This was an awesome; dolphin striker v bar was first failed then the mast plunged into front cross beam and create a crater....it was happened during port reach, 18 kts wind. Anyone had same experience before? Is it worth to replace aluminium V bar with stainless steel?
I had the same thing happen to my P19. I was lucky and saved my beam. Just had to replace the aluminum bar. This is a wear item. That aluminum bends like a tin can and eventually fails at the first bolt. Easy inspection. If you see a crack developing near that first bolt buy a new bar.
There should have been a compression tube in the main beam to absorb the beam - loading from the striker rod (stainless) and the mast base. I saw no evidence in your photos of striker bar (aluminum) failure; therefore, I am presuming the mast/rig pressure caved in the main beam. Were you sailing with a tight or loose rig?
That attachment fitting for the spin strut may have weakened the main beam at a very critical point. We used an aluminum windsurfing mast and snapped it onto the stainless striker rod, secured at the bridle foil. Our tack was internal. Our bag was on the deck - not in a snuffer.
Do you know a former NACRA 5.2 sailor, Nori Osada?
There should have been a compression tube in the main beam to absorb the beam - loading from the striker rod (stainless) and the mast base. I saw no evidence in your photos of striker bar (aluminum) failure; therefore, I am presuming the mast/rig pressure caved in the main beam. Were you sailing with a tight or loose rig?
That attachment fitting for the spin strut may have weakened the main beam at a very critical point. We used an aluminum windsurfing mast and snapped it onto the stainless striker rod, secured at the bridle foil. Our tack was internal. Our bag was on the deck - not in a snuffer.
Do you know a former NACRA 5.2 sailor, Nori Osada?
the first picture shows the dolphin striker snapped where it attaches to the end of the main beam. I think you can also make out the compression tube still on the mast post laying on the trampoline in the second photo.
How many of you guys have aluminum dolphin strikers on your Nacras?
I stand corrected. We have always used aluminum on the earlier NACRA designs. I missed the details in the top photo. The new 20s and F 18s might be using stainless. I'm scratching my head:-)
My guess now is that salt water/corrosion and a loose rig/rod - fit through the main beam via the nuts for compression led to the bar failure. Now, what effect would a stainless bar have on the aluminum main beam other than add weight and electrolysis? Do not forget the four drilled holes for the spin strut.
One half inch of pre - bend in the main beam was good for us in the 5.5 SL "Golden Days." We kept the rig tight and the beer cold.
We even beat NACRA 6.0s on a good day - boat for boat (circa 1993).
I stand corrected. We have always used aluminum on the earlier NACRA designs. I missed the details in the top photo. The new 20s and F 18s might be using stainless. I'm scratching my head:-)
My guess now is that salt water/corrosion and a loose rig/rod - fit through the main beam via the nuts for compression led to the bar failure. Now, what effect would a stainless bar have on the aluminum main beam other than add weight and electrolysis? Do not forget the four drilled holes for the spin strut.
One half inch of pre - bend in the main beam was good for us in the 5.5 SL "Golden Days." We kept the rig tight and the beer cold.
We even beat NACRA 6.0s on a good day - boat for boat (circa 1993).
Keep it Rollin' in 2010, Bert
I've just never seen an aluminum striker bar. Sure, there would be some additional electrolysis but not any more than with the striker post. The stainless has better fatigue resistance - particularly at bends. It would also tend to elongate at mounting holes more than shear like aluminum.
This is classic aluminum part failure at a drilled-hole. Mini cracks develop on both sides of the hole due to flexing. Twink! Does anyone remember the British Overseas Airways Comet airliners of the 1950s? Anodizing does not help.
Dacarls: A-class USA 196, USA 21, H18, H16 "Nothing that's any good works by itself. You got to make the damn thing work"- Thomas Edison
I believe all of the round beams have aluminum striker bars. I have never seen a SS striker bar on the round beams as a factory setup. I ordered a new front beam a couple of years ago for the 5.8, it came with a new aluminum striker bar.
I believe all of the round beams have aluminum striker bars. I have never seen a SS striker bar on the round beams as a factory setup. I ordered a new front beam a couple of years ago for the 5.8, it came with a new aluminum striker bar.
hm. I honestly can't recall what the striker looked like on my old 5.2 or the 6.0NA I had.
Just zoomed in on some pics of my '99 6.0... it had an aluminum striker too. I could have sworn it was stainless but from the pictures it is clear it's aluminum... kinda scary to think about. Haven't seen any failures like this on a N20 or F18 but I did see it happen to a 6.0 or 2.
I noticed there is no teflon washer between the stainless washers and the cross beam. I added some on my N20 to help fight the electrolosis. I dont think Nacra sends them out that way, so if you have one, it's not a bad idea to add them.
Lee
Keyboard sailors are always faster in all conditions.
Finally my buddy was odered the beam,striker v bar from Nacra dealer in Australia. Right now we done a temporary repair,weld,etc. while waiting for original parts. Not sure if the v bar failed becuase of too much load on the mast+after market spi (normally we use 19 sqft and on the day with light wind we put 21 sqft). I guess that aluminium v bar became stretch due to aging ,recalled that we can't keep max tension of v bar through stricker rod(we adjusted the rod's nut until mast ball was almost touching the beam!!)...that was before sh_t happened.
