I'm looking for about 1km of thin-ish solid copper wire, as cheap as possible.
Solid, not stranded
To be used as single wires, in lengths of typically 10m
Could be insulated or bare, tinned or not; but not enamelled (unless the price was very, very right)
Strong enough to cope with being laid on the ground outdoors, and then generally trodden on and mowed over
Thin enough to be cheap.
About 1.0-1.5mm diameter would probably be fine.
In the catalogues, the best options so far seem to be multi-core cables of some kind. 12-core telephone cable is a reasonable price from TLC, though it's thinner than I'd prefer, and I'd rather not to have to strip and untwist it to get to the individual wires.
Solid twin bell wire from TLC would be fine, but significantly dearer per 100m of single wire. (Screwfix bell wire is stranded, so no use for this.)
Any better ideas from you intrepid bargain hunters, please?
You need to specify either cross sectional area, SWG, or what current it has to carry.
Single core insulated for electronic stuff is available from RS Components etc. Go up to normal mains - ie 1mm/sq and above and you'll get it at any electrical wholesaler. Single core is used in conduit, etc.
I don't see how any thin wire can satisfy "Strong enough to cope with being laid on the ground outdoors, and then generally trodden on and mowed over". I don't think even CAT5 or T&E can withstand these conditions long term.
Thanks very much for the replies so far. I really do appreciate how you lot get your teeth into an unusual problem!
But I misjudged the amount of detail that people might need in order to give a helpful reply. My apologies for that - I was trying to spare you all "the full half-hour". Well, here it comes...
This is a rather unusual application, and many of the normal electrical wiring requirements do not apply.
Yes, Andy, it is to make a ground mat for a radio aerial... well, four aerials actually! This requires the wires to be laid out in a fairly precise pattern of four radial fans, and the ends soldered to bare copper "busbars".
BTDT before, but only on a smaller scale requiring much less wire. This time I'm doing it at a new location and on a much bigger scale.
The amount of wire required - literally more than a kilometre - means that (a) I'll have to buy it, and (b) paying the odd few pence more per metre will add up to serious money.
The number of separate lengths of wires involved - approaching 200 - means I have to think about easy "mass production" techniques. Many of the things you wouldn't hesitate to do for a few tens of metres are simply not on at the kilometre scale. Wire's too long; life's too short.
That is an absolute requirement - please take my word for it. (At radio frequencies, the resistance of stranded wire becomes much higher when the strands corrode, as they inevitably will over the years. Solid wire is much less affected.)
From the performance point of view, it makes no difference whether the wire is insulated or not (see, I told you this was unusual).
BTDT - enamelled is a pain to scrape and connect, especially when doing it about 200 times, outdoors at ground level.
Sorry, Grunff, I may have misled you by not specifying the kind of surface. On grassy land, 1.5mm diameter copper is plenty strong enough for the basic radial wires - strong enough to trip someone up, and it will even stop a rotary mower (it cuts the wire, but the wire wins in the end, by strangulation).
The trick when laying wires on grass is to mow the grass very short first. Then lay the wires along the ground, heel down any sticking-up loops, or pin them down with thicker wire 'staples'... and then simply leave them. Just carry on mowing a bit higher than usual (which is where you find any loops that you didn't pin down properly) and within a year the wires will have disappeared under the root mat. It's quite remarkable. Within two years, you'll even have to search for half-inch cables.
As I said, on this scale the price per metre of wire really does matter
- especially bear>You need to specify either cross sectional area, SWG, or what current it >has to carry. >
I'd hoped to get away without having to go into details, Dave... but judging by some of the questions we get on here, you were quite right to ask :-)
For this unusual application, most of the normal electrical wiring factors don't matter at all. It all comes down to mechanical strength, and price.
If buying at normal catalogue prices, I'd rather spend all the money on copper than on insulation that isn't needed. However, plain bare solid copper seems to be the province of "instrument wire" suppliers, and is sold at a huge premium compared with the copper content of say T&E.
Stranded, alas. That is the >Or get some 7-strand conduit wire (say 10 or 16 mm^2) and strip out >the strands.
Because of the total length of wire involved, I'm afraid that would be far too labour-intensive. The same would apply to options such as stripping down scrap T&E. It's got to be some kind of wire that allows an easy "mass production" technique.
Tricky... but I really do appreciate your help and good thinking.
There is a low-temperature enamel which melts at (high) soldering temperatures. Tradename 'Quikstrip' afair, and is a light salmon-pink coloured enamel. Most of the en-cu in RS is Quikstrip I think.
Way overkill. If this is mostly over grass, cuut it very short, pin chicken wire flat against the ground and wait. After a couple of years, it will have vanished into the ground.
Or so I am told. My aerials are in bits in the orchard.
No - I contribute to several of those groups and lists, and can assure you that despite it being an unusual kind of DIY problem, here *is* the best place to ask.
Oh yes we do - and what I'm proposing is actually a little one.
For a serious earth mat that would put many broadcasters to shame, see:
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's about 40km of wire under there. I book-marked that page to remind myself occasionally that maybe 1km isn't so hard after all...
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