100 ft, 12 Gauge Heavy Duty Outdoor Extension Cord for $7.97
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Wouldn't another way to tell if it's really 12ga be to weigh the cord? 300' of 12ga copper weighs about 6lb, but 300' of 16ga copper weighs a bit over 2lb. Of course there's a lot more weight in the insulation, jacket, and connectors. Still, comparing with a known good cord of same length, there should be a noticeable difference.
Or another thought: How about using a load that won't blow out from undervoltage, like a 1750 watt electric frying pan or something, and then measuring voltage drop at the end of the cord compared to a known good cord? That Kill-a-watt could be handy for such a test.
May be a moot point as my order is backordered and the cords themselves are NLA.Last edited by tjr; 10-22-2009, 01:30 PM.Comment
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Wouldn't another way to tell if it's really 12ga be to weigh the cord? 300' of 12ga copper weighs about 6lb, but 300' of 16ga copper weighs a bit over 2lb. Of course there's a lot more weight in the insulation, jacket, and connectors. Still, comparing with a known good cord of same length, there should be a noticeable difference.
Or another thought: How about using a load that won't blow out from undervoltage, like a 1750 watt electric frying pan or something, and then measuring voltage drop at the end of the cord compared to a known good cord? That Kill-a-watt could be handy for such a test.
May be a moot point as my order is backordered and the cords themselves are NLA.
Weighing it would be another way, but its a bit clouded because they will be making up wire gauge drop by increasing insulation, which while less dense, will not be so obvious because as a percentage change from the whole weight of the cable, will be much less change than the change in resistance. Without looking up the density pf PVC and calculating the volumes and weight, lets guess in a good 12 gauge cord, there's 6 lbs of copper and 12 lbs of PVC (because of inner and outer jackets, and increasing volumes to the outside radius etc, even tho the density be maybe 1/3, the volume may be 12x as much as the copper volume). So take away 1.5 lbs of copper and replace it with 0.5 lbs of PVC, you've chnaged the weight from 18 lbs to 17 lbs. It'd be much less obvious. A 5% change in total weight is less obvious or conclusive than a 50% change in resistance or voltage drop.Last edited by LCHIEN; 10-23-2009, 05:39 AM.Loring in Katy, TX USA
If your only tool is a hammer, you tend to treat all problems as if they were nails.
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Incidentally Kaydee is right about pricing. Market prices for raw copper are about $2.90+ per pound (todays market price), 3 x 100 feet of 12 gauge copper wire would weigh just shy of 6 pounds, so raw copper for 12/3 would cost nearly $18. - not counting stranding, drawing and spooling the bare wire, insulating and spooling the inividual wires, then jacketing an filling the whole cable then attaching and molding the connectors, labor and materials, packaging and shipping. Even with free labor the Chinese can't do that.
1. They buy in large quantities, so the price is usually lower that spot.
2. They have contracts in place to buy materials for years at a specified price. If their contract says $1/lb for the next 3 years, that's what they pay, regardless of market price.
3. Some governments effectively subsidize materials cost - so the company may only pay $1/lb when market is $2.90/lb as a result of government subsidies, tax credits, etc. (our government does the same thing for some materials)
4. Until recently, copper prices were substantially lower. Given typical production cycles, these cords were likely manufactured 4 to 6 months ago - when copper prices were lower.
If the product is advertised as a 12 guage cord, however, the wire must be 12 guage by law or it's fraudulent advertising and a host of other infractions. I haven't encountered any such deception on the part of Harbor Freight, ever.
Now I'm curious, though - might just get one and check it out.--------------------------------------------------
Electrical Engineer by day, Woodworker by nightComment
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A couple of points that may result in their cost being lower than current spot market pricing:
1. They buy in large quantities, so the price is usually lower that spot.
2. They have contracts in place to buy materials for years at a specified price. If their contract says $1/lb for the next 3 years, that's what they pay, regardless of market price.
3. Some governments effectively subsidize materials cost - so the company may only pay $1/lb when market is $2.90/lb as a result of government subsidies, tax credits, etc. (our government does the same thing for some materials)
4. Until recently, copper prices were substantially lower. Given typical production cycles, these cords were likely manufactured 4 to 6 months ago - when copper prices were lower.
If the product is advertised as a 12 guage cord, however, the wire must be 12 guage by law or it's fraudulent advertising and a host of other infractions. I haven't encountered any such deception on the part of Harbor Freight, ever.
Now I'm curious, though - might just get one and check it out.
Yes, historically the low in the last 12 months was 1.27 per pound, so the copper content of a 100 ft 12 gauge cord would be around $7.62 if they bought 25 tons at the low point in the last year.
Yes, the Chinese government subsidizes business by pegging the chinese currency low to keep their products very competitive.
Still, assuming they bought 25 tons last year at the very bottom prices, $7.62 would only buy you a large ingot of copper which is a long way from a usable extension cord. And 37 cents left from $7.97 to make it more useful.
First you have to draw the fine wires, probably 19 strands per 12 gauge wire for not too flexible cord. Then you have to use a large winding machine to spin the 19 strands together to make a 12 gauge wire and spool it.
Then you have to shoot a jacket over each 12 ga wire in three colors. and respool it.
Then you have to take three spools and assorted spools of filler material (to make the final cord roundish instead of a triangle) and spin them into a 12/3 and then overshoot a PVC jacket over that with printing.
THen you have to cut to 100' lengths and terminate into plug contacts and then use a molding machine to overmold a plug body over that. testing, Packaging, shipping and markups somewhere along the line...
So you can see there's still a lot to be done for 37 cents after you buy the copper.Last edited by LCHIEN; 10-23-2009, 11:12 AM.Loring in Katy, TX USA
If your only tool is a hammer, you tend to treat all problems as if they were nails.
BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questionsComment
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