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mast up, back stay OK (??), how much tension?

Posted: Sun Jun 12, 2016 8:21 pm
by ChrisC
Yesterday I got the mast up on my C-22; the set up required some thought, but pretty easy once it was all rigged and ready to go.

The back stay seems all right. It's not floppy.

But how much tension? The shrouds are quite tight, which seems proper to me. However, the forestay and backstay have some movement. They are not tight like a piano wire; I can bend them a bit by hand. I have no idea how much tension they should have. The back stay is tightened as much as the fitting will allow. I had to loosen it quite a bit to be able to attach the forestay, and then tightened. The forestay could perhaps be tightened a little, but of course, the mast should be tensioned aftward, not foreward. Unfortunately, the original documentation doesn't help much.

I have the backstay adjuster I can use, but I would like to know the proper tuning before resorting to that. How much tension on the fore and back-stays on your boats? Any thoughts appreciated.

Posted: Mon Jun 13, 2016 6:59 am
by Papax3

Posted: Mon Jun 13, 2016 11:21 am
by ChrisC
Wow, that's a lot of information. Thanks!

To use your musical metaphor, the fore and aft stays are like the lower E string on a guitar--they are tensioned, but with some play.

My question, though, really was a simple one--is there a way of determining how tight the fore and aft stay should be?

The settings are the same as when the mast was taken down1 1/2 years ago. But without the silly rope binding the backstay that the previous owner used, I'm curious if it's in the correct zone.

Posted: Mon Jun 13, 2016 4:58 pm
by Reality
not an expert on sailing, but I do know engineering and most catastrophic mechanical failure comes from trying to make things too rigid. The wingtips on a 787 flex up 15ft during flight. My shrouds appear tight when sitting in the slip with no wind or sail, but I get slack on the leeward side when sailing in a 15knot wind. The local old salt sailors say that's OK.

LOOS & COMPANY Rig Tension Gauges

Posted: Tue Jun 14, 2016 5:55 am
by C22Bob
Nice tool for checking rigging

Image


YouTube video

Posted: Tue Jun 14, 2016 12:13 pm
by CaptainScott
At risk of really agitating the true perfectionists and avid rigging tuning experts I'll toss in my two bits here however in reality my opioin is worth about 1/2 that! LOL!


Here is how I tuned my C22's. AS stated the shrouds are all snugged up nice and tight. A plum bob can be used to keep the mast straight however I just visually confirmed. The shrouds should be snug however as stated above, the Leeward side will appear slack when sailing to wind.

OK, now the port and starboard are nice and snug AND the mast is perpendicular to the boat sitting straight and level.

Typically I'd have the mast up with slight looseness in the aft stay. Seriously not much at all. Not piano wire tight. Remember when running you want the aft stay looser and when beating you want it tighter thus the adjust ability. I'd then simply adjust as desired while sailing.

If your adjustable aft stay is not functioning I'd adjust the aft stay nice and snug and just sail her! Better yet, just make it work! Not much there anyway!

This is not tuning for racing. This is tuning for a day relaxing on the water or spirited sailing. Tuning for racing is a whole new subject.

Also from our main page there is a documents link. Scrolling down there is a large amount of documentation on how to rig the C22.

Enjoy!
Scott

Posted: Fri Jun 17, 2016 11:47 am
by ChrisC
Captain Scott, thank you for your practical advice. I am satisfied with the fore and aft stays being tensioned but not piano wire or rod tight. I can flex them by hand. The mast is not coming off : ). There is no play in the mast itself.

I rigged the C.S. Johnson backstay adjuster with an old boom vang from a dinghy, and that seems to be just fine for providing various amounts of tension. I will eventually upgrade to a better system of blocks and cam cleat, but I wanted to see if this worked well enough with it's fastening point at the empty stern pulpit mount. It seems to be fine.

I hope to get the boat in the water today or Saturday (6/18), then I can really test it.

Thanks everyone for your input. Happy sailing.

Posted: Mon Jun 20, 2016 7:01 am
by CaptainScott
Sounds like you have a great plan!

Hope you made it to the water!


Scott