[RichH]

Go to http://www.riggingandsails.com/pdf/selden-tuning.pdf and look for the 'meter stick method' of setting/verifying correct rig tension - without a tension gage. Proper rig tension is important for how your jib/genoa sets and takes its proper shape; and, is quite important with regard to 'pointing ability'. Your 'lowers' numbers seem too loose. Most boats need ~12% backstay tension for sailing in or less than 12Kts apparent so that the forestay sag is under control.

Sometimes even 'brain surgeons' make mistakes.

 

[RichH]

ps as an aside note...I prefer slightly LOOSE than too tight...too tight will cause more damage and stresses in hardware, plates, decks attachments etc...than slightly lose...

also racers for the most part have slightly loser rigs(for the most part) dock side tune than cruisers and daysailors...

Im a racer and aggressive long distance cruiser, I often to validate my 'settings' by using a rig tension gage while underway and when 'hard over' so that the caps and lowers when at the heel angle I normally 'max-out' at doesnt go much or often go beyond 30% tension - 30% is where stainless rigging begins to 'yield' or develop permanent 'stretch'. Also constant cycling the rigging beyond 30% leads to rapid premature metal fatigue in the wire and end fittings, as well as chainplates.

 

[RichH]

Sorry to disagree but standard / typical boat design for rigging and spars DOES approach standard / recommended 'numbers' on a tension gage for the BASIC rigging settings. Every mast supplier will give you these numbers which are typically at ~12%UTS for sailing in moderate conditions and which equates to a normal accepted safety factor (FS) of a minimum of FS≥3 for offshore boats, ≥2.0 for coastal design and ≥1.5 for inshore.
Such 'numbers' are derived typically by doing theoretical calculations or by actual measurement of the resultant rig forces on the caps, and lowers, etc. on a boat at a ~45° angle of heel, and then multiplied by the intended --SAFTEY FACTOR-- of the design type .... all to insure that the rig doesnt stretch beyond the limits of plastic deformation (yield) which is typically ~30% for 300 series stainless and approximately where the all important fatigue endurance limit for 300 SS also occurs.
So if you want to argue about 'numbers' be prepared to argue with all the spar and rigging manufacturers as these BASIC numbers are in alignment and agreement with standard accepted broadscale precision static and dynamic structural practice ... then you can tweak all you want, but ultimately you will arrive quite close to these 'numbers'.
Seldén is an example of a leading spar supplier http://www.riggingandsails.com/pdf/selden-tuning.pdf ... take a look their manual at all those recommended GAGE % NUMBERS as the basic settings, as these settings will be VERY close to the actual on-the-water tensions to accomplish the minimum resultant to-the-boat stress induced loads AND to keep the mast in column AND to keep the forestay/headstay at the proper catenary sag which the sailmaker also depends when cutting a sail.
So in conclusion all three entities - boat designer, rig/spar manufacturer, and sailmaker all design, engineer and manufacture based very closely to these 'numbers' and strengths and inherent factors safety.
There ain't NO other way to do this ... for sailboats, for aircraft, for cars/trucks, for anything that 'moves' and that carries people.

;-)

 

[RichH]

My mast has a ton of prebend in it, 8-10" I assume, This may well be from me setting the rigging to numbers. Im thinking in the future i should set the forestay first then shrouds then rearstay?

Any typical mast, not originally intended for radical 'mast bending', should have only a ~3/4" pre-bend for a single spreader rig. If a multi-spreader rig, should only have 1/2" pre-bend for each spreader set.

Are you talking pre-bend here to increase mast stiffness? .... or are you mast bending to radically reduce mainsail draft/flatten?

 

[RichH]

This is nonsense. Every boat has its own prefered amount of prebend, and it has nothing to do with the number of shrouds. You might be able to argue that it has something to do with mast leingth, but even that isn't really the case.

I couldn't find a different link for the North Tuning Guide for the Catalina 22, but this is from that...

The mast rake is probably the single most important element of tuning your boat. Note the mast rake should vary from fixed to swing keels with swing keels having slightly less rake.

Start with boat sitting on its lines in the water. Hang a weight from the end of the main halyard and cleat off halyard with weight and shackle 12" below the boom. Measure distance from the aft face of the mast to where the halyard crosses the boom. This measurement should be 8" for fixed keels, 6-7" for swing keels. Adjust the headstay turnbuckle to achieve desired measurement.

Tighten backstay until snug, no slack. Remove weight from halyard, attach a tape measure to halyard and haul to top of mast. Measure from side to side tightening or loosening upper shrouds until mast is centered.

Now start tightening upper shrouds until they have show 28 on the gauge. Tighten forward lowers until they show 24 on the gauge. Tighten aft lowers until they are 24 on the gauge too. To measure shroud tension use a Loos Model A Tension Gauge. The end result here is to have the mast straight fore and aft with a small amount of rake to give the boat some "bite" upwind.

Prebend and mast rake are entirely different things.

Prebend is a structural means to induce mast STIFFNESS and resistance to induced harmonic vibrations (by changing the 'natural frequency' of the mast. Prebending increases "I" to the 'third power" - a function of stiffness.
All sailmakers cut the mainsail to the expected amount of normal prebend.

Rake is the vertical angle of the mast w/r to fore and aft to the horizontal plane and is set the CLR/CE AND dynamic (underway) balance of the helm.