Winch Covers – Why I Learned Pi

Winch cover on the mast winch.  Also firing the canon at dusk.
Winch cover on the mast winch. Also firing the canon at dusk.

Pi – The number π is a mathematical constant that is the ratio of a circle’s circumference to its diameter, and is approximately equal to 3.14159. Wikipedia

In high school I wondered why in the world I would need to understand pi, you know 3.14.  Math and I got along just enough to get through.  Now I know!  I have actually used pi in a practical application.  Very exciting for a non-math type.  I used pi to figure out how to pattern a winch cover.  Winch covers are valuable for protecting those important winches that help give us ability to manage lines under load.  And they have a habit of getting lost or blowing away in a storm.  It’s likely you’ll need to make extras at some point.

Materials you’ll need:

– Sunbrella

– elastic (1/4″ or 1/2″ wide)

– UV thread

– binding tape

– marking tools

There are excellent directions for winch cover making by Jim Grant in this article or in his book The Complete Canvasworker’s Guide.  He uses an inner choker to hold the cover on the winch.  I modified mine a bit by sewing in three or four tabs about 2-3 inches long finished in the top seam and running elastic through the tabs. (You could use shock cord too.)  Be sure to measure the top and the sides so that you have a good fit.  Grant’s article describes how to calculate the top circle using pi.  Use lots of pins or staples to attach the top to the sides before sewing.  I’d mark the top and sides by quarters so that you can line up the marks to make sure you don’t get big bunches.  If it isn’t perfect and you get a pucker or two, I’d still say you succeeded.  Get it done and on the winch so you can go sailing!

Secret Trick:  You may have several sized winches aboard.  It’s not always easy to tell which size gets which cover.  Sew in a small tab of binding tape and embroider or use a Sharpie to mark the size.

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