So I just looked at the old owners manual and it shows the procedure for the beam straps but not the internal beam castings nuts. All of my searches do not address the beam castings for the nuts. My cat does not have straps and only has the internal castings. So the manual shows 16-18 foot pounds for the straps but nothing for the internal beam casting nuts. What is a safe torque for the internal beam casting nuts (without the straps). Thanks for your time. Kevin

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Kevin
Wantanacra
VA Beach, VA

Nacra 5.0
Nacra 5.2
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I've never seen a setup on the old boats with just the casting used and not straps. The casting is just a clean way to keep the beams from rotating as far as I know. I've just used the same 18 ftlbs for the bolt going through the internal casting. Have your hulls been refurbished? Maybe the previous owner had to cut off the old bolts or stripped the holes and just filled the holes and put gel coat or paint over the holes.

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Craig
Windrider Rave Hydrofoil
Nacra 5.2 Restored and heavily modified
Nacra 5.2 (one under restoration)
Nacra 5.7
Nacra 5.8NA
SoCal
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Good question. The boat is an 83 with no straps and has 3/16 diameter studs that come out of the hulls for the beams. Does not look modified but who knows. The boat was used and abused before but all the studs are firm and have no play. I just cranked them down and will check the torque here in a day or two. Kevin

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Kevin
Wantanacra
VA Beach, VA

Nacra 5.0
Nacra 5.2
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That is really odd. I've seen quite a few Nacras of that vintage now and I've never seen one without straps. I'm not sure I would trust it. All the literature from that time indicates straps. They didn't add the casting until 1984 or so. Is there a port behind the beams that will let you see into the hulls and confirm that the holes just a haven't been glassed over?

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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The only port is the aft port. The gelcoat appears to be original. I will get my camera and flashlight and take a picture to see if it was altered. One would think if it was there would have been a port cut forward. Kevin

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Kevin
Wantanacra
VA Beach, VA

Nacra 5.0
Nacra 5.2
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Took the camera and snapped a picture or two of the inside where the beams mount. There appears to be no modifications to any of the glass on the inside. The glass does not show where the straps would have been mounted as the glass looks factory. So as for modifications it appears there were none done. Kevin

Happy Easter!

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Kevin
Wantanacra
VA Beach, VA

Nacra 5.0
Nacra 5.2
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Kevin,

I'd be interested in seeing a picture of your setup. You mention casting nuts, but my 4 nacras have a bolt that goes through rounded bottom casting that is about 2" long (fore and aft) and 3/4" wide. There are no studs coming out of the hulls. This small casting sits just inside from the crossbeam end about 3/4" and butt against the bolt rope channel inside the crossbeam to keep it from rotating.

Are your studs coming out of the hull saddles? If so, how many per saddle?

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Craig
Windrider Rave Hydrofoil
Nacra 5.2 Restored and heavily modified
Nacra 5.2 (one under restoration)
Nacra 5.7
Nacra 5.8NA
SoCal
--

Yes the studs come out of the hull saddles. There are two of them on each saddle point for a total of eight. The beams slide then slide over the studs and then I use the casting (half moons) to slide inside the beams up against the bolt rope channel. I then use the 3/8 nut to tighten them down. It is just like what you explain but instead of a bolt going into the hull saddle the studs come out with the beam castings going on them. I can send you a picture later today if need be. Kevin

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Kevin
Wantanacra
VA Beach, VA

Nacra 5.0
Nacra 5.2
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That is same setup that mine had, no straps. It was sail number 671 if i remember (or maybe 761) . An 83 with no inspections ports at all. So you slide the saddles into the beam rounded side down and then lower the beam over the studs trying to get the studs to find the holes in the saddle so that they end up sticking out the top. Then you hand-start the nuts on the studs and slip a socket over them. Then you put an extension on your socket wrench and stick the extension through the hole in the top of the beam and slip it into the socket which is already on the nut and then torque it to 18 pounds. File any burrs off of the end of the crossbeam before you do it for personal comfort. The idea was to make the boat look simpler by not having the "complicated" bolts and straps exposed. CHECK THAT THE NUTS STAY TORQUED, one of mine loosened (or was never tightened by the dealer) and the crossbeam started to move and strip the stud.

Flyhull, thanks for your reply. I was thinking I had some rogue Nacra. Thanks Kevin

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Kevin
Wantanacra
VA Beach, VA

Nacra 5.0
Nacra 5.2
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I'm a little late to the party here, but my '83 5.0 is exactly the same. No beam straps and only has the half moon castings.







Edited by matt922 on Apr 22, 2014 - 07:52 AM.

I wish i still had mine so i could take a picture like that, they are great boats. As long as you have the wrench out, put a mast rotator on it for 2 reasons: 1) force over-rotation and sheet in hard going upwind in a blow to flatten the sail and 2) force over-rotation going downwind so you tack deeper while going faster than any of the boats behind you.