Mast tuning

Submitted by ducaud on Mon, 01/19/2009 - 10:37
I have just a purchased hull # 3423 and I have some questions regarding the FS tuning guide: "The measurement from the top of the mast to this point should be between 28’ 4” and 28’ 5 ½”. The next step is to measure the “slop”. Do this by pushing the mast forward until the shrouds prevent it from going any further and measure at the same point on the transom. This measurement should be between 2” – 5”." Is the first measurment of 28'4" to 28' 5 1/2" done without much tension from the forestay? Mine measured 28' 10", I shortened the shrouds since they were pretty loose and I got to 28" 7" To raise my mast I attach a rope to the forestay and cleat the rope once the mast is up. then I attach the jib halyard to the bow eye to bring the mast forward using the jib halyard winch, then I attach the forestay to the forestay extension. If the mast rake is at 28'4" to 28' 5 1/2" I am not able to conect the forestay extension to the forestay. I am about one inch short of it, even with toggle plate all the way up. I tried the adjuster under the front deck, but I don't want to leave less than six turns on each side. What am I doing wrong?
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Comments

I don't know if you are necessarily doing anything wrong at this

Submitted by bigpapaporsche on Mon, 01/19/2009 - 17:23.
I don't know if you are necessarily doing anything wrong at this point! The first step is to set the mast to rear deck dimension has you have. The next step is to measure your jib! This will determine what cut jib you have, and the corresponding rig set-up. The jib measurement is very important in determining which Rig your boat is designed for, IE Loose, Snug, or Tight. To find this measurement simply measure across the jib's width, parallel, and at the top batten. This measurement is not exact, and are approximate and can vary from sail manufacture to manufacture. The approximate measurements are, Loose Rig Jib = 35 inches, Snug Rig= 38 inches, and Tight Rig= 40 inches. I know that if the Rig type, LR, SR or TR doesn't match the Jib's cut, performance will suffer. I know for example that our boat is set-up with a Loose Rig, with a jib measurement very close to 35 inches. I have found another boat with a jib that measured 33 inches. You can see these dimensions are approximate and ball park. Once you know what Rig type your boat is set-up for you are ready to adjust the forestay. I suspect your boat was set-up as a Tight Rig by the previous owner, and that maybe why you are having trouble attaching the forestay. You will need more torque, than the Jib Winch can produce with the winch handle to connect the forestay, Most people use a 3/8 drive ratchet to tighten the forestay, since the handle will brake with to much effort applied. I know the TR/SR are very popular and there are probably many boat using these set-up with the wrong Jib sails at the expense of performance. I would recommend that you verify the JIB measurement, per above and then set the rig type. If you do verify the jib measurement as a TR, then try use a 3/8 inch drive ratchet to tighten the forestay using a tension gauge to adjust and insert the pin. If this doesn't work then you need a extender link. Let us know what you find out.

Thanks bigpapaporsche, When I do first part, which is to measure

Submitted by ducaud on Wed, 01/21/2009 - 15:05.
Thanks bigpapaporsche, When I do first part, which is to measure the mast rake according to to the information posted on the Schurr sail site, It gives me 28' and 9" from mast to transom. According to their site the distance should be between 28' 4" and 28' 5 1/2". The only way to attain this measurement would be to shorten the shrouds. Is there any other way, or is it fine that my mast rake is about 3 inches over the specs? With regards to my sail I measured the width of my Schurr sail at the top batten and is 33 inches. which if I understood your note is a loose sail. If that is the case then I don't need to tighten the forestay that much, which in turn will help bring the rake closer to specs, but it would make even harder to connect the forestay with the forestay extension at the bow eye. What's next? get an extender link for the forestay link? Thanks again

It sounds like the shrouds need to go shorter.

Submitted by sawyerspadre on Wed, 01/21/2009 - 18:23.
It sounds like the shrouds need to go shorter. Do you have holes left to shorten? Did you find out if you have snug or loose? I don't know if Schurr made tight. I had Schurrs with my boat from the 80's and they were loose rig. In that case the toggle is "active" and not pegged to one end as it is with snug or tight rig. Phil Scheetz FS 4086

Phil Scheetz

FS 4086

Fleet 163, Nockamixon Sail Club

It sounds like the previous owner had the tuning all messed up o

Submitted by bigpapaporsche on Thu, 01/22/2009 - 10:12.
It sounds like the previous owner had the tuning all messed up on your boat. It must have been fun trying to sail a boat set-up this way. 1. Remember the boat manufacture determines the basic specifications, in this case FS sets the rake measurement at 28'4" to 28'5.5." The measurement is done in the relaxed position, ie no forward pressure on the mast.The sail manufacture determines his fine tuning specs. 2. Alway follow the recommended specs, in this case the mast rake, or your boat won't handle as designed, and it won't be as much fun to sail. 3.With the jib measuement you have (33") your boat is set-up has a Loose Rig. 4. I would recommend that after you adjust the shrouds and get the rake set as close as you can and the forestay still won't connect that you contact FS to determine which extension link will be required. This will give you an oppoprtunity to also confirm your nmeasurements and procedures. They are extremely helpful! 5. Once the forestay is attached properly, you can adjust the mast slop. Simply push forward hard on the mast and re-measure the mast-to-transom dimension, the slop is the difference, spec is 1-3." Our boat is set at 1 inch. 6. Finally, mark the pin holes with white paint so you don't have the remember them the next time you put the mast up! Also put rigging tape around the pins and cotter pins so you don't rip your sails.

Thanks to both bigpapaporsche and sawyerspadre for their help, y

Submitted by ducaud on Fri, 01/23/2009 - 10:49.
Thanks to both bigpapaporsche and sawyerspadre for their help, you were both right on all counts. My jib is loose and the boat was incorrectly set up. I have to shorten the shrouds, to solve the forestay cable issue, I have purchased a 3 inch forestay extension from Flying Scot. Thanks again Juan