Loos gauge questions

Aug 10, 2020
531
Catalina C25 3559 Rocky Mount
I acquired this Loos gauge to help tune my catalina 25 awhile back.
What am I looking for numberwise? I understand the order of tightness amongst the stays/shrouds, how the gauge works.... I was just wondering if there was a preferred target number, or is this tool mostly for comparison to other cables on the boat? such as balancing your shroud tension ?

Thanks!
 

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Jan 11, 2014
12,761
Sabre 362 113 Fair Haven, NY
Typical tensions are based on a percentage of breaking strength, usually in the 10-15% range. I use about 12 %.

Find the diameter of the shroud and the breaking strength. The table on the gauge shows the reading on the gauge and the amount of tension on the shroud. Looking at the quarter inch column, when the gauge reads 32 there is 480 lbs of tension on the cable. Once the tension is set, then it necessary to sail the boat and check the tension to get it tuned correctly. The gauge is useful for getting close to a good tune.

Having equal tensions, port and starboard does not mean the mast is straight or centered, it only means the tension on the wire is the same.
 
Feb 26, 2004
23,001
Catalina 34 224 Maple Bay, BC, Canada
When I had my C25 (87-98) I thought about gauges, but learned that the two sizes of shrouds on my 1981 C25 would require two different gauges. Not worth the $$ so I used the technique detailed in all the Catalina masthead boats' manuals.
 
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Aug 10, 2020
531
Catalina C25 3559 Rocky Mount
When I had my C25 (87-98) I thought about gauges, but learned that the two sizes of shrouds on my 1981 C25 would require two different gauges. Not worth the $$ so I used the technique detailed in all the Catalina masthead boats' manuals.
That's how I've been going about thus far. It's a great write up. I just acquired the gauge and thought I would see if I can improve anything with it.
 
Aug 10, 2020
531
Catalina C25 3559 Rocky Mount
Typical tensions are based on a percentage of breaking strength, usually in the 10-15% range. I use about 12 %.

Find the diameter of the shroud and the breaking strength. The table on the gauge shows the reading on the gauge and the amount of tension on the shroud. Looking at the quarter inch column, when the gauge reads 32 there is 480 lbs of tension on the cable. Once the tension is set, then it necessary to sail the boat and check the tension to get it tuned correctly. The gauge is useful for getting close to a good tune.

Having equal tensions, port and starboard does not mean the mast is straight or centered, it only means the tension on the wire is the same.
Where do I find the breaking strength of the cable?
 
Jan 11, 2014
12,761
Sabre 362 113 Fair Haven, NY
Go to a marine website that sells rigging wire and cable. Look up the size and type you have. You will need to know if the cable is 304 or 316 stainless and if the cable is 7x7 or 7x19. In the description the minimum breaking strength will be listed.
 
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