Submitted on August 18, 2005 by Dick

Question: I bought new and still have a 30 year old Cal 2-29 with the original North main and working jib sails. Could you please direct me to a source on proper tuning of the mast and rigging for a sloop of this size (single set of spreaders with fore and aft secondary shrouds and a split backstay with a bridle)? I am gradually adding several improvements to make sailing a bit easier since, like the boat, I have aged a bit over the years and need to make sure my rig is properly tuned and that I am getting the most out of my sails. I will appreciate any help you can provide.

Thanks, Dick

Answer: Dear Dick,

The first step in tuning your rig would be to make sure that you have the headstay length correct. This will determine how much rake you have in the mast, generally around 2 degrees of aft rake is a nice starting point. To check this you can hang any weight from the main halyard and verify that that were the halyard intersects with the boom it is a few inches back from the aft face of the mast. Another way to check and make sure you have a little bit of aft rake is to stand perpendicular to the mast on the dock and visually see that you have a small amount of aft rake.

Adjust the heastay turnbuckle to achieve this small amount of aft rake. Once this is done, you should ease off the forward and aft lower shrouds (equal amounts on port and starboard sides) until they are just going slack. These are the shrouds that end at the spreader.

Now you want to make sure the masthead is centered over the boat. To do this use your jib halyard to measure down to the same spot on the on port and starboard chainplates. Adjust the upper shrouds to center the top of the rig if needed. Now tighten the upper shrouds fairly tight using a 6" adjustable wrench to tighten the turnbuckles. You want these upper shrouds fairly tight as these keep the rig from falling off to leeward when you are sailing. After these are tight you want to apply slightly less tension to the lower forward shrouds. You can sight up the mast to make sure that it is straight side to side during this process. Adjust the tension on the port or starboard lower to keep the mast straight. Once this is done tighten the aft lower shrouds with slightly less pressure than the forward lower shrouds. Again sight up the mast and make sure it is straight side to side during this procedure. All side shrouds should now be fairly tight to the touch.

Next you should tighten the backstay turnbuckles so that the headstay becomes fairly tight. The tension on the headstay should feel similar to the tension on the side shrouds. Go for a sail and sight up the mast checking if it is straight side to side. If it is not you can adjust the lower shrouds to straighten it out. While sailing upwind sight up the headstay and make sure you don't have excessive sag. If there seems to be too much sag tighten the backstay more.

Don't be afraid to make adjustments, all racing sailors adjust their rigs constantly. The basic things you want are a small amount of rake, upper shrouds tight enough so the rig stays over the boat, lower shrouds adjusted to make the mast fairly straight sideways and enough backstay to keep the headstay tight while sailing upwind. It might be a good idea to lubricate the threads on all your turnbuckles while tuning the rig. A product like Lanacote or trailer bearing grease works fine.

Regards,
Chuck Brown
RIG PRO

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