Electric slug fence

[Pete C]

Martin, any chance of a wiring diag, and source of capping? :)

[Andrew Gabriel]

PP3 (9V) battery, in series with a 470 ohm resistor and a high efficiency LED (plus the earth rod resistance). The LED lights to tell you there's some leakage current (high efficiency one means you can see even fraction of a milliamp leakage at night). It flashes quite brightly when a slug touches the contact. Given the dramatic effect on a couple of slugs and a snail which I saw approch it last night, I suspect a much lower voltage would work fine too. It's probably not safe to use such a scheme if you have livestock nearby, due to their vulnerability to very low earth leakages.

Construction is 25mm PVC conduit with 12mm galvamised capping screwed to the top. The profile of the capping is perfect for rain water shedding from the top. I tried a deluge from a watering can rose, and even that didn't cause the LED to light. Just touching the rail whilst kneeling on the ground generates enough current to light the LED though. Water droplets bead on the surface of the PVC, so it won't conduct. It might be that it needs lifting and wiping clean occasionally to maintain this, but I haven't had it deployed for long enough to know yet. Ground needs to be very level. I filled in a couple of dips under the fence with some old building sand. A couple of tiny slugs appeared inside the area, presumably sleeping inside the fence when it was positioned. After removal, no more were seen inside. I'll keep an eye out over the next few nights. Can easily test the battery just by touching the rail and ground with a hand. Operation probably requires that the area stays damp, but a) that's needed for the plants anyway, and b) slugs don't tend come out when the ground is very dry.

[Bob Minchin dangling via a don]

Why do you need a circuit diagram? It is described in the thread in words. Capping could be made from standard top hat section electrical wiring protector.

Bob

[alan.holmes]

I thought I knew something about electrical bits, but what on earth is 'standard top hat section electrical wiring protector'?

And where do you get it?

Alan

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[Andy Burns]

[Dave Liquorice]

standard = commonly avialable in a range of set sizes. top hat section = when looked at end on the shape is like that of a top hat (al beit one without sharp corners). electrical wiring = er, do I need to explain that? Normmaly mains. protector = Placed over the wiring before plastering it offers a little bit of protection to the wiring.

Any electrical wholesaler, I don't recall seeing it in DIY sheds, only round and oval plastic conduit.

[alan.holmes]

Thanks, just realised what he was talking about, I would not have thought of using that description, but I have installed wiring using that stuff.

[Andrew Gabriel]

So after a few days, how's it doing?

Before I made it, every new shoot was eaten back level with the soil every morning. Since making it, only about 1/6th of the shoots have been eaten back to the ground, and another 1/6th have some damage. I've checked a few times during the dark, and found there were still some small slugs and one tiny snail, which I have removed. Difficult to tell if they're getting in, or were in to start with, but I suspect probably some of each. Trying to search the whole area in the dark even with a bright torch was not easy. Then I realised that each one I had found had its jaws on one of the new shoots, and because they're planted in a strict pattern, they're actually quite easy to find now.

[moghouse]

Do you think it would be possible to make the Electric Slug Fence an obstacle in three day eventing?

[Jules]

I suspect the horses could jump it with ease.