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A dual action (DA) sander is a versatile tool that is generally overlooked in most applications and operations.

Sometimes, there is a misconception that the operator does not have to be trained since it is a relatively simple tool to operate. On the contrary, DA sanding should be considered complex. It is a manual operation where the operator has to rely on his or her ability to remove surface defects and produce a consistent finish at high production line rates. As with any sanding or finishing operation, all aspects of the application are important. The DA sander itself, the air supply, air hose, back-up pad and the abrasive play important roles. Any one of these alone can cause a defect to the workpiece.

The following are suggestions and recommendations which will assist in eliminating common problems.

START-UP CHECKLIST

1. Examine the sander prior to attaching to the airline

The DA sander should not be operated if any parts are missing from it, i.e., muffler assembly, which will cause the sander to operate improperly.

2. Examine the back-up pad for damage

If the foam is separating from the pad face, is torn or adhesive remains on the vinyl face, the pad should be replaced immediately. All of these issues can and will cause surface defects because the abrasive disc is unable to sand flat and evenly on the workpiece surface.

3. Check air pressure at the regulator/filterT

he sander will not operate efficiently unless the air pressure at the tool is 90 psi while under load.

Never operate the sander at higher than the manufacturer-recommended PSI because it will cause premature tool wear.

4. Examine the air hose

If there are tears or if the connections are loose, the hose should be replaced. When damaged or broken, a serious injury could result.

Hose length should be as short as possible and not exceed 20 ft. in length. For every additional 20 ft. of hose length, the air pressure drops by approximately 50 percent.

Do not use a coupler to increase hose length; each coupler is equal to an additional 15 in. of hose length, thereby reducing pressure.

5. When the sander is connected to the air line, check for leaks in the hose and coupler/plug.

Air supply is critical to the performance of the sander. Without proper air pressure and volume (SCFM), the sander will create surface defects.

6. Make sure the sander has the proper orbit for the operation/process being conducted.

There are two orbits commonly used: 3/16 in. for general sanding and 3/32 in. for producing fine finishes. The orbit and rpms can be found on either the sander’s lever or housing.