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Old 11-10-2013, 17:51   #16
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Re: Making your own anchor - who has done it?

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Please pardon my ignorance, as I was unaware of the correlation between the change in material and the increase of incidences of bent shanks. I am surprised to learn this is true as Rocna lifetime warranties their anchors against bending.

Of course their warranty applies when their user guide has been applied. Funny thing, the User Guide states specifically that the anchor is not designed for rock or coral. To figure. Huh.

Anybody got an anchor for rock and coral that is warrantied against bending? Good luck with your anchor project.

OK just for a moment I'm going to assume that you are really being truthful here.

And in that case a little searching of this forum and YBW will give you thousands (10 thousand?) of posting on the evolution of Rocna from bis-plate (800 MPa steel) to 400 MPa steel to 620 MPa steel.
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Old 11-10-2013, 18:01   #17
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Re: Making your own anchor - who has done it?

i am building mine next year. i will use stainless.
its very cheep, if you make it yourself. even if you have a fab shop make it, it would be very cheap. the ronca is what i will make.
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Old 11-10-2013, 18:11   #18
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Re: Making your own anchor - who has done it?

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OK just for a moment I'm going to assume that you are really being truthful here.

And in that case a little searching of this forum and YBW will give you thousands (10 thousand?) of posting on the evolution of Rocna from bis-plate (800 MPa steel) to 400 MPa steel to 620 MPa steel.
I don't come here to lie, I can do that at home in real life all I want. Seriously this is news to me, I tend to stay away from anchor threads.

The 'make your own' bit is what got me here and now the seed is planted (thank you for that) there is probably a good chance I will end up making my own. I have all the resources, so why not? It ain't rocket surgery.

That said I am interested to hear about the business with the materials change. I'll have to do some reading. Seems to me like if you change materials you would change the the thickness or width accordingly, like duh.

But what do they say when you try to get warranty coverage? That you didn't follow their User Guide? Just curious.
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Old 11-10-2013, 20:16   #19
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Re: Making your own anchor - who has done it?

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I don't come here to lie, I can do that at home in real life all I want. Seriously this is news to me, I tend to stay away from anchor threads.

The 'make your own' bit is what got me here and now the seed is planted (thank you for that) there is probably a good chance I will end up making my own. I have all the resources, so why not? It ain't rocket surgery.

That said I am interested to hear about the business with the materials change. I'll have to do some reading. Seems to me like if you change materials you would change the the thickness or width accordingly, like duh.

But what do they say when you try to get warranty coverage? That you didn't follow their User Guide? Just curious.
This thread is not about Rocna so lets all not go there. I'll post some links for your interest. Then we can get back to building anchors ouut of high strength steel.

78 pages :

I hate to do this...but

Plus just search "grant rocna" on this forum.

Now back to making our own new age anchor of any design. (please)
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Old 11-10-2013, 21:05   #20
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Re: Making your own anchor - who has done it?

All I can say is, I hope the ins surveryer can't tell it's home made!! and be sure your Ins Co don't know about it ! cus they might just limit your policy or cancel it! just sayin it better not look home made !
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Old 11-10-2013, 23:28   #21
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Re: Making your own anchor - who has done it?

It is not possible to galvanise steel with a tensile strength above 800 MPa as the heat of the galvanising will destroy the tensile strength imparted in the tempering process.

This limits the steel to be used as 800 MPa or less and both Manson and Anchor Right already use such steels (typically 800 MPa).

Further issues, you would need to find someone with a pretty decent press, to even bend 800 MPa steel. 800 MPa steel needs considerable care when welding. 800 MPa steel is also difficult to cut, at home - you need a laser or water cutter to do it properly.

800 MPa steel is quite pricey - so get your design sorted out before you start to use the hard stuff.

These complexities maybe a reason no-one else has gone down this path but it explains why no-one uses steels with a higher MPa (than 800). Armour plating steels come in at about 1,400 MPa.

Interestingly the reality is no-one (customers) is in the least bit interested in, even, 800 MPa steels for shanks (let alone anything stronger) - there is no indication that customers are beating a path to either Anchor Right nor Manson's door and then standing in line (or queuing for the anglo saxons) for their 800 MPa product. People seem quite happy with shanks of no known steel quality (or at best with a strength much less than 800 MPa).

So an interesting project - but very niche and huge technical issues.

Jonathan
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Old 11-10-2013, 23:44   #22
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Re: Making your own anchor - who has done it?

Here is some inspiration

I cannot see the shank bending easily.

It was fabricated locally, under strict quality control procedures. Super high holding certification is pending
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Old 12-10-2013, 04:26   #23
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Re: Making your own anchor - who has done it?

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It is not possible to galvanise steel with a tensile strength above 800 MPa as the heat of the galvanising will destroy the tensile strength imparted in the tempering process.

This limits the steel to be used as 800 MPa or less and both Manson and Anchor Right already use such steels (typically 800 MPa).

Further issues, you would need to find someone with a pretty decent press, to even bend 800 MPa steel. 800 MPa steel needs considerable care when welding. 800 MPa steel is also difficult to cut, at home - you need a laser or water cutter to do it properly.

800 MPa steel is quite pricey - so get your design sorted out before you start to use the hard stuff.

These complexities maybe a reason no-one else has gone down this path but it explains why no-one uses steels with a higher MPa (than 800). Armour plating steels come in at about 1,400 MPa.

Interestingly the reality is no-one (customers) is in the least bit interested in, even, 800 MPa steels for shanks (let alone anything stronger) - there is no indication that customers are beating a path to either Anchor Right nor Manson's door and then standing in line (or queuing for the anglo saxons) for their 800 MPa product. People seem quite happy with shanks of no known steel quality (or at best with a strength much less than 800 MPa).

So an interesting project - but very niche and huge technical issues.

Jonathan
Well, if it's a DIY anchor and not for a mass market then doesn't have to be galvanized. Could be protected against corrosion with paint or lanolin.
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Old 12-10-2013, 04:32   #24
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Re: Making your own anchor - who has done it?

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Well, if it's a DIY anchor and not for a mass market then doesn't have to be galvanized. Could be protected against corrosion with paint or lanolin.
Good luck

All you need now, that a corroding anchor is acceptable, is some way to bend it and/or some considerable skill to weld it not to mention cutting out the various shapes. Has anyone ever tried to cut a 1400 MPa steel with a hack saw? You could oxy cut it - but the edges will not be 1400 MPa anymore.

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Old 12-10-2013, 04:38   #25
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Re: Making your own anchor - who has done it?

Hi Scoobert,

Making a stainless anchor for yourself is relatively cheap and easy depending on the quality of stainless, the finish only has to please yourself, unfortunately when a customer wants a stainless anchor he wants one with a mirror finish and maximum strength otherwise he simply doesn’t want it at all.

To produce a shiny master piece then the price becomes Quite reticula’s too many when they price up stainless, they simply cannot see where the cost is.

I myself would sooner not make stainless anchors at all but there are the ones that want them at any cost. 302 stainless is out of the question as it will readily rust, unless there are two types of 302 one that I obviously don’t know about?

Stainless is relatively soft, once bent if you try to straighten it then work hardens, the next time you bend it, it will snap.

We are certified anchor manufacturers that produce anchors for S/H/H/Power certification, 316 in the shanks simply will not take the loads required for this, I should point out, this is in our designs, to appease the authorities we use 2205 stainless approx fifty per cent stronger than 316 to comfortably reach the proof load testing that is required for certification, note, comparing 302 stainless to the price of 2205 stainless your home made price will suddenly not become so cheap.

Many times I ask the customers why do they want stainless, they say well it doesn’t rust and simply the boat I own just have to have shiny anchor, I will then go on to try and discourage them by explaining the truth, stainless is quite soft as compared to Bis plate, Bis plate being around two and a half times stronger with great flexing properties, stainless will simply not flex and yield, I then give them a price of around three and a half times more for a mirror finish anchor and they still say I want it.

And yes by all means make your own anchor it could be fun, if your boat is under survey you have wasted your time, it is also advisable to check with your insurance company that your anchor is of your own creation just so there are no surprises after all the hard work.

And incidentally if you beef up a cheap stainless shank for a Rocna copy, you just may find your copy falls well short of the genuine ones performance.

Regards Rex.

CEO of Anchor Right Australia.
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Old 12-10-2013, 04:40   #26
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Re: Making your own anchor - who has done it?

Uh hack saw? Why would I do that when I can have the robot water-jet cut it out all pretty? Bending it, how thick are we talking? Hardness and temper? Wouldn't that occur after fabrication?

Why so serious?
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Old 12-10-2013, 04:50   #27
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Re: Making your own anchor - who has done it?

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Uh hack saw? Why would I do that when I can have the robot water-jet cut it out all pretty? Bending it, how thick are we talking? Hardness and temper? Wouldn't that occur after fabrication?

Why so serious?
One assumes that person posting is relatively serious. Laser or water jet cut, a one off, I shudder to think of the cost - have you ever costed cutting 1400 MPa steel? You need two steel plates, one for the fluke and one for the shank.

The suggestion was using armour plating steel.

Amour plating steel is made to a very tight chemical specification (as are all Q&T steels). I doubt you can buy a 4' square piece (at all) to any of the Q&T specs (for Q&T steels above 700 MPa). The tempering process is tightly controlled, by that I mean temperature, soak time and cool rate, and I'd guess it impossible to find anyone with the skills capable of tempering for you - its not a skill used by many (and its not skill sold on the internet, as far as I know)

But as jokes go its a good thread

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Old 12-10-2013, 04:51   #28
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Re: Making your own anchor - who has done it?

While strength is a major consideration, so is electrolysis.

Matching your rod or wire to the steel of the anchor body is advisable
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Old 12-10-2013, 04:53   #29
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Re: Making your own anchor - who has done it?

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While strength is a major consideration, so is electrolysis.

Matching your rod or wire to the steel of the anchor body is advisable
What rod or wire

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Old 12-10-2013, 04:57   #30
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Re: Making your own anchor - who has done it?

Most arc welding is done with sticks of metal (rods) or wire feed units (wire).

Torch welding is possible but not used as much. I guess if you wanted to be a real purist, you could hammer weld it, but there goes the original tempering.
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