Raising the Grain Overview
Back in the day when I was turning so many production bowls, I was always looking for ways to help me achieve a better finish. One of the first things I did was to mandate that the minimum level of finish sanding for my production bowls would be 600-grit. Of course, my artistic projects are always sanded to a much higher level, up to 12000-grit (twelve thousand), depending on the material and the clients’ desires.
Most of the production turners I knew back then only sanded to 320-grit or perhaps 400-grit and they believed there was no benefit to sanding any higher on a utility bowl. I agreed to disagree and set a rule in my studio that 600-grit was the minimum level of sanding for any of my production bowls. This rule endures to this day. I believe a high quality finish starts with the bare wood surface. The tactile quality between a surface sanded to 420-grit and one sanded to 600-grit, is easily discernable as you run your hand over the project. Whilst a bare wood surface sanded to 600-grit is pleasing to the touch, it needs one last step before you begin to apply the finish – you need to raise the grain.
Benefits of Raising the Grain
Raising the grain is a simple process, but a very important one that you should consider in your studio before finishing some of your projects. You can raise the grain with a damp paper towel (kitchen paper) moistened with distilled water, or you can use a spray mister bottle filled with distilled water. Do not use regular tap water as many of the water supplies contain trace minerals that may discolour the wood, especially if you are using water from your own well. When you apply a damp paper towel to a bare wood surface that’s been sanded to 600-grit (or less if you prefer), the tiny fibers in the wood swell up and stand proud of the surface slightly.
When you run your hand back over the dried surface of the wood after raising the grain, you can easily feel these tiny fibers. These tiny fibers need to be sanded again before you finish the project because they can sometimes raise during finishing, depending on the type of finish you use. By addressing the potential for grain raising before you apply a finish to your project, you virtually eliminate any chance of the grain raising during your finishing protocol. It’s an extra step in the finishing process, but a very important one if you want to achieve a better quality finish.
How to Raise the Grain
Here’s the protocol I use for raising the grain on production bowls, artistic bowls, platters and hollow forms in my studio:
Sand the bare surface of the timber to 600-grit minimum. Blow away any residual dust in the pores of the timber using a blast or two from a high-pressure air hose. I typically set my compressor for 90psi and use a pistol grip type of air gun, or a small hand held nozzle.
I usually set my air compressor to
90 psi for removing residual sanding dust
Once the surface is free of dust, moisten a paper towel with distilled water and lightly wipe the entire surface of the project. Note: The paper towel should be wet, but not dripping wet. We do not want to flood the surface of the wood, only slightly dampen it. You may have to re-moisten your paper towel several times on a large project.
When raising the grain,
use distilled water if possible
The moistened surface of the timber should dry fairly quickly, since you’re not saturating it with the water. If I’m in a rush, I will usually spray the surface with compressed air to speed the drying.
On larger projects, a spray
bottle with a fine mister is handy
Once the surface of the timber is dry, run your bare hand over it and pay close attention to the amount of grain that has been raised. Some timbers will produce a lot of raised fibers; others will only have a minimal amount. By checking each species after you’ve raised the grain, you will be gaining important information about the local timbers in your area. Those that produce a lot of raised grain may benefit from a second application of the distilled water on the surface. Most timbers only need the grain raised once prior to finishing, a scant few benefit from two applications.
After the surface is thoroughly dry, resand the entire surface using the last grit you used on your project. For example, in my studio on a production bowl, the last abrasive grit I use is 600-grit. After I raise the grain and the bowl is dry, I resand with 600-girt. If you prefer to use a courser grade abrasive as your final grit, use that grit of abrasive instead.
Pistol grip air guns are great for removing
dust from the surfaces of woodturnings
After the entire project has been resanded after raising the grain, remove any dust with a few shots of compressed air. Observe the surface of the timber under a bright light (outside in sunlight is ideal for close inspection) and resand any areas if necessary, to insure an evenly sanded surface. Remove any residual dust with compressed air and you’re ready to begin applying the finish to your project.
If you’ve never tried this technique on your projects, I encourage you to do so. The quality of the finish on your project can dramatically improve with proper sanding and a few minutes spent raising the grain before finishing. I know it’s an extra step in a finishing process that’s already too long for many people, but if you want to improve the quality of your finished surfaces, you have to pay the piper. There are no shortcuts to a perfect finish! I know this technique will help to improve the quality of your finished surfaces, give it a try and see for yourself.
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.