Smoothing Lathe Whip

IMG_3324As I worked on a project for the July/August issue of 360 Woodworking, a portion of which is turned, I ran into a common problem when working at the lathe. The problem comes about when turning long thin pieces. It’s known as whip wherein centrifugal force causes a piece bow slightly outward. Two things happen when you work against whip. One is that the piece turns out of round, and the second is that the surface is nowhere near smooth, even for most woodworkers when using a skew.

The turning portion of my project is in excess of 35″ in length, and it’s only 1-3/8″ in diameter in places. I could take the time to set up a steady rest to hold the stock more uniformly as I turn. For a single piece, though, that’s too much setup. I sometimes use a leather glove to help steady the turning, but even then a smooth surface is more of a dream. (At least it’s not a nightmare!)

IMG_3325That means there is additional leveling and smoothing needed. As I encountered this problem, I decided to run a bit of a contest. In my arsenal of tools was a cabinetmaker’s rasp, a Shinto rasp and a piece of Abranet HD. Which tool would be the best? The answer, at least from my perspective, may surprise you.

I’m a huge fan of the Shinto rasp. (So much so that my business partner often makes fun of me.) This time, however, Shinto loses out. Even though the openness of the Shinto did not load up with scrapings – something that the rasp immediately did with the lathe up to speed, so it was tossed from the competition – it seemed to be less aggressive than when I’m using a Shinto to shape cabriole legs. Both of these tools are workhorses in my shop, but just not the tool I’d choose for this task.

The winner of my impromptu contest was the Abranet HD. The stiff nylon-mesh backing of the HD made it easy to use to level rough surfaces. It’s a great product to have in the shop for anytime you need an aggressive abrasive, especially when turning. (As would be the case with any of the tools selected for my contest, further smoothing was necessary.)

Got another tool in mind that would have been up to the competition? Leave a comment to tell me about it.

— Glen D. Huey

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5 thoughts on “Smoothing Lathe Whip

  1. Just say, “No” to the Shinto!

  2. Put your lathe on its slowest speed, the use a block plane. the extra registration helps control whip. Practice on scrap until you find the right angle and plane cut depth to work.

    1. Jim,

      I’ve used that technique before, but it was primarily to smooth the surface of a larger-diameter piece. No whip involved. I wish I had thought to try it here.

      1. I agree Jim, with a well sharpened (@ least 3200) micro-beveled short sole plane (ie. Block plane) used at a approx. 30 degree bias to the grain of tight growth woods turning below 600 RPM produces exemplary results. Beware the temptation to increase depth of cut or take the turning too a small diameter because of the effectiveness of this technique. Reduce RPM, use a smaller plane or even regrind the sole of an old plane to a slightly smaller radius than the curve required. (Essentially a boat builders razzee). For delicate work approach the line as if you were a ghost.You want to be the subtle intuitive guiding hand of a Swayze, not the abrupt and alarming shoulder tap of a Betelgeuse blunder. Slow, sharp, sure and steady. Sincerely Simon

  3. Shinto …..sounds like something they get you with in prison …..LOL

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