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Old 04-20-2011, 11:21 AM   #101
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RE: Rocna revealed

Just bought a new 33# Rocna from a guy caught up in the hype. $170. Soon as I get it home I'm going 'proof' it out in the pasture with the tractor and 3/8" log chain. If it comes apart I'll weld a draw bar on it and turn it into a single bottom garden plow. If it doesn't I'm going to hang it on the front of my Taiwanese trawler.

Gunna be a week or so...but I'll report back.
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Old 04-20-2011, 11:40 AM   #102
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RE: Rocna revealed

Chip,

You should be able to get an almost non-destructive hardness test somewhere near home. Call a machine shop. No need to get savage with the thing.
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Old 04-20-2011, 01:20 PM   #103
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RE: Rocna revealed

Quote:
Anode wrote:
Just bought a new 33# Rocna from a guy caught up in the hype. $170. Soon as I get it home I'm going 'proof' it out in the pasture with the tractor and 3/8" log chain. If it comes apart I'll weld a draw bar on it and turn it into a single bottom garden plow. If it doesn't I'm going to hang it on the front of my Taiwanese trawler.

Gunna be a week or so...but I'll report back.
*Chip, my guess is it won't come apart, but if it is a Chinese made with a shank of A36 mild steel, you'll be able to bend the shank quite easily.* The shank is designed to be made of the high tensile steel they claim they use to prevent the kind of bending you see in the picture on my first post.* That anchor was off a Bavaria 49, 11 ton displacement, anchored in Venice harbor, reported sandy bottom, 110' chain, 17-20 knots of wind for 24 hours.* When retrieving with the windlass, the owner said he felt resistance, continued to pull with the windlass, and the anchor came up as shown.* I won't take much to bend the shank if yours is like this one. In fact, the number I saw posted elsewhere is 317kg for the 33#, applied at 90 deg to the shank.* Have fun, and let us know!

*
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Old 04-20-2011, 02:43 PM   #104
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RE: Rocna revealed

This is getting, well intersting. Would the graduate metallurgists on Trawler Forum sign in please. FYI, the notion that a "SS" steel anchor is stronger than a "mild steel" is dubious - one has to define the type of SS and mild steel. Anode, while you are at it, do the same garden test with a Sarca, Bruce and Danforth. Otherwise your plow test may be misleading!

As stated by Capt Cook and others, my Bruce is looking better all the time.
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Old 04-20-2011, 03:25 PM   #105
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RE: Rocna revealed

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sunchaser wrote:
...*my Bruce is looking better all the time.
*Ditto!

*
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Old 04-20-2011, 03:30 PM   #106
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RE: Rocna revealed

It looks as if PeterB is the only one on this page needing an anchor.* None of the other boats showing are in the water!
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Old 04-20-2011, 03:34 PM   #107
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RE: Rocna revealed

Quote:
Moonstruck wrote:
It looks as if PeterB is the only one on this page needing an anchor.* None of the other boats showing are in the water!
*You noticed that too.* Must be*the season.

*
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Old 04-20-2011, 05:09 PM   #108
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RE: Rocna revealed

Quote:
sunchaser wrote:
This is getting, well intersting. Would the graduate metallurgists on Trawler Forum sign in please. FYI, the notion that a "SS" steel anchor is stronger than a "mild steel" is dubious - one has to define the type of SS and mild steel. Anode, while you are at it, do the same garden test with a Sarca, Bruce and Danforth. Otherwise your plow test may be misleading!

As stated by Capt Cook and others, my Bruce is looking better all the time.
Tom, good point on the mild steel, which has a pretty broad range of types and to know what you're actually talking about, you have to specify the type.* The most common is A36, which has tensile strength right in the range the Rocna tested, so maybe that is what they are using.* 316L stainless is what is frequently used for anchors, at least that is what the Ultra is made of.* If you're comparing A36 to 316, the 316 has greater tensile strength.* The Ultra is a lot stronger than that because they use a box design on the shank.* The main issue with mild steel being used on the Rocna is how thin the shaft is.* On my Bruce, it must be 1 1/2" thick, but on the Rocna a lot thinner, which is why Rocna specifies true high tensile steel for that component, although they didn't use that steel on the anchor tested in NZ.

*
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Old 04-21-2011, 07:18 AM   #109
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RE: Rocna revealed

*I thought that you would like you know .*24 May is National swim day here.

*I paint all my anchors with white undercoat paint, because i think that they look nice on my bow.

Other colors under consideration are red and Harley Davidson Orange.

**Then again, you could paint a sharks jaw *& *scary eyes just like the Flying tiger WW11 fighter planes had.

*

*
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Old 04-21-2011, 08:02 AM   #110
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RE: Rocna revealed

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SOMERS wrote:
*I thought that you would like you know .*24 May is National swim day here.

*I paint all my anchors with white undercoat paint, because i think that they look nice on my bow.

Other colors under consideration are red and Harley Davidson Orange.

**Then again, you could paint a sharks jaw *& *scary eyes just like the Flying tiger WW11 fighter planes had.

*
*Perhaps a flame job?

*
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Old 04-28-2011, 07:53 PM   #111
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RE: Rocna revealed

Well I got my $170 33# Rocna today. Brand new, never in the water. "Made in Canada". Gunna pass on the 'tractor test'.
I'm a happy guy.
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Old 04-28-2011, 08:13 PM   #112
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RE: Rocna revealed

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Anode wrote:
Well I got my $170 33# Rocna today. Brand new, never in the water. "Made in Canada". Gunna pass on the 'tractor test'.
I'm a happy guy.
*If it has no stampings on the bottom of the flukes, then it would be made in NZ or Canada, in which case, it is made to the specifications Rocna advertises.*

*
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Old 04-29-2011, 04:57 AM   #113
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RE: Rocna revealed

No stampings on bottom of flukes, welded plate not cast and a metal Rocna label on the shank which states 'Made in Canada'.

Got more on the story of where it came from. The fellow I bought it from bought it at a charity auction at his marina. It was donated by a friend of his that bought it several years ago and never used it. Both thought it was too big for their boats is the story I'm getting. Anyway, my purchase money is being donated back to the charity by the fellow I bought it from.

I'm keeping the anchor and naming it "Charity".
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Old 04-29-2011, 03:30 PM   #114
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RE: Rocna revealed

Anode, you will be fine with that anchor, I'm sure. I look forward, as we all do, to your report after your first outing using it for overnight anchoring.
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Old 04-30-2011, 03:21 PM   #115
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RE: Rocna revealed

Hosted my third guest Krogen Manatee in a month right here at the dock, and he's been a die hard Rocna fan who swears by his 44 pounder....says he sleeps without a worry. Now in all fairness, this guy probably anchors three times a day on his three to four month stays in the Bahamas, but he admitted that he did call Rocna about the bending shank. He says they got back to him to say there may have been a compromise in the alloy of his unit. No further communication as of this posting.
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Old 04-30-2011, 08:38 PM   #116
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RE: Rocna revealed

Quote:
healhustler wrote:
Hosted my third guest Krogen Manatee in a month right here at the dock, and he's been a die hard Rocna fan who swears by his 44 pounder....says he sleeps without a worry. Now in all fairness, this guy probably anchors three times a day on his three to four month stays in the Bahamas, but he admitted that he did call Rocna about the bending shank. He says they got back to him to say there may have been a compromise in the alloy of his unit. No further communication as of this posting.
*Rocnas current approach is to blame the emerging reality that their shanks are made of mild steel, and not the high tensile required for the design,* on an employee/consultant they fired about a year ago.* Problem with that is that they have been apparently been shipping the same metallurgy for 3 years, including a year after the guy they want to blame it on was fired.* Sad situation, because it is a very good design deeply compromised by what looks like unethical owners.* If you own one made in Canada by Suncoast or in NZ you are probably fine.* If you own made in China you got punked, or so it appears.

A simple test can be made with a steel center punch.* Rocna advertises that their shanks are made of 800 MPa steel.* Hit that with a center punch, and the center punch will yield, not the 800 MPa.* The steel that Rocna has been sneaking into their shanks will indent nicely.* The force is kind of immaterial, but a tap is all that is needed.* If you ruin your center punch on your Rocna, it's made to spec.* If you indent it, it isn't.
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Old 05-01-2011, 06:00 PM   #117
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RE: Rocna revealed

I decided to eat my own dogfood and test a Rocna myself.* Since I very much need an easily handled stern anchor, I decided to buy the Rocna 22# shown below at West Marine.* I figured that if it passed the center punch test, I'd have a good stern anchor that I could also use on the Whaler, but if it failed, I can always take it back since it would have been falsely advertised.* The pictures below show the results of the test.*

To start, I used a steel center punch on a piece of mild A36 channel I had lying around.* The force used was what you would use to mark a drill spot.* The dimple made is shown in the second photo, and the whole piece of channel next to the Rocna in the third.

I then used the same force on the fluke of the Rocna and made the dimple shown in the fourth picture. Rocna says the flukes are made of mild steel.* The fifth shot is the dimple made in the shank, which Rocna says is made of 800 MPa high tensile steel.* As you can see, the dimple is the same basic indent as that created on the channel, and the Rocna flukes.

To have a reference point of steel with known hardness at the other end of the scale from mild steel I used one of my Japanese chisels, which the catalog shows has a hardness of Rockwell 63, Brinell 255 or exactly the same as 800 MPa steel.* I was at first worried about trying to duplicate the same force on the test on the chisel to be fair.* I need not have worried.* The chisel, shown in the sixth picture was unscathed other than scuffing off some smudge left from woodworking.* The center punch however, as shown in the seventh picture is ruined.*

I'll decide soon whether I return this anchor as is, or have it further tested, but I thought this indication that the allegation that Rocna is not making their anchors out of the materials they say they are making them out of would be of interest.

Since the Rocna is designed with a thin shank to get the weight distribution optimized, the use of the specified grade of steel is essential if the anchor isn't to present a probable risk of bending under normal side loading and a danger to boaters.* Since these anchors set extremely well, the likelihood of side loading one is increased as they are retrieved from deeper burial.
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Old 05-01-2011, 06:23 PM   #118
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RE: Rocna revealed

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Old Stone wrote:
Delf - So you takin' that anchor back to West Marine? Do you think they will just reshelf it and sell it again? Great shots that certainly prove a point!
*Carl, I think WM is in a real quandary.* Rocna has done a great job of creating a brand by using the Internet to promote the idea that anything less than a Rocna is an inferior product.* WM is responding to demand for the product, so whether they feel the need to do a recall of a few thousand of them sold to customers who thought the product was made as advertised, or whether they just deal with problems as they come up, I don't know.* Frankly, I don't see how an ethical company like West Marine would want to continue to sell these after it was shown that they, like everyone else was scammed.* Time will tell.
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Old 05-01-2011, 07:39 PM   #119
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RE: Rocna revealed

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Mike wrote:
I am in the Computer Numerically Controlled - CNC- machining business.

95 percent of the parts I make are for aircraft, and almost all of them are for military aircraft.

I'm too small to deal directly with the DoD so I work for Fortune 100 companies that deliver finished products to the military.

All of my customers require full "Certifications" of the material we use in making their parts. This is a paper trail that goes al the way back to the mill where the material was made.

My stock man will refuse a delivery if the supplier can not provide the cert. papers.

I can't even store certified material in the same room as uncertified material.

I think some marine manufacturers would benefit from ISO 9002 standards.

Mike
Merritt Island, Fl.
*Well, that's another interesting aspect to the Rocna story.* They claim to have RINA certification, but don't.* They claim to have SHHP certification, but don't.* If you tell them about ISO 9002, they'll claim they have that too.* But won't.
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Old 05-02-2011, 07:31 AM   #120
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RE: Rocna revealed

Delfin - Send me your new Rocna and I'll give it the 'tractor test'....hehehe.
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