How is it that everyone talks about early boats having bendy masts and some later ones having stiffer ones, (the 80-90s boats) but when I email NACRA they say they only ever had 1 extrusion for all the boats of that era and that the new extrusion is only new because they lost the tooling for the old one and that the new extrusion is made to be as similar to the old one as they could..

According to them all the masts made for the 5.2, 5.5, 5.8 etc were all the same.

I don't exactly have a fleet of different NACRAs to go shake the masts on. Anyone have some real world experience on this other than the internet rumor mill?



Edited by tamumpower1 on May 15, 2017 - 04:49 PM.

Hi Matt,

It is common knowledge in sailing that everything is stiffer and stronger when it is newer. But, it often generates a ton of discussion whenever there is any sort of change by the manufacturer.

One person may have a lightly used older version of whatever and achieve as good or even better performance in the short term against whatever the new thing is. But sometimes manufacturers "upgrades" are for better longevity at a minor expense of performance.

There are few cases where older is better in sailing and none I can think of over a significant amount of time.

Do you know of any?

Brad in Jax



Edited by bradinjax on May 15, 2017 - 02:00 AM.

New masts, specially the wing masts can be pretty bendy and "soft". I have never heard of an older Nacra mast considered stiffer or softer.

Whats at play here is probably just someones seat of the pants observations taken as fact and it continues online.

--
Greenville SC

Offering sails and other go fast parts for A-class catamarans
--

No direct experience with Nacra masts on this topic, but have experienced a difference with other masts of similar age to each other and built "identically".
Had two h16s of same age (1 year apart) and each had distinctly different bend characteristics.
I chocked it up to differences in the manufacturing process while extruded. Speed of extrusion, and possible differences in aluminum material content.

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Several Sunfish and Sunfish clones
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i don't know about different nacra masts, but i certainly know there are large differences of rigidity between brands - i.e. hobie vs mystere

MN3

i don't know about different nacra masts, but i certainly know there are large differences of rigidity between brands - i.e. hobie vs mystere

Yea my H18 masts are like viagra ragers compared to the 90 year old limp noodle that is my nacra mast.

how long have you had the 18square?
ever use it?

MN3

how long have you had the 18square?
ever use it?

2 weeks. Now that the mug race is over I'm in the middle of a full strip/repaint/rebuild of the whole thing. It didn't need it at all, boat is dang near 95%, but I have to be able to trust every bolt and rivet in the thing so the only way to do that is to rebuild it myself. That way if I have to throw it into mug race conditions I know it wont fall apart on me.

cool
buy it locally?
paint? not gelcoat?
what type?

MN3

cool
buy it locally?
paint? not gelcoat?
what type?

Nah I had it delivered from Houston. The previous owner was a big racer so had stripped the gelcoat and done a coat of imron on it to save 10-15lbs. But that was a long time ago and the bottom could use some paint so I'm just gonna sand it down a reasonable amount and spray a coat or 2 of enamel. I have a hvlp setup so can get a pretty even coat. I've got a lime green color I mixed in the garage last night that's looking pretty fun. I think I'll go with that.

No point in going with awlcraft or anything like that around here. I'd have that sanded off in one season lol. To do gelcoat on an entire hull would be difficult to avoid sagging and since it already doesn't have any anyway I don't see the point. I can spray touch up at will anyway. Might even do a thin layer of resin just on the bottom for sand resistance. That being said the boat is pretty dang fragile. 375lbs all up. I might pull it up on an island a little but I can't abuse it like the H18.

I just want some photos of me trapped out flying a hull 11 feet in the air, then I can retire it...

Quote

No point in going with awlcraft or anything like that around here.

why do you say that? the Awlgrip on my 6.0 is still perfect (sans the areas where i have scrapped it off with poor handling / rubbing / demasting

The one thing i do not like about my painted cat is: it acts like an etch-a-sketch and every scratch is white, on a grey boat... sticks out a lot (tons to me).

PS i hope you have the correct gear for sanding imron - pretty nasty stuff

I'm right with you. It wouldn't be horrible, I just feel better beach sanding off a 40 buck paint job the first season than stepping up to the expensive stuff right out the gate. Pretty much my whole life is fixing/rebuilding stuff so it won't break my heart if I have to sand it off and use something higher quality next year.

Yea I don't plan to sand it too much really. I do have some breathing gear. I'm going to sorta treat it like my primer to help level the hulls. I just feel bad not taking a little off in the hopes of saving a few pounds on my race boat lol.

Why are you beach launching and landing your 18 square? Its not a hobie cat, the fiberglass on the bottom is quite thin and you'll wear through this in no time. Use a quality paint and beach wheels.

I have beach wheels for it. The dude made them out of ATV wheels. They are the most beast beach wheels you've ever seen lol. But we stop on islands around here. Just lifting and setting the bows on the edge of the sand. It will be fine for that. That's why I'm gonna put a little extra paint, maybe some resin protection down there. I didn't mean I'm gonna come full speed kamikazi at the beach.

I know some people that have had the enamel paints last quite awhile on fiberglass boats. It's not talked about on the internet as much because most people don't do paint themselves but it's more common than people think. It's what I use on my rudders and it took 2 seasons of shallows to take it off so should be no worries.

Quote

I have beach wheels for it. The dude made them out of ATV wheels. They are the most beast beach wheels you've ever seen lol. But we stop on islands around here. Just lifting and setting the bows on the edge of the sand. It will be fine for that. That's why I'm gonna put a little extra paint, maybe some resin protection down there. I didn't mean I'm gonna come full speed kamikazi at the beach.

Our beach wheels are also atv rim/tires (but i get the feeling yours are a little more monsta atv)
Ron had CF on his hull "floors" didn't last too long
i suggested he get some kevlar down there, put a strip or 2 under the gelcoat - he didn't want to work with kevlar (too hard to cut) lol

I gotta glass up some cradles for them. I got another set with the boat that isn't connected by a bar. It's like an individual pair of wheels for each hull. More useful for setting the boat up I'd figure but still kinda cool. Once I sail it a few times I'll get to work welding up a tilt trailer for around town.



Edited by tamumpower1 on May 15, 2017 - 04:44 PM.

11' beams?

Please call me when your going to the beach so i can be no where's near you on that bridge with 11' wide boat going over that crest

I drove a 10' one on a flat trailer once ... will never again

ha no right now it doesn't trailer flat. Its a take down setup only. That's why I want a tilt trailer for going around town. Should be able to rig one up for like 200 bucks of steel on top of the existing trailer frame.



Once setup it's a thing of beauty though...






Edited by tamumpower1 on May 15, 2017 - 04:58 PM.

Tis a beast!
funny - a boat built for a single sailor but can fit 18

love the traveler track!

Mike Krantz has a killer tilt trailer with gas struts that can be lifted/lowered with one hand... (for his carbon20)
there is a thead somewhere (edit - found it)

https://www.youtube.com/watch?v=9PsAZADGRm0

https://www.catsailor.com…trailer-plans#Post278298



Edited by MN3 on May 15, 2017 - 04:06 PM.

Dang thats pretty sweet. Not sure where to get struts that long. Might be something I mess with for fun.

and yea the previous owner(owned it since 84) is a machinist and actually made the whole setup. The traveler is machined out of a solid piece of aluminum and has little replaceable ball bearings on it. Pretty slick actually. Then he took the old harken car and cut a piece of the old traveler off and used it for the outhaul. It's the most high load outhaul car you've ever seen!

Quote

Dang thats pretty sweet. Not sure where to get struts that long. Might be something I mess with for fun.

if you read the post he tells exactly where he got the struts
he told them the size and weight of his rig and they told him which struts to order

Rocco made a tilt trailer a few years ago - similar idea but no where's as nice an execution
his was built too high off the ground it it was a bear to load and unload - and his struts were not quite enough ... so in the end it was not great - a large part of why he stopped sailing his mystere 6.0 xl

That is a good looking boat. With a modern square top, it would be killer.

Tilt trailers are all a pain in the rear. Need to counterweight the trailer which makes them heavy.

I'd be hesitant to do much to that boat, she looks in fine shape. If you just lift the bows up onto the beach there shouldn't be much wear. Maybe carry a par of throwable PFD's, these make good padding. Kevlar is very abrasion resistant but there are a lot of other issues, a big one is that paint doesn't want to stick to it.

Not sure who you emailed within Nacra, but I didn't hear from you.
I'm guessing that what you heard about being one mast on those boats is right. However, over 40 years some things are bound to change in production.
Also you have to remember the company was purchased in 2007 and we no longer have anyone that was involved with the company prior to 10 years ago. A lot of our information was lost in the great minds of some of our predecessors.
We have a handful of extrusions in our U.S. inventory that we're not even sure what they are.
We're doing our best to support the older boats but it's really quite difficult! There was no internet databases back then that we can still access and most of the paper has been lost.

Quote

Kevlar is very abrasion resistant but there are a lot of other issues, a big one is that paint doesn't want to stick to it.

could be buried under a few layers of gelcoat - correct?

samc99us

That is a good looking boat. With a modern square top, it would be killer.

Tilt trailers are all a pain in the rear. Need to counterweight the trailer which makes them heavy.

I'd be hesitant to do much to that boat, she looks in fine shape. If you just lift the bows up onto the beach there shouldn't be much wear. Maybe carry a par of throwable PFD's, these make good padding. Kevlar is very abrasion resistant but there are a lot of other issues, a big one is that paint doesn't want to stick to it.

Yea I'm with you. I think I'm going to take the easy route for now and just re blast paint on it as needed before getting into exotic materials. I'm pretty good about knowing the shallows here locally and I doubt the hulls will ever get sanded too much. I've already stripped the gelcoat off the boards and rudders and filled them back to new and put a few extra layers of sacrificial glass on the tips for when they eventually carve a little sand.

nacrasailing

Not sure who you emailed within Nacra, but I didn't hear from you.
I'm guessing that what you heard about being one mast on those boats is right. However, over 40 years some things are bound to change in production.
Also you have to remember the company was purchased in 2007 and we no longer have anyone that was involved with the company prior to 10 years ago. A lot of our information was lost in the great minds of some of our predecessors.
We have a handful of extrusions in our U.S. inventory that we're not even sure what they are.
We're doing our best to support the older boats but it's really quite difficult! There was no internet databases back then that we can still access and most of the paper has been lost.

Ah, that would explain the crap shoot on the reliability of old information. I'm not sure who emailed me, I might have saved it, not sure. My only reason for the whole thing was that I for sure have a floppy noodle mast and had hopes of putting my 18' sized spin setup over on it but with the mast the way it is it's mega questionable. To get a stiffer mast I'll probably have to retrofit over something from a modern boat instead of looking for a stiff older era mast and then having to lengthen it for the square. The spin idea is on hold for now. Not really in the mood of doubling the cost of the boat just for a newish mast anyway.

Back during the aluminum Tornado mast days, because of the variance inherit in the extrusions, teams would buy multiple masts (like 10) just to get one that they liked. Even though they all came from the same place, some were stiffer or more flexible than others; they even needed to attach corrector weights to the tip if they came out too light. Granted, those masts were made for a higher performance boat, and likely to a smaller safety margin than a typical consumer boat; therefore the extrusion is probably thinner than what Nacra or Hobie would sell and variations is the extrusion thickness and grain structure of the metal would be more noticeable. I don't have any data to support this, just a hunch.

Also, don't forget that different alloys have different properties and the base metal could have slight variations from job to job. Additionally, as aluminum ages, it's structure and properties change; assuming I remember correctly, it will get harder, but more brittle over time. Another guess would also be variations in the extrusions produced as the tooling ages and wears.

When the tornado design was implemented and people were backyard building them who was the official mast supplier since there wasn't a single OEM making the actual boats? I could put a tornado mast on this boat it would just be a few inches short. Most of the squares ended up with 31-33 footers instead of the stock 30' one. If I was gonna put a different one I'd probably go even taller in case I make a new higher aspect main to play with. Kinda hilarious I can put a different design main/mast etc and not take any score penalty. I'm sure people would love it if I show up with a wing mast that's still 18 square meters to a mixed fleet race haha

Both Marstrom and Sailspar built masts for the Tornado in Aluminum (http://www.aita.asn.au/index.php/tornado-info/tornado-classic/tornado-classic-tuning-guides/15-the-classic-tornado-guide)

If you are series about this, call Matt McDonald @ Falcon Marine, he may still have some blank wing mast extrusions available. Nacra may also be able to sell you an Infusion mast in the 32' range, as they use that extrusion (or something very similar, may be different alloy or internal reinforcements) for refitting Nacra Inter 20's and some of their cruising range. There are some other F18 rigs available (AHPC, Exploder, Cirrus) that would also fit your boat but they are a tiny bit shy of 30'. Then you move into carbon rigs, which are nice, but even a fully kitted aluminum wing mast is going to be $2-$3k, which is the base price of a blank carbon wing mast tube.



Edited by samc99us on May 16, 2017 - 10:57 AM.

I bought the struts from bansbach.com. I told them how much I needed to lift and sent them a diagram of the platform. They spec'd out the struts, and told me exactly where to mount them. I could tilt the F20c with one hand.
I think I paid around $200 for the pair of struts.

Nice link to the Australian site. This one guy on there is my hero with the boat name. I might have to copy that haha.


I guess I'll look out for some wrecked or parted out boats and see if I can get a stick on the cheap. I don't really need it, or at least know I need it yet, until I sail the boat and get a feel for how it handles. I can slap my spin on it since its a little bit smaller than the F18 spins and see how the mast looks in light air and just baby it. Might be ok. I know a guy that won a few national events back in the 80s with the noodle mast and he played around with a spin on it and said it was fine for medium air so we'll see. I'm going to convert it to swept spreaders and prebend so that should help the noodle flop at least a bit.

mikekrantz

I bought the struts from bansbach.com. I told them how much I needed to lift and sent them a diagram of the platform. They spec'd out the struts, and told me exactly where to mount them. I could tilt the F20c with one hand.
I think I paid around $200 for the pair of struts.

Thanks, when I get it built up I'll see what I want to do with it. I might end up using the mast support as a crane arm since I have an extra crank winch and just manually lift the frame up. The shock idea is cooler though.

These guys have pretty "bendy" masts and spins up - besides all the capsizes, collisions, and running into tankers, they do pretty well
https://www.youtube.com/watch?v=fFYGJ6ox6DI

MN3, totally different load cases and rigs. Those 18' skiffs mostly have carbon rigs in the air which can take enormous deflections before failure. In either case, keep the mainsheet on and you should be OKAY, the stiffer rigs I mentioned would probably work fine with 100% masthead spinnakers and enough mainsheet.

Quote

totally different load cases and rigs

Oh i know - i was just being cheeky.

i actually have RonStan Skiff race VHF (where i think this video is from)
pretty wild watching those masts curl and flex

Yes, there are differences. It comes down to different ways of depowering the rig.

If you have a 'bendy' mast, you over rotate the mast in order to induce camber on the minor axis, and also creates drag/turbulence in the forward part of the sail.

Stiffer masts use prebend tuning, which combines with extra downhaul purchase and bends the mast on the major axis, with less drag.

The sails are cut different for each approach

IIRC, wither White or Fragale discuss the different modes in their books.

I can state from personal experience that older NACRA Squares had bendy masts with little, perpendicular spreaders and the upgrade was to either install swept spreaders or get the stiffer mast which usually had swept spreaders installed.

Jay
Ex-1981, -82 and custom Squares
Now cruising in my old Catana

Yea so the previous owner who got second at nationals in 87 with the boat says he always ran the stock perpendicular spreaders and pretty loose diamonds. Can touch them to the mast about 18" up.

Then I talk to the guy who won nationals most of the time in the late 80s and he says to go prebend for sure on the bendy mast. I'm gonna try it both ways and check the sail shape. The diamonds attach to the front of the mast up top so there is essentially some spreader rake built in to the setup already and since the previous owner has a 12:1 downhaul on the thing he's already depowering the rig just like a prebend setup anyway. I think with the downhaul I should easily get the mast to bend on the primary axis enough to work given the flexibility of it.

Question is which spreaders should I use. I could use a H18 set and just buy some longer aluminum round bar. Just from looking I think the square has slightly wider arms. Some other boats have a turnbuckle adjustable type which I like. I could probably weld a setup that would use that but not sure if I need that fine of adjustment really.



Edited by tamumpower1 on May 17, 2017 - 12:57 PM.

Tip:
Pay attention to anything Jay says about 18 Squares.



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Thank you, Damon. Hope you're doing well!


FYI

"TUNING THE NACRA EIGHTEEN SQUARE METER

John Brink - 1980 Class Secretary

The NACRA 18 Square Meter is one of the fastest sailboats in the world. However, it is very sensitive to sail and rig adjustments. While there is no guarantee that you will have the fastest NACRA 18 Square Meter on the water, if you set your boat up as follows, you will have a good starting point for further adjustments and your boat will be very pleasant to race.

Believe it or not, the best starting place is at the top of the mast. The NACRA 18 Square Meter is set up so that, if you wish, you may convert to an internal halyard by adding a sheave in the after side of the section near the top. Consequently, the geometry of the rig is based on the premise that the sail doesn’t go all the way to the top of the mast section. Make sure that when your halyard lock is engaged, the sail is a few inches shy of being fully hoisted. If the sail goes up all the way, the boom will be too short.

Now, to adjust the rest of the battens. The theory behind modern (1980) sail batten combination is to use relatively flexible battens and tie them in without much tension. Because the battens are flexible, the sail will take a nice shape in light air without much tension, and when the breeze comes up the sail will flatten itself as you sheet harder and as the wind blows the leech open. If you tie the NACRA 18 Square Meter battens too tight, the sail will be hopelessly full.

Let’s go back up to the top again. The three upper battens should be very loosely tied, perhaps not even quite taking the slack out of the line. The fourth batten down should be slightly tighter, perhaps just barely taking the slack out of the line but no tighter than that. With the fifth batten and on down, tighten the lines just enough to take out most of the vertical wrinkles along the batten pockets. However, sometimes even this may be too tight. Loose is better than tight!

Next, adjust the diamond wires until you can touch them both against the mast about three feet up from the lower diamond tangs. This is a good starting point. There is some give and take between the tension on the lower battens and on the diamond wires. The diamonds can be looser with tighter lower battens. Finding just the right combination is a matter of trial and error.

Now let’s rake the mast back to where the sail is sheeted as hard as you ever want it and with the sheet blocks almost together. Set the shrouds up with plenty of tension so that the mast won’t jump around when going through the waves. The shrouds will stretch some when new, so you might as well sail the boat hard a few times before you get too concerned with rake adjustments.

Another adjustment that is critical to both good handling and speed is rudder alignment. It helps to bend each tiller arm inboard about six inches. Whether you do this or not, you should check to make sure you have the rudders set with a slight amount of toe-in. That is, the leading edge of the rudders should be slightly closer together than the trailing edges. If the reverse is the case, besides slowing the boat, they will make the boat difficult to steer.

Now, to steer it fast. When sailing a sloop, most good sailors will pay very little attention to the main. They sail by the seat of their pants and keep an eye on the jib. With a uni-rig, there is no jib to keep an eye on and many sailors may make the mistake of transferring their attention to the main. If you look at the main, you will inevitably end up sailing too high and going slow. Sail the boat by the seat of your pants and direct your gaze ahead. You don’t have too pinch the boat (sail too high) as the extra width that comes with a NACRA 18 Square Meter allows you to drive off and build speed – perhaps covering more "ground" but at a much faster rate of speed. But, on the same hand – don’t be afraid to sail high to cover an opponent or force them over the line early. The uni-rig NACRA 18 Square Meter will out-point and sail higher and faster than most boats, especially those that are sloop rigged. You can pinch, you can foot, but either way you will be the fastest one out there after some practice and experimenting with different setups."

Did you personally play with mast rake very much for different conditions. I'm assuming the reason the little guide is calling for rake is to help out with the bows givin how hard you can drive the boat. I got the rake position the previous owner used and he said he more or less always ran it in that position but I haven't stepped the mast to see what rake that is.



Edited by tamumpower1 on May 17, 2017 - 08:51 PM.

Be conscious of one thing on spreaders for that mast. The old style round ones from before pre-bend do look crude now BUT since the shroud is not fixed to the spreader tip (seizing wire and tape do not count) it is essential that the spreader tip does not move up and down because if it gets started doing that it will collapse rather than spread. One of the original engineers and Roland had a big fight about that. You do not want to lose that mast. If I were you I would stay with the original spreaders (which were round for a reason) but if you choose not to be careful.

I don't understand what you are saying to do. My current spreaders are indeed one solid piece inserted through the mast with wire holding the diamond to the tip. I guess I can wire the crap out of them?

I'm a bit confused as well. Even the modern spreader arrangements are free to move, and you are correct that seizing wire and tape don't prevent the tip from sliding on the diamond wires. One solution is to put epoxy hardpoints on the diamond wires to stop them from sliding.

What i meant was that the circular cross-section spreaders that go through the mast will not move up and down at the tips. the cross-section makes it hard for them to flex that way so the setup with the shrouds sliding up and down as needed, seized and taped to the tips, is safe. the problem could arise id your get modern spreaders which are 1) not thick walled tubes going through the mast and 2) lacking in vertical cross-section and strength at its base to prevent it for sliding upwards or downwards and collapsing against the mast. I have never seen, only heard. But what I heard was that the first time a mast buckled the guy who raised the issue with Roland said "I told you so." With the set-up you have just keeps the shrouds seized to the end (I always used copper Easter egg dippers for this purpose when i fitted out every year in the spring). Remember you have a bendy mast that has successfully lasted with those spreaders for 40 years. And BTW, no spinnaker, that is another bad move.