hi all,
it seems that nacra licensed an australian company to built nacras there

i was wondering if anyone knew what differences there were between australian and american built versions of the same boat. ie 5.2 and 5.8

eg i see australian nacra 5.2 owners talking about 6 inspection ports. my usa? built 5.2 only has 4 ports and i've been wondering if i should put 2 more ports in the now blind compartments forward of the main beam just to check stringer condition (and prevent an airborne disintegration)

eric e

have been wanting to ask this question on the australian catsailor.net forum but even though i've been signed up for 3 weeks i still get a message saying i can't post.....how long does it take to get cleared?

catsailor.net haven't cleared me after registering about a year ago. I quit trying after about 2 months! It is a strange system because I saw ppl who registered after me posting on that forum.

And the birth of a new sailing term. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

I have been worried about the same thing. After closer inspection I noticed that around one of my bulkheads there are a few cracks so I plan to pull the decks off this winter.

Word is I can order new top decks from Nacra if I destroy one while removing it, is that true?

Build your own, you'll need the skills to fix the bulkhead, and put the deck back on, so why not just make the part you need.

Get the west system instruction booklets and start reading them, before you know it you'll be posting pictures of your repair and your improved new boat. The deck is mostly flat and a very easy project.

Bill

I have seen that people have removed the decks and put them back on without destroying them but I am worried that I might tear them up.

But I do like the idea of building my own decks, looks like i need to find those west system instruction books.

now that would be a very california look, a "woodie" nacra with decks made of 1/4 ply with a layer of glass cloth on each side and clear resin. you could glass the cloth on both sides and let it cure before mounting the panels. i imagine you would want to have the base with lots of resin, so you had a strong, waterproof layer, but the tops with just enough resin to soak into the cloth but still leave the weave raised for grip.

eric e

I like it <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

email the brisbane catamaran centre who are the nacra dealers/ builders or alternatively wait while I put a question to aussie nacra sailors on catsailor for you.

EXCELLENT idea Qb2

have just fired this off to them, if i hear nothing in a few weeks and still can't post to catsailor.net i'll pm you ask if you can ask them there for me:-)

"hi,
i'm an australian currently living in japan and a couple of years ago i took up lake sailing in a 13foot yamaha dingy

a few weeks ago i bought an american built 1982 nacra 5.2 and am currently trying to learn as much as i can about how to sail it and look after it

the best forums i've found for info have been the usa's catsailor.com and the aussie forums at catsailor.net

recently on catsailor.com a restored usa built 5.2 suffered catastrophic hull failure, possibly due to stringer de-lamination in the blind forward compartments

http://www.catsailor.com/forums/showflat...true#Post118887

and i see stories on catsailor.net about an aussie built 5.8 suffering disintergrating bulkheads, the bulkheads look very different to those in my 5.2....

i understand that these are old boats of uncertain history and not reflective on the majority of nacras out there but i'm wondering if it's worth cutting 2 more inspection ports into the forward compartments of my boat, just forward of the main beam, to check the other side of the bulkheads and the stringers

i would welcome any comments you could make

and if possible it would be great to know what differences there are between aussie and usa 5.2s built in 1985

eric e

I would carefully consider where you put inspection ports forward of the main beam if your boat has a forestay bridle.

Forward of the main beam, a cats hull acts like a cantilevered beam. The deck acts like the web of the beam and is subjected to shearing forces (as opposed to tension (outboard side) or compression (inboard side)). Cutting large holes in the deck without careful positioning or reinforcing probably isn't a good idea. The shear force in the deck is the same from the bridle attachment to the main beam. Plastic ports don't have great structural properties.

If it has a forestay foil like some of the nacras, it is less of a problem in my opinion. This is because the deck is then predominantly subjected to compressive loads which the gunwales (and their extra connection laminate) should be able to withstand.

Having said this, I don't know much about a nacras structural properties.

From a purely structural point of view, a better place would be on the outboard or inboard side of the hull, much more effective area of structure remaining once the cut is made.

Looking at the nacra photos with the decks off, if glued back on well, they will be structurally effective.

Sorry for the rant, I've recently destroyed a hull, same way as airborne, and would hate to see someone put a port in such a dubious place without knowing the risks.

I agree with ncik. I would never put a port in the hull foward of the front beam. That is the area that takes the most load on the catamaran. This is just my thoughts. I don't think I would put them on the side of the hulls either. You might try drilling a hole in the center of the foward bulkhead and find a bore scope or something the will let you look through the bulk head and on both sides of the hull.

airborne

Airborne I think your little crack up has every 5.2 owner in the world worried about their boat. I will be taking the decks off mine this winter to find out what is going on inside.

thanks for the input guys, i figure there's no point in reinventing the wheel so i'll just let gree pull his boat to bits first before i do anything rash to my boat like reach for a powertool. as he has a nacra and a hobie it seems only fair!

i only mentioned the ports as some aussie owners talk about having 6 ports on their hulls...

have attached my contribution, a poorly taken shot of a 5.2 full fiberglass forward bulkhead that looks nothing like the cracking 5.8 bulkheads

Thanks erice, My boat has been raced hard before I had her and I have not been gentle at all.

I will take tons of pictures while I rip my boat apart so you know what it looks like.

I guess if I had another 5.2 I would check it out in the winter too.

airborne

you should maybe consider putting in sub decks in to minimize the towin of the bows. it know it made tornados stronger when they started adding them.

I put your question to catsailor.net but despite 3 replies probably didn't get the answer you wanted, and posed more questions on who designed what! cheers, QB2

Quote 1: "I can't confirm if there were any differences between a USA built and Aussie built 5.2, but I can conform that my 5.2 only has four inspection openings, not six.

2: Inspection ports are often added to effect repairs...check beams and dagger casings.


3a: My first 5.2 # 1607, mid 70's had two ports in each hull,one just behind front beam,one midway rear beam and transom.
As stated in other posts, people do put ports in to suit repairs etc, but the manufacturer really should be consulted beforehand.
aah, aah, Happy Memories,
pete

3b: The American 5.2 had only "one(forward hand) on trapeze", the Australian had "two on the wire", I believe the Americans may have changed to the Aussie system later.
As always the aussie built boats were the best.(in my opinion).5.8,-,5.2,-,5.0,-,4.5.
The boats that Ross designed, here in Brisbane, were copied by the US, (Sirocco, 4.5, 14sq,16sq,Inter17)
pete

thanks for that Qb2

it does answer a few questions i had

1. it seems 6 ports were not a factory thing anywhere, extra ports will probably have been added by owners. haven't heard of any of those boats breaking yet, good, but as has been said probably best not to go cutting good deck without very good reason

2. some reports on 5.2's i've seen said that the pre-85 solid glass boats where lighter than the foam cored boats. other reports have said heavier. presumably if there were 2 versions of foam cored boats made this might explain that

3. when rigging the boat i noticed that 1 of my stays has a trap wire swagged on to it at the top but on the other side the trap wire is a separate line, the boat came with a spare stay. possibly the swagged stay is oem from the early days when the 5.2 only had 1 on the trap, like the tornado, but the other side was replaced and the stays came as a pair

nothing really important but i do like to learn as much as i can about the history of the old things i buy as understanding them better helps to keep them going longer

eric e