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PostPosted: Fri Apr 15, 2022 6:15 am 
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Joined: Sun Apr 26, 2015 3:13 pm
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Scurvy wrote:
mickeymouse wrote:
pro10is wrote:
I'm going to work on my gas strut design next boating season as I feel that it has great potential. I'm going to see if I can come up with a way of installing it on a TI with inexpensive parts and a design that anyone can easily copy.

Gas struts are ubiquitous these days and used for all kinds of engineering solutions. They're readily available in all kinds of sizes and inexpensive.

I was hoping Hobie would do this, but they don't apparently seem to be interested in improving the TI much more lately and have even dropped the AI from production.

I only own an AI these days but still interested see how this idea develops.
I replace the plastic bolts with Stainless & nylock nuts in rough conditions - as well as keep out lines.


You might want to rethink the stainless bolt. It will never shear off, so either the aka will collapse right there where the shear pin boss is welded, or you’ll rip the hull-mounted ball-stud out which = a hole in your hull that turn into a crack.

Regarding the gas struts, unless the whole shebang is stainless steel, they will corrode and eventually catastrophically fail. Simple is always better, so you might want to see my idea about 3 or 4 posts previously — I suggest accomplishing what you are proposing with rope and a strong bungee strap. These items will not rust and any wear is plainly visible, it’s light, it’s cheap, and is available at any hardware store, truck stop, or marina.


The purpose of the plastic shear bolts is to avoid damage to the akas in the event of a collision. However, after owning a TI for over six years and using it extensively in all kinds of heavy-duty situations, I've discovered that the akas are actually quite rugged and can withstand the usual bumps it may encounter with no issues. It would take a significantly heavy blow to damage the akas and in all my experience with the TI, I have yet to encounter such an extreme situation, not to say that it can't happen, but it would be quite unusual in normal operation.

The plastic shear bolts are known to wear and suddenly break on their own without encountering a heavy blow. I've had this happen twice for no apparent reason. Fortunately for me, this was not during a critical time and I was able to repair the problem on the water. However, if a shear bolt broke during a critical time, such as sailing in high winds or rough water, the ama would instantly collapse, and without it, a capsize could easily and quickly occur sending all occupants into the water with the TI in need of righting. That's quite difficult to do in excellent conditions, never mind bad. This is when the plastic shear bolts are stressed a lot, so the likelihood exists and is, in my opinion, a real danger significant enough to potentially cause loss of life. That's obviously very serious.

There are several decent options a conscientious owner can do to try and mitigate this dangerous situation and they've been discussed here at length. They all have their pros and cons. One of those options is simply to replace the plastic shear bolts with stainless bolts. This would not protect the akas any longer, but they really don't need such protection in normal usage, in my opinion, I've now gone several years with stainless bolts and have had zero issues in heavy-duty use. Even if the akas were damaged, they could likely be repaired or replaced. What cannot be replaced is the loss of someone's life. When you compare that with some minor structural damage, or even a total loss of the boat, it pales in comparison. The choice is obvious. I would sacrifice a thousand boats for just one person's life.

So replacing the plastic bolts with stainless ones remains a viable option with its own pros and cons like all the rest. Ropes and bungees can wear, break, stretch, and fail when stressed and impending failure is not always obvious. I've experienced many unexpected rope and bungee failures. There is no perfect solution, any one of them can fail. My primary worry is having an ama collapse during high winds or rough weather, which could likely be catastrophic. I've sailed in such conditions and I know for certain that if I or any of my passengers ended up in turbulent seas with a capsized TI, that could easily be life-threatening. So, for me, relying on a metal bolt to prevent such a situation is better than relying on some ropes or bungees, boat damage be damned.

Concerning the gas struts, these are employed for marine use extensively. Many boats use them for many various purposes. I have one on my Sea-Doo PWC. There are corrosion-resistant models readily available and certified for marine use.

People can choose whatever option they feel works best for them, but the bottom line is that something needs to be done to mitigate the danger.


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PostPosted: Fri Apr 15, 2022 6:40 pm 
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Joined: Wed Nov 26, 2008 4:36 am
Posts: 837
Location: Gippsland Lakes Victoria Australia
Scurvy wrote:
mickeymouse wrote:
pro10is wrote:
I'm going to work on my gas strut design next boating season as I feel that it has great potential. I'm going to see if I can come up with a way of installing it on a TI with inexpensive parts and a design that anyone can easily copy.

Gas struts are ubiquitous these days and used for all kinds of engineering solutions. They're readily available in all kinds of sizes and inexpensive.

I was hoping Hobie would do this, but they don't apparently seem to be interested in improving the TI much more lately and have even dropped the AI from production.

I only own an AI these days but still interested see how this idea develops.
I replace the plastic bolts with Stainless & nylock nuts in rough conditions - as well as keep out lines.


You might want to rethink the stainless bolt. It will never shear off, so either the aka will collapse right there where the shear pin boss is welded, or you’ll rip the hull-mounted ball-stud out which = a hole in your hull that turn into a crack.

Regarding the gas struts, unless the whole shebang is stainless steel, they will corrode and eventually catastrophically fail. Simple is always better, so you might want to see my idea about 3 or 4 posts previously — I suggest accomplishing what you are proposing with rope and a strong bungee strap. These items will not rust and any wear is plainly visible, it’s light, it’s cheap, and is available at any hardware store, truck stop, or marina.

Thanks for response. I like the the zip tie concept. I actually already have several strong reusable ones onboard and very close at hand - but need to work out what's the best size etc.
I have never experienced a capsize in all the years I have owned and used these boats - but I know many who have and was out last week with a mate in his 2022 TI who experienced the shear pin break and capsize. He has sailed all his life and is very experienced at righting upturned sailing boats & was grateful for having experienced it in his new TI because he is now confident that if/when it next happens, he can right the boat unassisted.

_________________
Mickey
2016 AI Hibiscus
purchased NEW Nov 2021 - My 5th
Adventure Island Sailing since 2008


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PostPosted: Fri Apr 15, 2022 8:32 pm 
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Joined: Sun Apr 20, 2008 6:18 am
Posts: 3058
Location: Sarasota,Key West FL
Of course my experience with AMA, and AKA integrity was a little different because all my TI’s were extremely souped up for speed and open ocean, and I sheared off dozens of Nylon shear bolts, ( lol I had to buy them a dozen at a time). One thing I also noticed because we over used our boats pretty much every weekend, is the wear and tear in the bolts themselves, we would use them about a month or so, pull them out to check them and the threads would be worn nearly off or the bolt would be sheered 1/3 of the way thru. Bottom line it’s a good idea to check them regularly.
We didn’t have any fancy system in place for safety lines. We just ran cheap nylon rope from the bow to the end of the front AKA bar, ( which also incorporated our spray skirts). Our spray skirts were heavy duty so people could sit on them, or we could store gear on the spray skirts.
We also had strengthening lines in an X pattern under our tramps, and 4 lines running front to back under the tramps to re-enforces the tramps so we could walk around the tramps with scuba gear on, (over 300 lbs easily). The X lines had the most
Effect being tied around the aka knuckles perminately, the forming an x with the other end wrapped around the aka bar the slipped over the little buttons at the end of the aka’s. We had spectra loops of grey rudder line that we slipped over the buttons, so we could have 4 or 5 things attached to each button. It took maybe an extra 30 second during rigging to put the x lines on. We used 3/16 non stretch paracord 500 lb test. Only ever use black paracord because it’s impervious to the sun, all other colors degrade quickly in the sun.
Make sure you always wrap the cord around the aka before attaching it to the button. The only knot that works with spectra rudder line, (around 300 lbs test), is a cinch knot. We never broke off any buttons in 8 yrs of extreme use.
Prior to incorporating the safety line we did knuckle 2 rear aka bars, and sheered off 1 aka ball on a hull. Knuckling the aka bars means folding them at the aka brace, ( destroying them) and they are not cheap. The force on the brace joint is 3x the force on the AMA.
The measured force to break the sheer bolt is 100 lbs sharp force, ( which is 300 lbs on the nylon bolt. It takes 400 lbs force to fold the aka bar at the brace joint, and around 400 lbs force to break the ball off or rip the hull.
To strengthen my AKA bars I dropped in fiberglass pultrusions into mine then backfilled with rigid polyurethane 2 part foam, for offshore use. But my aka bars were lengthened so I needed that extra strength, ( my TI was almost 13 ft wide to support 600 sq ft of sail area), in open ocean.
Hope some of this helps
FE


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PostPosted: Wed Oct 05, 2022 8:07 pm 
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Joined: Wed Mar 12, 2014 9:02 am
Posts: 30
Since pictures seem to be hard to come by, here's some info and pictures on hardening my AI that I posted on a different forum. It's just a few basic things, most of which are discussed here in this thread.

http://www.norcalkayakanglers.com/index ... c=87733.15


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PostPosted: Thu Oct 06, 2022 3:58 pm 
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Joined: Sun Apr 20, 2008 6:18 am
Posts: 3058
Location: Sarasota,Key West FL
All of us got screwed bigtime by photobucket,,,, I’ll never use them again.


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