Com-Pac Yacht Owners Association

General Com-Pac and Sailing Related Discussions => Boat and Hardware Modification => Topic started by: jimbo on July 16, 2019, 05:46:24 PM

Title: stay tension
Post by: jimbo on July 16, 2019, 05:46:24 PM
Is there a recommended tension for the headstay and sidestay.  My manual says "snug" but I would be more comfortable with something more definitive.
Title: Re: stay tension
Post by: brackish on July 16, 2019, 10:11:22 PM
Don't know what boat you are talking about but the tension is based primarily on the the size of the standing rigging.  Determine that and then wade through this data and you will know.  You need  a device to measure it.  As an example my 23 with 5/32" stays has a minimum tension requirement of 350  lbs. on the side shrouds and 500 on the forestay/backstay.  The maximum is whatever the cable will take below its breaking strength factored by whatever the boat will take.  Final setting should be in the water.

https://loosnaples.com/how-to-use-pt-series-tension-gauges
Title: Re: stay tension
Post by: nies on July 17, 2019, 08:34:20 AM
talked to huthins about my 16 stay tension................stays are to be equal in tension, taut ,the stays are to hold mast up and are not to be tuned to breaking point. i tune taut and check with gauge to see all about equal in tension.
Title: Re: stay tension
Post by: curtisv on July 17, 2019, 08:51:31 PM
brak - where did you get the 350 and 500 lb numbers?  I had always heard the generic advice of 10% of rated strength of stay which for 5/32 would be about 300 lb.

In any case if you don't sail in strong conditions then "snug" is the advice.  If you expect to sail in stronger conditions then "tight".  How tight?  Some joke about middle C.  Brak is right about using a gauge if you want to be sure.  I just pull on the stays and get a feel for how tight it is.

Too loose and the rig is sloppy, leaning away from the wind and possibly shaking a bit (very loose).  Too tight and you put unnecessary strain on the chainplates and hull.

One thing you'll notice is if the stays are tight with the mast up on the trailer, they will be loose when the boat goes in the water.  On the trailer the keel supports most of the boat's weight.  On the water, the pressure of bouyancy on the hull supports the weight and the keel is unsupported (unless you run hard aground).  This force is distributed over the hull and bends the hull up a bit.  If you forget to loose the stays before hauling the boat the stays will be super tight.  At that point the stays are trying to keep the hull bend that buoyancy was doing but with all of the force concentrated on the chainplates, so this is not a good thing to do.

Its been 18 years with a CP23 and still haven't bothered to buy a strain gauge for the stays.  So "snug" or "tight" depending on conditions.  Does that add to the confusion?  Glad to help.
Title: Re: stay tension
Post by: brackish on July 18, 2019, 07:15:17 AM
CurtisV got it from the Loos site.  They have a table by wire rope size indicating the minimum or initial tension.  They contend most people set too loose.  That was my case, when I set to "snug" I was half their initial setting recommendation.

http://cpyoa.geekworkshosting.com/forum/index.php?topic=10516.0
Title: Re: stay tension
Post by: Bristol14 on July 18, 2019, 10:06:54 AM
I've always used "snug" to tension my shrouds and stays. Works fine on my '23 and previous boats (CD Typhoon, Bristol Corinthian). Seems like what's most important is even tension and the slight rake others have mentioned. One year my boatyard tensioned my shrouds for me and the tension was so uneven, the mast was bent slightly crooked. I quickly fixed that on my own and never asked them to tune my rigging again.
Title: Re: stay tension
Post by: jdklaser on July 18, 2019, 10:33:52 AM
Snug is the way to go.  We're not dealing with sophisticated fractional rigging where things like prebend for the sails is a consideration.  Keep the stick straight up.  Keep it simple.   
Title: Re: stay tension
Post by: jimbo on July 19, 2019, 05:51:52 PM
thanks all, not looking to complicate things, just want to make sure I'm not doing anything wrong.