Some simple rules will smooth things - Rule 4: Open-coat abrasives avoid clogging

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Rule 4: Open-coat abrasives avoid clogging
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Rule 4: Open-coat abrasives avoid clogging
Clogging of abrasives is a woodworking issue that slows down productivity. Clogging begins with some abrasives because a great deal of static builds up during the sanding process.

The solution to this annoyance relies on anti-static strategies, which includes what is called an “open coat” process. By maintaining space between grit clusters, resins and sanding dust naturally fall away rather than adhere to the abrasive. This allows a shop’s dust collection system to easily remove particles from the environment. Also, a stearate, which acts like a dry lubricant, is applied to some abrasives to discourage clogging.

The use of closed-coat abrasives is recommended on hardwoods such as cherry and oak, while open-coat abrasives should be used on softwoods such as pine, balsa and any of the firs. The use of closed-coat abrasives on hardwoods ensures you will get a good abrasive life, rate of cut and the best finish possible. It may even allow you to reduce the number of grits in your sanding sequence. The use of open-coat abrasives on softer woods will allow you to sand for longer periods of time per belt as the spacing of the grain will help alleviate the loading or clogging common in softwood sanding. Some of the open-coat materials in cloth also are washable, another way to get some extra abrasive life when sanding problematic soft woods.

Rule 5: Remove PSA discs from sander while hot
Pressure Sensitive Adhesive (PSA) discs must be removed from a sander’s backup plate, or pad, before they cool. Most PSA material is heat sensitive and the adhesive properties are activated while in use. When you activate the properties, then allow the disc and adhesive to cool while on the backup pad or plate, the two bond together. Now removal consumes more time and may damage equipment in the process.

On the larger diameter PSA discs (12" or larger), putting a thin film of paraffin on the metal plate for the stationary disc sanders will help make for easier removal of the disc when change-out is necessary.

A better solution is a hook-and-loop system, which works like Velcro. This removes the temperature control problem and allows for speedy, efficient change-out of discs.