Which Sander Pad Should You Choose?

Which will be the better choice for general sanding — a softer or a harder pad?

I have a Bosch random-orbit sander that is in need of a new pad. Bosch offers hard, soft and extra soft replacement pads. The soft is the original, but would there be an advantage to using the hard pad? I can't find any comparisons or recommendations for these pads anywhere and really don't want all three to do my own testing. It seems fair to say that the hard pad would be equal to my hand sanding block and would be less likely to follow the differences in early/late wood. Any suggestions? - Roger Pozzi

Tim Inman: The texture of the pad will have a direct impact on the quality of the sanding you do. Typically, harder pads will produce a "flatter" surface whereas softer pads will copy an irregular surface or increase the contours where there are hard and soft spots in the wood. Harder pads will "load" worse than softer pads. Softer pads "clean" better. Harder pads will cut off corners and rises. Softer pads will not be good at sanding to reshape a rough surface.

So, which is best? Probably the "medium" one that came with the sander. If you have a specific use for the pad and sander, then go with that. Actually, if you'll just go with a medium pad and keep some harder and softer "sub-base" pads on hand to slip under your clamped-on sandpaper, you'll have the best of all worlds. If you are using sticky discs or hook-and-loop pads, then you must select the firmness, of course.

As a rule, I would pick a medium pad for all-purpose use, and a softer one for fine finish and polish sanding.

Chris Marshall: You're thinking along the same lines as me about this, Roger. The hard pad will be best for smoothing flat surfaces and helping to avoid creating a washboard effect when sanding softwoods with both hard and soft early and late wood grain. If this is what you want your sander to do, I don't think you can go wrong with the hard pad. Of course the softer pads would conform better to contours. I tend to use a spindle sander and disc sander for contours, or sand them entirely by hand, so my R.O. sander is mostly used for flat work. Personally, I'd go with the hard pad.