 600 rpm should be about right.
Step 2 – Grip file securely with both hands
Hold the handle of the file with your dominant hand, with your thumb on top of the handle, aimed towards the point. Hold the point with your non-dominant hand between your thumb and forefinger.
Step 3 – Check your positioning
Keep an eye on whichever of your elbows is closest to the lathe chuck (the part that grips the material and does the actual spinning).
If possible, it may be an idea to file left handed so that you can keep your elbows well out of the way.
Banging your elbow into it could be very painful and it could also cause you to make a huge mistake with your filing that could ruin your work!
Step 4 – Lathe filing
Using short, forward strokes, file your workpiece until it has the smooth finish you’re looking for. Just as you did with cross filing, slide the file slightly to the right as you move it forward, while making sure the point of the file is angled directly away from you at all times.
Pushing too hard in lathe filing is likely to result in broken file teeth and loss of control of your file, which could result in damage to your workpiece or you yourself! When lathe filing, you can apply slightly less pressure than you would when draw filing or cross filing.