I figured that this was a good article to post for you all....

This article covers the following Porter-Cable tools:

The 7335 5" & 7336 6" Random Orbit Sanders and the 7424 Car Polisher.

These tools are essentially identical in that they all use the same body. The difference lies in how these tools are outfitted. Therefore, if you own any one of the above models you have the capability to convert it into either a 5" or 6" sander/polisher. But before you can proceed you must understand that depending on the pad diameter one of two counterweights is used.

The counterweight is a half-moon shaped piece of metal attached to the rotating shaft of the tool. This smooths out the random orbit action by providing a counter balance to the elliptical orbit of the rotating backing pad. If you change the pad size you must also change the counterweight or suffer unnecessary vibration and possible damage to the tool.

There are two different counter-weights which are clearly marked to indicate use with either the 5" or 6" backing pad. Therefore if you decide to outfit the 7335 5" Sander with a 6" backing pad for sanding or polishing you must switch to the counterweight used with 6" backing pads. The same goes for the 7336 6" Sander. If you decide to outfit it for 5" sanding or polishing you must switch to the counterweight used with 5" backing pads.

Porter-Cable 7424 CAR POLISHER The only exception is when using the 54745 6" Foam Polishing Pad. Due to its light weight and the small-diameter backing pad used (included with pad), it can be used with the 5" or 6" pad counterweight. Porter-Cable outfits the 7424 Car Polisher with the 5" pad counterweight.

 

Does that mean the counter weight on the 7424 should be changed to the 6" weight to use the double sided durafoam pads? I'm since the box say its a 6" polisher.

 

on the edge system there is no need to get the 6 inch counterweight, per the manufacturer.

 

Thanks Phil.