Drill through 15mm anchor shank

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I need someone with some decent drilling kit to drill a 10mm hole through the 15/18mm shank of an anchor. Plymouth area; does anybody know of a decent engineering workshop that needs some beer money?

tia

Rob
 
battery drill,cooling agent
mark, centre punch & drill a 3m/m pilot hole on the centre line of the hole.
then drill the 10m/m hole with a sharp hss drill bit on the slowest spd.


i have just driled 6m/m plate s/s this way for a backing plate. 4 x 8.5 m/m holes drilling took about 5 mins start to finish
 
Unless the anchor is s/st you'll be fine with a standard drill. I drilled a 10mm hole through the shank of a 20kg Rocna anchor (must be more than 15mm thick?) last weekend so I could fit the anchor pin. Did it in 3 goes - 4mm, 7mm 10mm. Five minutes max.
 
Bloody hell, whats all the fuss about, the cheapest battery drill would do that in about 5 mins flat! As the other sensible one said, do it in stages. As for the gas axe suggestion!! Really!!
Stu
 
As widely replied - task is a piece of piss if it is not stainless. Epoxy tar the hole I think if it's galvanised. No, I take that back - presumably you'll be lifting it with a shackle or some such stunt - which will bugger up any bodged coating.

With patience, a sharp high-quality bit and cutting agent you'll probably manage stainless with a respectable DIY drill.

Assume you are doing it for a good reason and have convinced yourself it won't compromise the strength of said anchor. Bound to void the warranty
 
Presumably for a pin to secure it ?


I must say I don't like pins for this. If they bend you are screwed. What is more the anchor still rattles so you have to tie it down anyway. Personally, I prefer a simple lashing.

I wonder what others think ?
 
Hmmmm......that is the manufacturers recommendation too. I'm still in two minds about whether to drill or not. I wasn't going to (following manufacturers guidance) and had devised a lashing to prevent fore and aft movement. I then realised that when the bow drops in to a wave trough and possibly submarines in to the next building wave there will be a good chance of the water hitting the anchor fluke and forcing the anchor upwards, the roller will not prevent this and such movement would mean the anchor bashing up against the pulpit. Hence the resignation to drilling and pinning the anchor to make it secure. The thought of the anchor flailing about uncontrolled in big seas is not a pleasant thought. I'm still undecided.

Rob
 
Those are the kinds of forces that could bend a pin. Every setup I have seen has the anchor sitting over the roller so that a tie down and back will lock it absolutely secure. On our CQR, when offshore, I also put a sail tie on the crown and tighten that back on board to stop any movement where the anchor articulates. As we come inshore I slip that. When in situations where the anchor might be needed in a hurry, I also convert the lashing to a slippery hitch.

If I had a pin, I would pull it under those circumstances and hold the anchor with a slippery hitch anyway.

Not of course saying that is the 'right way', just what I feel most comfortable with.
 
I've just modified my roller so it will fit the shaft of the Rocna. This stops it rolling (and hitting the forestay) and also holds it low enough to allow my pin to go through the exisiting hole on the Rocna. I, too, am a little concerned by the manufacturer's warnings about using a pin, but I was reassured on wandering round my marina to see a couple of Oyster 56s with 40kg Rocnas pinned in just the way mine is.
 
Yes, and on the Rocna Knowledge base I'm pretty sure there are examples of pinned Rocna's.

I can see what they say about not pinning but my Bruce has been pinned for the last five years without incident other than when we had a small yacht crash on to our anchor with quite a bang (in Yarmouth Harbour) and that did bend the pin. When I came to anchor I found I couldn't budge it and had to get the hacksaw out when back in the marina.

Rocna say that drilling a hole weakens the shank in direct proportion of the hole diameter to the width of the shank so I reckon drilling the hole will reduce strength by no more than 10%; nevertheless that is unwelcome!

Crikey; I'm even more unsettled now!

rob
 
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