Bonjour

For the scientists there is a Excel model of the dynamic dehavior (with wind, blows  and waves) of a mooring.

I'm sorry it's both in French and in metrics!!!

Be carrefull, the compressed file is 14 Mo !

For the others there are nice pictures on the blog, but from a pointy.

http://artimon1.free.fr/docstechniques.htm

Eric

A good article on when this device is, and isn't, useful.

Basically, in extremis, it will do very little to increase holding power, and the better solution is to take the weight of the device and incorporate that weight into the anchor. Or, the biggest 'new generation' anchor that you and the boat can manage is the best way to maximise holding power.

But:

"Other applications:

This is not to say that kellets are entirely pointless; they serve other purposes.

They can contain and minimize swing radii in light conditions

They can help dampen “sailing” at anchor

They can keep a boat stationary when using bow and stern anchors

They can help ensure that rode is kept down and away from the boat’s keel, rudder, and propeller."

- and the last mentioned is the particular need that I have.

Another possibility is old sash window balance weights. These are cast iron and have a loop cast in at one end. They come in several weight sizes between about 4 and 8 kg and would be ideal for the job once coated with epoxy and then the neoprene rubber that is sold for coating tool handles. They can be picked up for very little money from most scrap yards.

I cast the 5,000 kg keel for Arcadian and Arne is right about the moisture, we had quite an impressive boil from some hidden moisture that had got into the mould before we poured the lead. Also be aware that the fumes from molten lead are highly toxic so a suitable gas mask should be worn when working anywhere near the melting pot.

David.

David Tyler wrote:

Arne Kverneland wrote:

Cast your own chum

It doesn’t take rocket science to cast a lead anchor chum. From an auto tyre workshop one is likely to get used balancing weights for free, or very cheaply.

Then, all it takes is a gas or primus stove, a tin can of suitable size, and a ring bolt (dipping a stub of anchor chain doesn’t work as it floats in the molten lead). One could even cast the chum into a flattish shape (in a dry sand or cement pit), to give added hydrodynamic damping if the boat is pitching.

Arne

 

No, but it does take some attention to Elf and Safety considerations. Wear leather gauntlets, eye protection and natural fibre clothing, and keep the kitchen door open (for ventilation and to provide an escape route). Use a stainless steel saucepan, of the pot-bellied type (so that the lead will remain inside once solidified). Melt the lead and then leave it to solidify on the stove. Do not attempt to carry a pan full of 8kg of molten lead.

Only worth doing if you already have 8kg of lead. Otherwise, just spend a few £ or $ on a kettlebell.

The feedback I got from sailors on Facebook who have needed a chum is to look for second hand diving weights, and when you have enough, thread them onto a length of webbing.

 I used a discarded copper bottomed stainless steel tea kettle with the small spout lid removed and electric hot plate along with used wheel weights for a small job. I don't know if doing this way has any unforeseen greater risk but carrying and pouring should be less hazardous than with an open pot. It's an outside or highly ventilated area job. I worked to avoid the fumes, like a plague.  I'd want to coat the chum well with something (epoxy?) before handling and using it bare handed.

Cast your own chum

It doesn’t take rocket science to cast a lead anchor chum. From an auto tyre workshop one is likely to get used balancing weights for free, or very cheaply.

Then, all it takes is a gas or primus stove, a tin can of suitable size, and a ring bolt (dipping a stub of anchor chain doesn’t work as it floats in the molten lead). One could even cast the chum into a flattish shape (in a dry sand or cement pit), to give added hydrodynamic damping if the boat is pitching.

Arne