I am getting ready to do a spinnaker for my NACRA 5.8, and would like to know where I should drill the hole (s) in the bow for the “stay lines?”
My current plan is to go with a 3/8th inch hole with a piece of SS tubing epoxied in to prevent wear. Also, I am thinking of using “am steel” line for the stay lines, any other recommendations?
I would have done this a bit simpler and drilled a 1" hole. Tape one side and fill well with thickened epoxy, making sure you get a solid fill inside the hull to bind to the hull/deck and spread loads. When dry, I would do a smaller hole in the thickened epoxy for the line. Regular 5mm dynema/spectra will do nicely, and I would be more concerned about wear on the line than on the epoxy. This is the way our Tornado is done, and it works very well.
When I put the spin on my Nacra 6.0, I just installed an eye bolt (3/8" diameter?) about 1.5" back from the bow, about 1" down from the deck. The glass is really thick here, and will handle the load fine. I put a rubber gasketed washer on each side of the hull where the bolt went through, and made sure to use 5200 around the hole to prevent leaks. I never had any trouble. I would recommend New England Ropes- Endura 12 line in 1/8" for the spin bridles. I have used it, and it is great. I can splice it if you'd like as well (no knots!), or you can just use a bowline. There is no need to use a purchase on the line, as a single one will be more than ample for the load. PM me if you want more info.
Worst case, I would epoxy/polyester resin in a piece of fiberglass arrow shaft to seal off the hole. The stainless will not stay in place very well because of the drastic material propery differences between stainless and fiberglass.
How about drilling no holes in the hull? The Tiger uses the same area that the bridle wire goes. It seems to be a very strong area as it is really designed to take a lot of load.
Line - Think about using Vectron instead of Amsteel. I think that Amsteel is Spectra. It is a really good choice after it is stretched but the Vectron will stretch way less. I use Vectron for that application and like it.
I have thought about that as well, and that was the original plan.
The reason I askled, is that many of the retro fits I have seen with this apllication has been with holes drilled through the front of the bow to hold pole centered on the boat, and to keep the pole from flexing when under load. As for the pole flexing, I beleive that the NA bridle foil will solve that problem.
Any other thoughts out there?
Also, is there a need to raise the bridal foil a few inches?
How about drilling no holes in the hull? The Tiger uses the same area that the bridle wire goes. It seems to be a very strong area as it is really designed to take a lot of load.
Line - Think about using Vectron instead of Amsteel. I think that Amsteel is Spectra. It is a really good choice after it is stretched but the Vectron will stretch way less. I use Vectron for that application and like it.
Later, Dan
The problem with doing that on the 6.0NA is that the pole is already SOOO low because of the bow foil that if you run the wires all the way back to the bridle tangs that they're at a rediculous angle. They really must go to the bow on the 6.0NA.
I never had my kite out in extreme conditions - but my bow foil was at standard height and my pole was unsupported except by the end pole bridle wires and being lashed to the bow foil...although it had a rather large cross section. However, most of the 6.0NE (New England) guys that converted their boats to spinnakers DID extend their bridle foil wires several inches and ran diamond wire trusses on their spinnaker poles to give them additional support.
Mine was already configured for the spinnaker so I didn't mount it. However, you should mount it as per the design of the spinnaker. With the spinnaker hoisted and the tack pulled out completely, you should be able to grab the luff with one hand, make a fist around it, and rotate your hand 90 degrees before the spinnaker luff becomes tight. As a general rule of thumb, if your spinnaker hoist point is higher than 1/3 the distance from the hound to the top of the mast, you will need to be cautious to maintain mainsheet tension when the spinnaker is up. Our F18's are about 2/3 the distance up.
Jake Kohl
Re: NACRA Holes
[Re: Jake]
#69201 03/15/0611:43 AM03/15/0611:43 AM
One would think so, but shouldn't the main the goal be: sail as low as you can and still fly a hull? I do think better sail trim would make the boat pictured faster, even at the angle they are sailing.
BTW, sometimes still pictures do not tell the whole story - he could be dumping the main in a puff (which is not exactly the right thing to do in spi sailing, either - dumping the traveller would be less expensive ).
In my opinion, the guys in that picture are WAAAAY to far eased on the mainsheet for effecient speed. On many boats, the mast would not support such pressure without support - but that Tiger mast is like a telephone pole.
The picture was ment as an example of a very loose mainsheet. I know one of the sailors onboard and he is very competent, so I guess there was something going on before the picture.. Still a very loose mainsheet tough
As for stretching the bridle stays for the tip of the bowsprit back to the forestay fittings, I dont like it. You need loads of prebend, compression (and the possible buckling) will be larger and the resultant force on the forestay fitting will be in a different direction than it was designed for.
Bill, you are right, depending on what cat you are sailing. On the Tornado we let out about 15cm on the traveller when looking for power and let the downhaul off. Not touching the outhaul or rotation much. When the wind gets stronger, we let the mast rotate fully, and use the traveller to depower if neccesary. As long as you trim the main so leech telltales are flying 50% you are doing well. The main in the picture can not have an efficient exit for the wind and drag must be large.