Using Interface Pads
When Power Sanding

Interface pads are available
in various sizes and densities

Power Sanding Overview: Let's talk a little bit about sanding. I'm a big fan of power-sanding in my studio. I prefer pneumatic sanders for production work, as the electrics always tended to burn up on me. I went through five electric drills one summer before I switched to pneumatics. While this has made my abrasive work easier and more productive, all the tool does is turn the mandrel pad. The real finesse in sanding comes into play when the abrasive meets the surface of the wood.

You have to use good quality abrasives to get the best sanding performance and the density of your sanding pad (or disk holder) has to be optimized for the type of timber you're sanding. This means that you need at a minimum, three different densities on your sanding mandrels, soft, medium and firm. Herein lies the rub…

Many manufacturers do not offer variable densities in their sanding mandrels. This can create problems when sanding, as the density of the foam sanding mandrel has a significant impact on the quality of your ultimate sanded surface.

Using interface pads on your air sanders will greatly extend the sanding pad's life

Power Sanding: Problems With Some Timbers

Some timbers like Mulberry have very soft spring wood (the faster growing section of the tree that grows in the early spring, just after the tree leafs out) and very hard summer wood (the slower growing and denser late wood that grows slowly in the summer). If you sand these timbers with a soft faced sanding mandrel, you will get an undulation in the surface of the wood.

This is easily felt as you run your hand over the surface of the wood and you feel the late wood ridges standing proud of the early wood. The surface feels like the beach during low tide, where the beach sand is rippled from the wave action. To prevent this uneven sanding, you can use a firm faced mandrel, which has enough density to sand the surface evenly.

Another problem can present itself if you use a very dense and hard faced sanding mandrel on projects with a significant amount of contours or surface embellishments like beads, coves or other fine detail. The harder pad can flatten some areas and destroy fine detail. What's needed here is a soft pad, which can easily conform to tight curves and contours in fine detail areas much easier than a firm pad.

Power Sanding: Problem Solved

Some of the interface pad
sizes that are available for
power sanders

Even if you could find a manufacturer that offered sanding mandrels in multiple densities, it would be expensive to keep numerous units on hand for sanding. Several years ago a few manufacturers began offering interface or backing pads for use in power sanding.

These interface pads are simply small rounds of Velcro faced foam in varying density, that attach to standard Velcro sanding mandrels. The abrasive is then attached to the face of the interface pad. This setup offers several distinct advantages.

You can have one sanding mandrel in each size you need (for example, 1", 1.5", 2.0", 2.5", 3.0" etc.) and by using two different interface pads (soft, and firm) and using the mandrels pad as the medium density surface, effectively triple your mandrel inventory.

Each mandrel can be rapidly switched to the density needed in about two seconds (rip off current pad, install new one and attach Velcro backed abrasive). Another benefit is that when you eventually wear out the Velcro face of the interface pad, the replacement pads are very inexpensive, whereas the mandrels themselves are none too cheap.

Velcro-faced power
sanding mandrels

Power Sanding: Advanced Interface Pads

Interface pads are also available for wave edge abrasives

Some interface pads are also available in a "doughnut" configuration, with a hole in the center of the pad. This helps the pad to follow the outside contours of a rounded form better than using a traditional flat pad.

These doughnut pads are available in several sizes as well. I have been using interface pads for many years in the studio. They work extremely well and will save you money in the long run by protecting the Velcro face on your sanding mandrels/disk holders.

The next time you get a little heavy handed when sanding and you melt off the Velcro holders on your sanding mandrel, you'll know why I love interface pads so much. Get yourself a few of these interface pads and you'll be in sanding nirvana, well close to it anyway!

Interface pads are available from most woodturning stockists. Please note, they may be listed in their catalogs as backing pads, interface pads or under a similar name.

3" velcro-faced power sanding mandrel with interface pad attached

Safety Note: Always follow all manufacturers safety instructions before working with your lathe, or any of the tools or products you may use. If you are unsure about any operation, obtain competent professional instruction before proceeding. Use and wear all necessary safety devices during turning and observe safe woodturning practices to prevent accident or injury.

Steven D. Russell is a professional studio woodturner, teacher and writer. He has written numerous articles for international woodturning magazines, which have been published in more than 78 countries around the world. Steve has demonstrated in numerous cities across the United States. His studio, Eurowood Werks, specializes in bowls, platters and hollow forms with unique visual and tactile treatments.

Steve is also the current and founding President of the Lone Star Woodturners Association, Inc., an AAW member chapter. The LSWA is a 501(c)3 non-profit educational organization dedicated to teaching and demonstrating the art and craft of woodturning.

Steve is also a featured writer for the Guild of Master Craftsman's "Woodturning" magazine, published in London England. Woodturning magazine is the world's leading magazine for woodturners. Look for his articles covering technical topics, or project based articles in an upcoming issue.