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Current Replies for Mast Tuning
  Mast Tuning (Hunter)
Posted: 7:14:08 pm on 3/15/2012 Modified: Never

I have a 1984 MKV.

How do you tune the mast?

I have heard of hanging a bucket of water off the main halyard and measuring back toward the mast.  And then there are some hand held apparatuses that very accurately measure the stay tension with what look like fish weigh scales attached.


Hunter van Leeuwen
Whites Lake, NS

  Re: Mast Tuning (JWente)
Posted: 8:25:54 pm on 3/15/2012 Modified: Never
are you racing or cruising?

cruising: make everything nice and tight, go sailing.

start with rake: shift the gear around inside until the boat is level. loosen the back stay.  hang a wrench or somethng heavy from the halyard - with the wrench at boom hight.  Rake is the measurement from the mast to the wrench.  You want 18 to 20".  Loosen or tighten the forestay to get the desired rake.

Next tighten the side stays.  buy (or borrow) a Loos guage which measures tension.  Tighten the uppers.  You need to tighten gradually on each side.  When you are done measure from mast tip to rail on each side to ensure the mast is straight.   Measure by pullling main halyard down to the rail on each side.

Tighten mid stays next, fairly firm.  Sight up the mast track to make sure the mast stays straight and does not start to bend in an S shape.

Tighten lowers next, gradually on each side, to 25 on the Loos guage.  keep sighting up the mast to make sure it is straight all the way up.

2 weeks later check the tension again - the boat bends after time and the stays loosen up.

add sails.  go sailing
There is a tuning guide in the MKV section of the web site that is quite useful.
  Re: Mast Tuning (Scott)
Posted: 6:06:56 pm on 3/16/2012 Modified: Never
There is little that can be added to what has already been written and posted on this topic in the Black Arts section of this site.  Start there and if you have questions after you're set up, come on back to the forum.

Scott Schoeler, Hull 858, "Scot-Free"

  Re: Mast Tuning (Hunter)
Posted: 6:34:01 pm on 3/17/2012 Modified: Never

I read the black arts on rigging;

"The next issue is to get the mast centered in the boat (side to side). I add a spare sail slide in the mast track (put it on before you feed the slides for your main so it sits above the other slides), then I use the main halyard to hoist the slide, with a tape measure attached, up to the top of the mast."

What "slide" is the author referring to in this text?

Hunter van Leeuwen
1984 C&C 27 MKV 006
Whites Lake, NS

  Re: Mast Tuning (Scott)
Posted: 7:38:43 pm on 3/17/2012 Modified: Never
I presume the author is referring to a spare sail slug.

Scott Schoeler, Hull 858, "Scot-Free"

  Re: Mast Tuning (Steve Reid)
Posted: 8:49:22 pm on 3/17/2012 Modified: Never
I am the author of the piece in "Black Arts".
The reason for putting in a spare sail slide is because, the Main Haylard does not run on the centre line of the mast it is offset to either port or starboard, dependoing on how your mast was set up. If you just rely on hanging a tape measure on the main haylard and hoisting it to the top of the mast you will end up with you mast head not being in the centre of the boat when the measurement is equal from side to side. The spare slide is above all the other main sail slides so you can use it to check the position of your mast any time you want during the season.
A word of caution about the tension setting of 25 that Jim quotes. There are 2 types of Loose Gauges, the regular and the Pro, the readings on each are different. Jim (and I) use a Pro.

Steve Reid
Still Knot Working Mk V #75