The annoying questions begin - (Nacra 5.2)

i always have problems finding this as it's in the technical gallery and i expect to find it in the downloads

it is downloadable pdf file of the nacra manual about 1985

it is earlier than the one on the nacra site which seems to be about 89-91

http://www.thebeachcats.com/performance/Nacra-printed-1985a.pdf

the 5.2 was made from 1975-1987-??? which were pretty much the glory days of beachcats and it went through quite a few changes before it was eventually replaced by the lighter/longer/wider/more sail area, nacra5.5

(the 5.5 being lighter than the 5.2 meant that nacra sold it in 2 versions. 1 for solo use without a jib and the other with a jib for crewed use)

one of the major changes over the 5.2's production life was the mast spreaders going from straight to swept

straight spreaders meant diamond wires, which allowed control of the mast's sideways bend characteristics. mast bend control in conjunction with mast rotation control was at the time considered an important tuning option. BUT rotating the mast to anything less than the ideal aerodynamic position seems to have cancelled out any benefit achieved by controlling the jib slot size

so when in the early 80's the tornado guys discovered that by raking the spreaders and really cranking on the downhaul they could bend the mast backwards and depower the sail more efficiently than releasing mainsheet straight spreaders were history

pretty soon all the cat makers changed from straight spreaders to swept spreaders and redesigned their sails to cope with the huge downhaul forces required

so if you have a straight spreader 5.2 ignore all the books that say to depower the sail by hauling on downhaul. the stock downhaul system won't give enough pull and the stick sail won't cope with 15 to 1 systems [email][/email]

edited by: erice, Jul 09, 2009 - 03:31 AM

Hey Turbocat, thanks for the picks! I just came back from one of my first decent sails on the 5.2 in 13 knot winds. The boat performed beautifully!

I did notice that the eyese holding my barberhauler pulleys were pulling out of the hulls however. It looks like the guy that installed them just rivetted them to the hull without any backing plate or anything (argh). I'm just going to move them to the front beam like on your boat. Looks like I get to learn a bit about epoxy and gelcoat now.

Erice, thanks for the info on the downhauls. I was wondering about the stock sail handling that much tension. Good to know before I wasted a pile of money on something that wouldn't help me.

Anyway I also managed to dump the boat and right it using the righting rope thrown over the top hull. Wow did it come up easy compared to a Hobie 16. One thing I did notice though was that there was a fair amount of give in the bottom hull as I walked along it. No cracks or anything, the hull just distorted a bit where I stepped and bounced back when I stepped off. Is this normal or should I be concerned?

Regards,
Dave

the hulls on the 5.2 have a lot more surface area than the h16 but have to weight about the same to be competitive with a h16, so they are pretty thin. esp. early boats with out the foam core

walking on them after a capsize does feel a little freaky however they seem tough enough

DON'T, however make blasting up onto the beach hobie style your normal beaching procedure or the hulls will eventual crack up

hobies have very thick bases and a strong triangular profile as they were designed for this, nacras and supercats etc were not

but those big round hulls support weight better than the vee hull on the h16

video from sunday with 3 adults and 2 children on a 5.2 in very little wind and no jib. probably 230kg, 500lbs and clipping along fast enough that the lubbers were happy. i suspect a h16 would have been a bit of a pig with that weight, though you would have been able to keep the jib on

http://www.youtube.com/watch?v=mZ0WhsOR0Ds

early 5.2's had free floating universals? between the rudder cross-bar and the pintles. like all universals there is a position where they can bind and refuse to steer the boat. eventually nacra welded the parts together at a fixed angle. these can be bought from murrays...............or........you can simply lockwire the halves of the universals into the correct position with lockwire. experiment with string if you have to, there is very little loading and all you are trying to do is stop them rotating around to the binding position[email][/email]

Yeah, mines a 1981 so it is just fibreglass, no foam.

I definitely can't be blasting into shore where I am. I sail in the canadian shield area and it's only about 10 feet of sand and then you run into granite. 🙂

The hulls seem to be a lot more stable than the 16s too.

Not sure what you are referring to as far as free floating universals. I have a very similar system to what TurboCat shows on his pics above. Except the outboard pulley is rivetted to the hull. Or maybe I am misunderstanding or you are answering someone elses question.

On a related note, has anyone put a 'wear strip' on the bottom of thier hulls? I notices I have already scraped some of the new gelcoat of of the hull bottoms and was thinking that might be a good preventative measure for the future.

Wolfman wrote:
On a related note, has anyone put a 'wear strip' on the bottom of thier hulls?.

Yes, this is done regularly, especially for boats that do alot of beach landings. There is a California sailor that did "wear strip" in carbon. Not really needed unless you have a free supply of carbon, otherwise glass would work fine.

RE: On a related note, has anyone put a 'wear strip' on the bottom of thier hulls?.

I use Marinetex. 3-4 inch thin strip applied with a taping knife along the entire hull length and sanded smooth. (I just recently learned you can smooth it wearing surgical gloves and dish soap if you want to avoid the sanding.

Stuff wears like iron and the sand contact will further smooth it. I touch it up every spring. My solution elicits shock and horror from Nacra racers but it was a matter of preserving the bottom against the baby head rocks, pebbles and course glacial sand of Lake Mi. (Works great on daggers and rudders too!)

Thanks for that advice! I think I will have to get some marinetex for the fall. Does anyone have pics of applying this stuff? Is it a fairly easy process?

Does anyone else have comments on the boinginess of the hulls when walking on them after a capsize? Or keeping rivets from pulling out of the hulls?

Easy to do. Because it is catalyzed you can smooth it with a gloved finger and dish soap. (Might be the way to go because it is a beast to sand.) You mix it and you have about 15 minutes to apply it with a putty or taping knife. Also you clean the area with rubbing alchohol or benzine. The instructions are pretty explicit. Best if you could leave your cat upside down for a couple of days to cure.

Unless you walk the hulls with metal spikes in your sailing boots you can't hurt them. They are however very very vulnerable to sharp rocks and sharp objects.

My 91 5.8na has foamcore construction and no flex.

PS: Nacra's were not made for use in surf conditions. I generally do not go out if we have breakers on the beach. (a: its really tough to manage the 5.8 in surf; b: I don't want to hit the beach at surf velocity.) I have gotten really good at dumping power regardless of wind and kissing up to the shore.

we surf launch every weekend and havent had any problems. I dont think hobies get out through the surf and back any better than nacra's ?

I power down, travel out, uncleat the main, and turn up into the wind right before i hit the beach and roll it in on my cattrax. Beach launching takes a little practice but is alot more fun to me than the other options. Nothing wrong with a little excitement! Here in TX our waves are petty small. gt300.com has some great beach launch photo's!

I beg to differ. Dealing with Dagger boards in the surf stinks plus the Nacra hull volume makes the darned things bob like corks. Hobies were made for the surf. They are tough and cut through the waves. The asymetric hulls dig in right away and give you great control. If I was going to launch in a place where there was a lot of surf, I'd go with a 16. I'm also talking about big short wavelength breakers that break right on the beach and can stand a cat straight up on her stern. Fortunately we don't have them very often.

Larry is right about the stand up on stern thing. I flipped bow over stern on Lake Michigan. Luckily the only damage was a broken daggerboard and bruised pride.

Wolfman wrote:
Does anyone else have comments on the boinginess of the hulls

Unless you weigh a bunch I would be concerned that there is something wrong. I'm #225 and do not have these issues, nor have I seen them or experience them on numerous platforms.

BTW, the 5.8 as well as the N20 are fantastic platforms in the surf, as are all beachcats, IMO.

Well that's what is great about online forums...Everybody has their opinions!
Ive launched Hobie16's in surf and Nacra's in surf and cant really tell a big difference. As for the daggers...Dont fiddle with them in the surf...Pull them up pre sand bar coming in and put them down post sandbar going out. No big deal.

In surf we place all of our weight on the front crossbar or even slightly up onto the bow's and have never had any huge problems. We have pointed her straight up in the air before....Normally in these conditions it doesnt matter what your on...Your bows are gonna go up! SURF'S UP!!!!

Timing the sets, good communication between skipper and crew, and a little luck will all help you surf launch your cat whether its a Hobie or a Nacra. If any of these key elements are missing it doesnt matter what kind of boat your on....Your gonna have a hard time. The key for us is really the communication and the crew letting me know when a big one is coming so we can prepare for it or turn into it.

The gt300 and the Tybee500 are both beach launch races and the Nacra's and Tigers both seem to do well.

I suspect you are working with surf/wind conditions where you can pick up some momentum before hitting the waves and a fairly board friendly drop off. I've had plenty of success sailing 16's through those conditions. What we are describing is having to shove off the beach, running like a bobsled team, right into a wave with no power, jump forward and pray you get your rudders/boards down and underway before you get knocked back or sideways. It sucks. (I dislocated my shoulder one afternoon trying to do this) Usually we have a NE coming straight on which creates these conditions on my beach. Hobies handle this much better than Nacra's. Those are the days I wish I had a 16 or my old T14.

No, not board friendly. It is simply learning to handle the rig. My 5.8 is set up specifically to deal with difficult surf. My side loaders for the daggers function flawlessly, so they will stay exactly where I put them. I also have the boards marked in 4" increments for depth. My rudders have oversized bungees that hold them up way above horizontal, and allow me to put them where they are needed.

A couple of challenges are to learn to sail the boarded boat without your rudders and boards. You should be able to turn without the foils and use only the main and jib to steer, second learn to back up your boat. Learning these skills will make the difficult surf, waves, and long shallow water a manageable experience. Time and experience will prevail, but you must learn to master your rig.

To add, there are certain beach, shore conditions you must evaluate and make the decision to not go, even when on the H16.

TurboCat,
I agree and really appreciate your comments on good crew communication. It is usually when successfully getting through the breakers that skipper and crew agree that it is time to pop a beer. 🙂

That last statement says it all!

Check on the loaders/markings but I do need to replace the rudder bungees with something more robust. This looks like a pain as I had a good look at them when I replaced my ropes and pivmatics this year. And yes you are right, Lake Mi does not have tides and sand bars which makes the skils you describe essential. Something to practice.

Problem on the worst of these days is getting 45 degrees on the wind after driving straight out into the surf. I also need to grind out the filler in the trunk bottoms that the previous racer owner put there to make the boat "faster". It takes too long to drop the boards as first they must flush the beach debris. Cost me a late start in a club race this Saturday extracting pebbles that got wedged when my crew put the boards down too quickly.

lately our winds have been coming straight onto shore. I have a different strategy than most in Surf. I like as much boat speed as possible. I feel powering up quickly is essential to breaking the surf. I would rather punch a wave at a bad angle than going slow and turning into irons going over a wave. I have had the best luck with worrying more about momentum than my angle of attack. I leave my rudders down slightly, Fight the weather helm and build as much speed as possible. If you have enough speed u can generally punch the wave and come out victorious! The key (for me) is not pointing up high enough that you get stuck in irons in the surf. Even if its a big one i still try to maintain some speed and not turn totally into it. Im not gonna let it hit me broadside though...Theres a fine line there that can not be easily described on the internet.

Ill leave the surf launch debate to you guys.....Im going home to work on the boat. I will take some pics!

I love the Surf! Am i crazy? yes i am.

Excellent discussion guys. I'm learning a lot.

Just to follow up on Wolfman's concerns about what he's stepping on when righting the boat, I wanted to ask if any of you can confirm that you can or do stand on the daggers in order to get more righting moment. I was assured by someone who should know that the daggerboards are engineered to take a lot of load (he used the weight of the boat as an example) and that as a consequence it is perfectly okay for even a 200+ guy to get out on those things when getting the boat back up. He added that of course one wouldn't want to be jumping up and down.

Anybody do this?

You can but I would not. Replacements are VERY expensive.

I have in the past, but as Lawrencer said they are expensive so i opted for a murrays waterbag for a fraction of the cost of a new dagger.

Im really leaving now 😀

Have a good one, will post pics tonight or in the morning 🙂

edited by: TurboCat, Jul 13, 2009 - 10:40 PM

RLC, I righted my cat by myself last weekend and didn't need to stand on the daggerboards. My mast is really well sealed but I was still surprised at how easy it was to right with a bungee attached to the dolphin striker and thrown over the top hull. I sealed everything (mast top casting and all rivet holes) using a latex tub sealant. Probably should have used a marine caulk but this seems to have worked (of course the mast may have been well sealed before).

The other thing that was told to me (but I haven't tried) was to make a ghetto mast float you can just attach a tetherball (if you have any idea what that is, it's like a basketball with an eyelet on it) to the top plate on the sail. Apparently it bangs around a bit but doesn't damage anything and keeps your mast from sinking (and looks moderately less silly than a hobie bob). I imagine an inflatable dock bumper would work just as well.

As far as hull flex, from what I am understanding from the posts and some of my own research is that Nacras that are pre 1985 are fibreglass only construction and tend to flex on the sides (not the top of the hull). Post 1985 boats are foam sandwich, are much stiffer and don't flex. So I am surmizing that as long as I don't hear any crunching and don't find any localized soft spots I'm likely OK.

Also since I live about as far away from any ocean as you can get I don't have to deal with surf (Winnipeg, Canada). Thank goodness, it sounds like a real pain. 🙂

One other question I have. I went out for about 5 hours yesterday and came back and emptied what looked like about 2 gallons of water from each hull (probably less). I know that most cats tend to take on some water as they get older. Is this an abnormally large amount? Should I leak test and seal them right now or can I wait until I take the boat apart in the fall?

D.

My suggestion would be to go ahead and fix your problem. Use a air supply with little pressure through the plug holes and soapy water. A blow dryer on cool works well.
2 gallons of water is too much over that period of time. I have seen worse but if it were my boat i would go ahead and test it with the soapy water. Leak testing doesnt really take al that long to do.

When i sealed my mast i did the following: Drilled out all rivets, removed head, placed a cooler lid on top of my mast and pressed down on it leaving a mark on the cooler, cut out this shape, apply generous amounts of silicone to the sides and slide down into mast about 1 foot, do the same with a second piece of foam, apply more silicone to sides where it makes contact with mast. Now you have a internal hobie bob. Even if your mast develops a leak in the head the mast is internally sealed and can only take on 1 foot of water (or whatever depth u set the foam). I used a silicone from the autoparts store that looks like a tube of caulk which made it easy to get down in the mast for the final seal.

It's likely leaking from where the barberhauler eyelets are pulling out and maybe the ports (the hulls themselves were recently filled, sanded and gelcoated). I just find it hard to believe that such a small crack on top of the hulls could leak that much (but I've often been wrong). I'm hoping it wasn't a shoddy fibreglassing job or something more difficult to deal with (which is why I was worried about the give in the hulls).

What would you use to seal the holes and cracks? Marine Silicone, Sika-flex, MarineTex or another type of epoxy?

i seal around the ports, plugs, etc with 3M 5200.

I would try the soap and see if its obvious. The dagger trunks have been known to leak so dont forget to check in there.

I have had my decks on the boat leak before but if you just got gel coated i doubt its the decks.

Hey Everyone, Thanks for all your advice. I sealed all the rivets and where the barberhauler eye straps pulled out with 3M 5200. I also replaced the drain plugs (the old ones were pretty decrepit). Went out yesterday (without barberhaulers) for 4 hours and the hulls were almost bone dry! Now I just have to fix the barberhauler system. I still like Turbocats solution and will probably adopt that one. Easier, quicker and less messy than doing the fibreglass work and though bolting required to put them back where they were.

Regards,
Dave

Great news Dave! Leaking boats are no fun and can limit your ability to sail long distances. Now that its not leaking you can focus on sailing and not sinking!

Yeah, I'm finding this boat is a DREAM compared to our old Hobie 16. Easy to rig, no pitchpoling, lots of bouyancy and it really cooks on a reach!

Here's a simple and cheap thing to help the rudders...Increase the purchase for around $10-15. Two blocks and some line. This really helped me pull the rudders nice and tight. I have since added balls to the ends. I tried t handle but the leeward would flap around too much.

If you have to replace your pivmatic's buy the ones with the metal cleat or retrofit.

If you do this it will take twice as much force to trip the pivmatic.