I have an older 1980 prindle 16. The jib blocks are attached directly to the trampoline straps rather than to shrouds or the hull. I thought this was harmless, but racing on the weekend, I was always luffing the jib a bit closehauled, could never get the windward telltales back, and want to go back to the factory system. Since I don't have the ports, I will just run spectra or wire from the shrouds. Can anyone tell me how far the jib blocks should sit (from the stays)?

Damien

damienb, have you had the opportunity to look at a later model P16? the jib block pigtails are attached through a small hole drilled through the hull just below the ports.



The pigtail is 18" long pull to pull, the problem is that the pigtail must be inserted through the hole and then a slug swaged onto the end of the pigtail as a "stopper", silicone is then applied around the pigtail on the inside of the hull to waterproof, one has to find a method to swage the stopper professionally. I am in the process of renovating a P15 and adding a jib as this boat is a uni-rig, I plan to use the above method to install jib blocks but will have to take boat over to West Marine to have the pigtail stopper swaged onto wire. Once the jib block pigtails are installed a 3/16 or 1/4 inch X 6ft line is attached to thimble at 1 end, line feeds through grommets in center of tramp, (use the aft grommets), and is attached to the opposite thimble using a truckers hitch.

http://www.thebeachcats.c…852&g2_imageViewsIndex=1


HTH

Yes, I don't have the ports or the hole, so will need to go direct off the shrouds. Based on your pics etc it's about 23" from the shroud (18" from the inside lip of the port). Easiest way is probably a 23" spectra line from each shroud to the jib block shackle, and then another spectra line across the centre of the trampoline between the 2 jib blocks.

/Damien

The earlier P-16s pigtail was attached to the shroud anchor pin using a bell shackle. The shackle replaces the clevis pin that connects the twistclip to the anchor pin, or if you wanted to go a little higher up you could put the shackle where the shroud adjuster and twistclip connect.

Ok, so no ports, no hole, then do as you say above, just play with the jib block location untill you are satisfied, using 1/4" low stretch line which I guess spectra is. You could use 3 lengths of line or just 1 with 2 loops tied off at 23" on either end, but do use the aft grommet holes to prevent the jib pulling the blocks away from center. If you don't have grommets in center of tramp you might have to move the jib blocks closer to center so you can get your jib close-hauled.

Well, set it up so that the jib attachments were just on the inside of the tramp straps, and much better tension & jib feel upwind, but I still can't go upwind without the jib fluttering excessively near the top. I do have the grommets, and used the aft holes.

If the leach is fluttering, move the jib leads forward so that your pulling down more on the leach.

--
Ron
Nacra F18
Reservoir Sailing Assn.
Brandon, Mississippi
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The Prindle jib has a line attached to the jib tack grommet, it acts as a downhaul, there is a camcleat just above the tack grommet, the line feeds through the turnbuckle and up through the tack grommet 2 or 3 times to give you 2 or 3:1 downhaul and is then cleated off at the camcleat, this will tension the luff (leading edge) of the jib, crank on the downhaul. The jib blocks create tension on the leech (trailing edge) of the sail, you can play with the adjustment of the jib blocks using the center grommets. The big question is, which part of the sail is fluttering, the luff or the leach?

Mainly luff in the top 1/3. My jib is too long to use the hook for some reason (aftermarket but relatively new jib) so I just tension the halyard and apply a bit of downhaul. Maybe I should change the halyard for spectra and send it through the ring to get a bit more tension on the downhaul.

To create sufficient down-haul to neutralize the flutter, you have to use the "S" hook, just trying to use the jib halyard will not work, you have 2 options, get the jib cut down to size or shorten the upper pigtail. My choice would be to get the jib cut down to standard.

Thanks. Might just check the stay geometry first..., and maybe set it up tied to the shackle/ring before I go modifying the jib. I've also got an older jib with broken zipper. Bet they copied that for the new sail, luff stretch and all.

Vs other cats (Arrows, Nacras, Hobies) I'm making ground downwind/reaching and losing it (&then some) upwind. Should be the other way around right?

dunno about that, downwind you want the sails to act like a parachute, your jib is doing that already because you cannot get the sail tight. The Prindle 16 has 189 sq/ft of sail, the Hobie 16 has 218 sq/ft, so the H16 has almost 30 sq/ft more sail area than the P16, more sail area = more speed. I once saw a P16 rigged with H16 boom and sails and it was incredibly quick, always wanted to try that out.

OK so the jib luff is definitely way too long - probably by 4". Compared it to my old jib and got it tight putting lots of rake on and tying directly to the bridle. Worked way better but the rake was not good otherwise. Why not just shorten the pigtail? Taking length off the foot looks like a big modification, and folding the top down would lose me my leach tension.

That is definitely an option, if you plan to keep the boat. But don't shorten existing pigtail, just order new one to customized specs, it's only $24. Why? lets say later down the road you see an excellent deal on used sails, main and jib, you still have factory pigtail, or say you decide to sell, you let buyer know the jib is after-market and if buyer decides on newer used sails he still has factory pigtail. Also, the Prindle pigtail is a single length of cable with thimbles on either end, then they fold that stay around another thimble off-center (to factory specs) and swage the two pieces together to give you the Prindle double ended pigtail, might be hard to shorten that because it also has the SS ring attached to the lower thimble. Anyway, you decide, but you need to hurry, soon it will be time to sail.....




http://www.murrays.com/mm…de=C-R-R-P&Store_Code=MS

I'll do all that except no Murrays for me, since I'm in Australia. Thanks for the help!

This is all (kind of) sorted now, after sailing with the original jib for 4 months, and fitting the "new" jib last weekend for the forthcoming season.

Naturally, it was not that easy, since with a 4" shorter pigtail, you need a 4" shorter forestay, which I made on the spot. It works better, but now have a big relatively high large jib . I have lost my weather helm, and my jib-main slot is not big enough, so I should move the forestay base forward which will require me to rake my rudders even more to compensate for the helm.

There's a reason people do not modify sail patterns!

Damien