Published: Nov 27, 2009
Review: Forrest Saw Blade Dampener & Stiffener
Not really needed?
$22.55 from Amazon.com
(click the small images below to see larger versions)
I love Forrest blades. They're almost legendary and for good reason. The cut is superb and they just ooze quality. I use the Woodworker II and Chopmaster.
Forrest recommends using a stiffener on all their blades. It's supposed to add support to the blade to reduce vibration from the cutting, as well as dampen out vibrations from the motor/belt and keep them from being transmitted to the edge. All this is supposed to improve the quality of the cut and reduce noise.
My first thought was "Improve the cut? Really?" I didn't think it would be possible, the blades are really that good.
There isn't really any way to objectively measure the quality of a saw cut. All you can really do is say subjectively "nice cut" or "that's kinda rough", etc. I did multiple cuts in various materials both with and without the the stiffener. What I found was that the stiffener made no difference that I could discern in any material or type of cut. I also did crosscuts in chipout-prone materials like birch plywood, both with and without zero-clearance inserts. Again, if there was a difference in chipout it was so small I couldn't see it.
There is something to their claim that noise is reduced. I could consistently get a very minor 1-2 dB diffence with the stiffener when the blade was simply spinning, which is not really much at all. When cutting, however, the stiffener did lower the sound level by 5-10 dB. However, you're talking about 100 db vs 110, well into the hearing damage range. You should be wearing hearing protection anyway. I was and I couldn't really tell a difference.
One effect the stiffener definitely has is reducing the maximum blade height by about an inch. If you're using a zero-clearance insert, you'll lose even more height because the stiffener will hit the bottom of the insert and start lifting it. Forrest says you can remove the stiffener "instantly" if you need additional height, but it's not exactly an instant process. It's just like a blade change, e.g. remove any insert, raise the blade, remove the arbor nut and washer, remove the stiffener, then reinstall the washer and nut.
Based on my testing, I really see no need or benefit from the stiffener. Knowing Forrest, it's hard to believe they'd create and recommend a totally useless product, so I imagine it has benefits in other circumstances. Perhaps some material I didn't test? I also use all full-kerf blades, perhaps the effects are more pronounced with thin-kerf blades?
If you're using thin-kerf or non-Forrest blades, the stiffener may be worth a try. Especially if you get it from Amazon, since you can return it for a full refund (including free return shipping) if it simply doesn't work for you.