I've used old sash weighs as well. They work great for long lines when there is not a lot of current. I used to hunt in the Bay of Fundy, and when the tide runs you can watch your decoys drift away as the currents drag your set. Can get really frustrating when the birds are decoying to the end go the set!
I've tied several types of anchors. I've tried those folding grapnels - work the same if you tie the on or you just throw them overboard. I'm now using a 6-8 lb pyramid weight. I had a mould welded up for a 4 sided pyramid. It has a bracket that allows me to mount a stainless eye bolt or a bronze loop. They work ok, but I think next time I'd switch to a 3-sided pyramid that is a little bit longer relative to the width of the base.
The pyramid works well because it turns on its side and digs in as you pull on it. As I mentioned, I'd change he shape of mine to make them a little longer (taller). The shape I have now is a little short and when you pull on it it can tip over onto the eye. Note sure if you can picture it, if it was longer, (taller) the centre of gravity would be further back and might keep to digging in. The ones I have now work fine, but with a better shape I mine be able to get by with less weight.
Pyramid weights are used a lot on our salmon canoes. For canoe weights they often make the mould with the top cut off. I might try this with the next mould.
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