Chattering is a phenomenon that is caused by unwanted vibrations when working a piece of material, particularly if that material is soft.
Chattering is most likely to occur if using an incorrect technique when cross filing or lathe filing.
It is far less likely to happen during draw filing. Not only is it more difficult to draw file with too much pressure if you are using the wrong technique, but the workpiece is also less likely to vibrate due to the fact you are filing lengthways, as the vice will be providing more support.
These vibrations cause shock waves in the workpiece and distort the surface, leaving a radial pattern that is difficult or impossible to erase.
How can you avoid chattering?
Chattering rarely occurs when filing, especially when working with wood or plastic, but there are three main things to bear in mind that will help you to avoid it:
1 – Two hands
Always use the file with two hands so that you can apply consistent, controlled, light pressure. This will stop the file from skipping or jumping as you use it.
2 – Light pressure
Don’t press too hard when filing. Aside from potentially damaging your tool, applying too much weight to the file can cause the teeth to catch in the workpiece, which will result in a jerky filing motion.
3 – Keep your file clean
Make sure your file is clean and the teeth are not clogged. Clogged teeth will skip across the material, and the clean teeth behind will then bite into it causing a jerking sensation. If multiple teeth are clogged, chattering is more likely.
If you are 100% confident that you are using your file correctly and you are still suffering from chattering, it is possible that the material you are working on is not suitable for being filed, and you should contact your supplier.
How do you know when chattering is happening?
If you can hear an unpleasant screeching noise when filing, or if it feels like your file is jerking across your workpiece, you should stop and check to make sure you are not causing damage.