I have suffered a failure of one of my 6.0 NA wing seats. It failed right at the point of which the seat comes out of the crossbar. I had it repaired. Alum welder inserted 1"x3" alum roundstock at the point of failure and rewelded it. It looked good, but failed again in the same place.

Looking forward, after getting it repaired I'd like to further reinforce it. I think adding 4 additional tubes one at each corner from the seat to the cross bar is my best course of action. Can anyone confirm it would be suitable to drill the cross bars for pinning?

Any thoughts on this subject matter would be appreciated.

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Nacra 6.0 NA
Ogden Dunes, IN
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Please add some pics as a reference and i will comment and show examples of what the fabricator did to minimize these issues on my wings

I don’t have a picture of the failure. Plus what’s done is done. The fabricator already has the wing. Question is will adding another support from the seat to the cross bar be ok? Picture of wings for reference.



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Nacra 6.0 NA
Ogden Dunes, IN
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sorry - i am dense
where is the break? a b or c?



I think i understand- you want to frame out the entire seat area again (4 new tubes) and add another "arm" that is bolted to your beam (aka crossbar)?

is that what you are suggesting?



Edited by MN3 on Aug 01, 2019 - 03:05 PM.

Sorry for the confusion and thanks for the help in advance. The break is at 'A'. and im looking to add a tube from 'B' to my brothers big toe on that cross bar I mean. That would be one brace and I would add 3 more at the other 3 mounts. 2 per side...

Make sense?

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Nacra 6.0 NA
Ogden Dunes, IN
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yes makes sense

I have photoshoped in an alum tube from B to A so i can better picture what your saying and how it looks




yes i think this would help reduce the stress/wear/failure at that bend in "a" in the future (but how will you mount it? - this needs to be a very secure and reinforced connection or you will wear on the beam and worm holes into it )

on my wings , i had alum compression tubes welded into my beam where the bolt goes through (this is where my wings pivot up and in for transport) drilled 1 size bigger than the bolt, then i ordered delrin inserts/bushings/sleeves from mcmaster car. these isolate the bolt so there is no wear and no rust possible.



https://www.mcmaster.com/bushings (ps i am not 100% certain this is the actual bushing i used but looks like it)

A brace from the top of the wing to the crossbar would certainly stiffen up the wing, but it’s going to be a bit cumbersome and make installing/removing the wings less convenient. Doesn’t seem like you have too many options at this point, unless your fabricator can make an entire replacement wing tube section from a thicker wall tube.

sm

Your wings look stout! I like the hiking strap. That's a good thought on wallowing out the crossbeam. Ill try and come up with something. As for the cumbersomeness, I'm not too worried about that. They're already pretty difficult to install. Pinning or bolting the extra brace will be the easy part. Thanks for the help guys. I'll report back with the results.

Kevin

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Nacra 6.0 NA
Ogden Dunes, IN
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I’m thinking 1/8” wire rope on a turn buckle that you would tension on installation. From b or c to cross beam.

Solid strut would get loose as soon as the pins “wallered” out a little and it be tough to tension them initially anyway.

That is pretty small diameter tubing. I'd be tempted to have new ones made of stainless. The wing tubes on my hobie are 2 inch od.

beavertailskiff

I’m thinking 1/8” wire rope on a turn buckle that you would tension on installation. From b or c to cross beam.

I was thinking about some vecrtran - but not sure where on the beam to secure it

As a thought... You can get smaller diameter (e.g. 2") stainless exhaust pipe and have it mandrel bent at a muffler shop... I think you can even get it in 304 instead of 18-8 stainless so less apt to rust. Only thing is it's thin, so you need at least a 2" diameter to make up for that. But, it's weldable, bendable and you can polish it, etc. Oh, and you can get pre-bent sections that have flared ends, so it would fit together and just need to be MIG welded - easy to do loops, etc.

Just an idea.

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Chuck C
NACRA 500 Mk2
Hobie 21se (sold)
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5' of 2" 304 stainless tube = 54 lbs = 108lbs for both arms = 216lbs for port and stbd

dat's a lotta weight just for seat arms

this throws off your CE a fair amount - esp since ALL the weight is aft of CE

Alum (1100) round tube w .5" thickness = 14 lbs

My wings weigh about 25lbs each - with covers and hiking strap and they put weight in the wrong spot as far as i am concerned - they are nice to have but have been in my garage for over 2 years now

https://www.twmetals.com/…sources/calculators.html



Edited by MN3 on Aug 02, 2019 - 03:45 PM.

Never mind - man! that stainless exhaust pipe is expensive! Cute idea, but at $8/foot...

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Chuck C
NACRA 500 Mk2
Hobie 21se (sold)
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another idea for you:
look at my wing on the beam end


fabricator designed this to be a beam 1/2 cover (cup) that is pinned into place
meaning: when the wings are folded down from transport position: the 1/2 cover fits over the top 1/2 (give or take) of the beam (very good fit). i then put a simple pin in it (a 7"ish ss pin with an eye on one side) that gets secured with a little bungee loop (that is through the eye)

so you could weld or even bolt (so it can swing) an arm from "B" that the other side ("a") "cups" your beam.
a small hole drilled horizontally through this cup and your beam can be bolted (loosely) or pinned as mine is \

this would give you the needed support on the arm's "a" point" (and add less flex in the entire seat setup)
my setup the weigh pushes the cup onto the beam so there is little or no wear at this location
your setup would have lots of "pull" on it at the bolt/pin so i would still consider using a sleeve like i show above to spread out loads (rust isn't really an issue since most don't leave the wings out all the time unless stored outside mast up)



Edited by MN3 on Aug 02, 2019 - 04:17 PM.

Well it isn't elegant, but it should help. Plus I didn't have to drill any holes in the boat which I like.

1/8" stainless cable jacketed. With extra protection around cross bar.



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Nacra 6.0 NA
Ogden Dunes, IN
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looks good except that hook
it will not be your friend if you stuff your boat and get an arm or leg (or face) in there

i would use line to lash it vs hardware, but i like where you went with this

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looks good except that hook

I actually crimped that hook. so its captive around the cable. Just need to loosen turnbuckle all the way to remove.

I thought about using some Dyneema or something instead, but I've never worked with it. Next set of trapeze wires will be synthetic for sure. For education's sake.

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Nacra 6.0 NA
Ogden Dunes, IN
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304 instead of 18-8 stainless so less apt to rust.

Isn’t 304 and 18-8 basically 2 names for the same thing?

If you’re going to go this route, why not just run the cable down from the mast tang (i.e. attach a trap wire to the front of the wing). Doing so would provide reinforcement that is much better aligned with the applied load (gravity => down).

jalex

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304 instead of 18-8 stainless so less apt to rust.

Isn’t 304 and 18-8 basically 2 names for the same thing?

That is my understanding as well, the two are more or less synonymous. If you want less rust, use 316.

sm



Edited by Dogboy on Aug 14, 2019 - 07:20 PM.

I had thought about that. It would certainly be stronger. I was worried about compensating for mast bend, tightening it enough that it would take weight, but not take weight off side shroud. They should be stronger than oem now and that's should do it.

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Nacra 6.0 NA
Ogden Dunes, IN
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