5 orbital sanding mistakes to avoid

Photo By Uneeda Enterprizes

When you want to get the best finish on your project, it comes down to the quality of the sanding. Sanding with a random orbital sander or orbital sander (without random pattern) is not complicated, but there are several things to consider to avoid problems, and get the best possible finish.

1. Avoid pushing down with too much pressure on the sander. We all want to finish sanding faster, and get the best cut from the abrasives, so it can be tempting to press down harder with the sander. Intuitively, it seems like that could make the sanding process go more quickly. However, doing this can cause issues like swirls, cut-through, uneven sanding and other problems, such as excess heat and loading.

The rule of thumb for this is to let gravity, or the weight of the sander, and the abrasives, do the work. Each grit is designed to remove a certain amount of material, so if you need to remove more, use a coarser grit, rather than pressing harder.

2. Avoid sanding too fast, or too slowly. Because sanding is often tedious, many people want to finish sooner by moving the sander very quickly on the workpiece. However, moving the sander at a controlled and even pace across the surface will lead to the best results. It’s a bit of a “Goldilocks” issue – going too fast can lead to poor results, with sections not sanded enough or missed entirely, and going too slowly can lead to over-sanding or cut-through in some areas. But, finding that “just right” speed will mean a nice, even sanding job.

3. Avoid running the sander with RPMs or PSI settings too high or too low. Whether using an electric or pneumatic sander, having the appropriate sander speed (RPM) for your application will be key in achieving a high-quality finish, and avoiding issues like sanding swirls.

On the pneumatic sanders, the main factors contributing to the RPM is having sufficient air pressure and keeping the machine well lubricated. The pneumatics are designed to run optimally with an air pressure of 90 PSI at the sanding machine, and should be oiled daily, if they are used heavily. Pneumatic sanders also have a speed controller that will allow the user to speed up and slow down the speed of the machine. Unless you are using the sander on a special application which requires a slower speed, the sander should always be set at the highest speed to avoid swirls.

4. Avoid starting the sander in the air prior to sanding and stopping it while still on the work surface. Said another way: “Start on, Stop off.” This basic technique is critical in helping to avoid creating swirls at the beginning and ending of the sanding session. The reason for this: making contact with the workpiece when the sander is already moving will make it more difficult to get a good contact with the surface; and at the end, stopping the sander while still on the workpiece means the sander will slow down while still in contact, so it will still be sanding your surface during that lag time.

5. Avoid using the sander on an angle. One of the most common mistakes people make when using a hand sander is using it as if it were an angle grinder. A disc or sheet sander is not an angle grinder and is designed to be used either with a flat sheet/disc directly on the backup pad (for flat surfaces), with a foam interface pad or hook and loop pad saver and conventional abrasives (application varies), or with foam abrasive for finishing on flat, curved or complex profiles.

When using a sander on an angle, rather you’re creating an area that is sanded more than another area, leading to an uneven surface, and therefore an uneven finish.

Source: Uneeda Enterprizes. For information call 877-863-3321 or visit sandpaper.com.


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