There is often a perception in the auto body industry that the sander of choice is dependent upon what part of the shop it is used in. In some cases this is true, but there is much more to consider. In the past, tool companies have touted the orbit of a dual action sander by “coarse throw” and “fine throw.” This has given the industry a false sense of what the orbit does to the performance of an abrasive disc.
|3M™ Cubitron™ II Clean Sanding Hookit™ Disc|
The assumption has been that coarse throw or large orbit tools are used with coarse grade abrasives, while fine throw or small orbit tools are used with fine grade abrasives. With further investigation and testing, this has shown to be a false way to look at sanders and applications.
The orbit or “throw” of the tool is the amount of offset the counterweight moves when a sander is in motion. If a large orbit sander is used, it will move the abrasive in a larger motion allowing the abrasive to cut more. If a small orbit tool is being used, the abrasive will move in a small motion. The amount of movement will determine the cut performance of the abrasive. The biggest factor impacted by the orbit of the sander is the amount of cut that is transferred to the abrasive. In fact, the cut from a large orbit tool (5/16”) is as much as two times when comparing to a small orbit tool (3/32”).
When you increase cut, you increase refinement speeds as well. For example, when sanding to refine P1500 grit scratches with P3000, a 5/16” orbit tool will remove the P1500 scratch twice as fast. This helps get the vehicle out the door quickly. Cut increases significantly help both the body and paint shop side of the business.
The fear that many technicians have when using larger orbit tools is the impact it will have on the scratch finish. This is due to the old terminology of categorizing tools as “coarse or fine.” The orbit of a tool has shown very little effect on the scratch finish of the abrasive. It does not matter if you are using a P800 disc with a 3/32” orbit tool or a 5/16” orbit tool. The finish is still a P800 scratch. The bigger difference will be the cut performance of the abrasive disc. The production increase of using larger orbit tools far outweighs the small differences in scratch.
Small orbit tools originally started in the wood-working business and made their way into the auto body industry. A 3/32” orbit tool is very comfortable with no vibration, but they also have very low cut and generally tend to decrease the performance of abrasive discs. Since the abrasive has very little movement, it will also load and clog up since the dust will be trapped underneath. Large orbit tools do a better job at kicking out the dust from underneath the abrasive, limiting the amount clogging on the disc.