Mast stay tension

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Mast stay tension

Postby Wayne G on Mon Feb 13, 2017 1:14 pm

I have been slowly tuning the stays so that the leeward one does not go loose, but dont want to over-tension.
The stays are now at 320lbs when measured with a Loos gauge and the leeward shroud still goes a little slack in about 10 knots of wind. The Loos gauge suggests 420lbs for the 5/32 stay but I am concerned that this is too much. Any suggestions would be appreciated.
Wayne Gray
Orlando Florida
Wayne G
 
Posts: 61
Joined: Thu Jul 14, 2016 11:19 am

Re: Mast stay tension

Postby Shudoman on Thu Feb 16, 2017 9:39 am

Hi Wayne,

I struggled with shroud tension too. My first sail I had it way to loose and the lee shroud was flopping around like limp spagetti. My solution was to find the tension where I could still erect the mast and have it seat properly by pulling hard on the jib halyard. When I got my shrouds too tight I could no longer get the mast to seat properly in the tabernacle. I start to see slack in the lee shroud at about 12-15 knts. I read this technique somewhere on the board and if memory serves me right John endorsed it (don't quote me on that... I have a bad memory). I do know that based on the different videos posted by clc that they don't loosen and retighten the shrouds between trailering. They leave the shrouds at the sailing trim while the mast is down on the trailer.

Regards,
Bill
Shudoman
 
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Re: Mast stay tension

Postby Wayne G on Sat Feb 18, 2017 2:24 pm

Hi Bill,

That did the trick. The shrouds are now set so that the mast needs a little persuasion to seat the last couple of inches into the tabernacle.
I was out this morning in pretty gusty conditions (12 knots steady gusting to 15 according to the forecast). The leeward shroud was definitely looser than the windward but always stayed taut.

Really enjoyable sail this morning until the main sheet block swivel base pulled free. It was a bit hairy for a few moments as the wind was fresh and the shore was looming, but I got the sail down without problems and motored back to the dock.

I'm thinking of mounting the swivel base to a 3/4" wood block screwed through the deck into the centerboard housing cleats.
Wayne Gray
Orlando Florida
Wayne G
 
Posts: 61
Joined: Thu Jul 14, 2016 11:19 am

Re: Mast stay tension

Postby Bflat on Sun Apr 23, 2017 3:27 pm

Wayne G wrote:Hi Bill,

That did the trick. The shrouds are now set so that the mast needs a little persuasion to seat the last couple of inches into the tabernacle.
I was out this morning in pretty gusty conditions (12 knots steady gusting to 15 according to the forecast). The leeward shroud was definitely looser than the windward but always stayed taut.

Really enjoyable sail this morning until the main sheet block swivel base pulled free. It was a bit hairy for a few moments as the wind was fresh and the shore was looming, but I got the sail down without problems and motored back to the dock.

I'm thinking of mounting the swivel base to a 3/4" wood block screwed through the deck into the centerboard housing cleats.


A while back I expressed concern here about the possibility of the mainsheet block pulling out. The verdict was that it had not been a problem. Could you please say what length screws you used that pulled out?
Thanks,
Bob
Bflat
 
Posts: 204
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Re: Mast stay tension

Postby Wayne G on Mon Apr 24, 2017 5:33 pm

From memory I believe I used 1 1/2" #10 wood screws but the issue I had was that the swivel base holes did not line up with the centerboard trunk cleats underneath the decking , which resulted in the block being attached to just the 1/4" plywood decking.
I resolved the issue by resining a 3/4" x 2 1/4" diameter base to the deck and then screwing the swivel base to that.
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Wayne Gray
Orlando Florida
Wayne G
 
Posts: 61
Joined: Thu Jul 14, 2016 11:19 am

Re: Mast stay tension

Postby mark48 on Tue Jul 03, 2018 9:48 am

Greetings all PS builders,

I'm at the point of rigging my shrouds.

The gap between the chain plate and the CLC supplied shrouds is smaller than any appropriate turnbuckles I can find so I'm considering either (a) shortening my shrouds to fit available turnbuckles - regrettably messing with my professionally rigged shrouds, or (b) attaching shrouds to chain plates with the CLC supplied synthetic spectra frapping. That choice has driven me to the 'net to learn about frapping. My questions:

* How does one tension the spectra when wrapping the material between shroud and shackle such that the shrouds are sufficiently tight and evenly matched? Likewise, how does one adjust that tension to get it "right?" (I'm also learning about the application of a Loos gauge here.)

* And when I google "frapping in sailboat rigging," the responses all seem to involve much bigger boats and the use of winches to tension shrouds - and it's difficult to follow what knots are being used to secure the final product. Any specific advice or experience would be most welcome.

Thank you all,
Mark

Mark Nunlist
Lebanon, NH
mark48
 
Posts: 95
Joined: Fri Jun 28, 2013 9:55 pm

Re: Mast stay tension

Postby Shudoman on Tue Jul 03, 2018 10:07 am

I too didn't have enough room between the chain plate and the shroud.

There is another option. I moved the shroud attachment points on the mast up about an inch or so. It was enough for me to use small turnbuckles.

Regards,
Bill
Shudoman
 
Posts: 135
Joined: Sun Feb 15, 2009 10:31 pm

Re: Mast stay tension

Postby Wayne G on Tue Jul 03, 2018 6:53 pm

Bill,

I wish I had thought of your idea of moving the pad eyes further up the mast before I re-swaged my shrouds.

I also have turnbuckles to adjust the shroud tension but I do like the look of the frapped shrouds and wish I knew how to frap both shrouds evenly and with sufficient tension.
Wayne Gray
Orlando Florida
Wayne G
 
Posts: 61
Joined: Thu Jul 14, 2016 11:19 am

Re: Mast stay tension

Postby Wayne G on Sun Jul 08, 2018 3:27 pm

I went ahead and removed the turnbuckles and lashed the shrouds to the chainplates.
Until I started the lashing process, where the line is pulled taut on each turn, I didn’t realize that this is effectively a multi-pulley system with the mechanical advantage increasing on each turn for the 1st 5 or 6 turns.
The shrouds are now very tight (possibly too tight). On the Loos gauge they now measure ~28 compared to 25 when secured with turnbuckles.

I used 3mm line as I think it looks better than the smaller line supplied with the kit.

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I did also experiment with adding shims in front of the 3/4” block at the base of the tabernacle in order to increase the shroud tension.
With about 3/8” additional shimming in front of the 3/4” block, once the shroud was lashed to the chainplate and the shims removed I was unable to raise the mast fully because the shrouds were so tight . While ultimately I tensioned the shrouds with just the 3/4 block this did demonstrate that the tension can be adjusted up by re-lashing with additional blocking.

Lazlo writes in link below from the CLC builders forum on how to frap or finish off the lashed line.
https://www.clcboats.com/forum/5/thread/38969.html
Wayne Gray
Orlando Florida
Wayne G
 
Posts: 61
Joined: Thu Jul 14, 2016 11:19 am


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