A drum sander is a powerful addition to the workshop that can present the new user with a steep learning curve. It is capable of extremely precise thicknessing on even the most difficult timbers – but only when operated correctly. Here are a few of the most important tips to help you get the best out of your drum sander when thickness sanding.
Clean, Fresh Abrasive
Ensure your abrasive is clean and clear of any gum residue. Clogged abrasive doesn’t cut well, and in extreme cases, it can even leave dark burn marks on your workpiece. Resinous timbers are the main culprits, so if you are working with gummy softwoods or tropical hardwoods with high resin content, check your abrasive often.
Dust Extraction
A drum sander absolutely must be used with appropriate extraction! It creates a huge amount of very fine and very hazardous dust that can cause you serious health issues down the line. Un-extracted dust will also sit on the workpiece, reducing the efficiency of the abrasive and causing burning and clogging.
Correct Feed Speed
Selecting the optimum feed rate for your workpiece is crucial. Light passes in non-resinous timber can usually be made at full speed. At the other end of the scale, heavier sanding in ‘sticky’ timbers should be made at slower speeds. It will vary depending on the species and the condition of the abrasive. Burn marks (and a smoky smell!) usually indicate that the feed rate is too fast. Spending a whole afternoon doing a single pass usually indicates that the feed rate is too slow!
Correct Depth of Cut
The drum should be lowered very gradually into the workpiece. Almost every poor outcome when thickness sanding is a result of setting the machine to cut too deeply. It is helpful to think in terms of ‘fractions of a turn’ of the depth handwheel. For example an eighth of a turn might be a light cut, while a quarter of a turn might be too heavy and will need to be backed off. A heavier cut requires a slower feed speed, and vice versa. Balancing these variables is part of the art of thickness sanding! Does your workpiece require lots of fast, light passes? Or just a few heavy, slow ones? Practice and experimentation is the key to mastery.
Multiple passes per height
You will find that if you pass the workpiece through a second time without changing the cut height, the abrasive continues to engage the surface. Often a good routine is to reduce the cut height every two, or even three, passes. This increases the chance of accurate thickness along the length of the workpiece.
Listen and Measure
You should still be able to hear your machine through your earmuffs or earplugs; pay attention to what you hear. If you have set the cut depth too aggressively, you will hear it! Using calipers after every pass, at multiple points along the workpiece, is the best way to ensure maximum accuracy. Constant listening and measuring will help you master your drum sanding.