I see this is getting a lot of reads right now, so I've made it more current.
I buy metal at yard sales for scrap, and this is a tutorial passing on some of my experience. I will address each type of metal in turn, both precious and non-precious.
You may notice I don't know everything, and that I may even be wrong on some points. I'm also very interested in what you know. Please let's make this a two way street.
First, the most important pointer of all - bring a powerful magnet. There are "super magnets" on the market and they're all I use. Your local hardware store should have them for sale for a little less than a dollar apiece. Keep these away from your credit cards, and anything else you think might be erased by magnetism.
And a style note: I will refer to things as being "magnetic" or "non-magnetic". What I mean to say is the metals are or are not attracted to a magnet. In reality, it's the magnet that's "magnetic", but it's a lot easier to be ungrammatical. If this bothers you, my condolences.
Iron and Steel:
The global demand for iron and steel is greater than ever, mostly because of growth in the Chinese economy, but also other countries are using the metals is greater quantities than they have in the past. Many iron mines are in mothballs, and it's just simply cheaper to find some steel lying around that it is to make it from rocks. Because of this the demand for iron has gone up greatly - to $200 a ton. That doesn't sound like much, but remember, it's heavy and plentiful stuff.
When the price declined because of the Great Recession, the dealer I was selling scrap to refused to take any amounts of less than 500 pounds, but it didn't take much looking to find a place that would take any amount, and this leads me to an important point; not all scrap yards are created the same. Shop around.
Iron and steel are highly "magnetic". Keep a good hold on your super magnet, or it will be yanked from your hand with a head turning "clack". It will also pinch your finger against the metal, if you're not careful.
Since the value of steel has risen, you may want to take the time to talk with your scrap dealer about different grades of steel. I know that nuts and bolts and steel food cans are higher-quality steel and thus bring a higher price. I also just pulled a roll of galvenized (zinc-coated) chain-link fence from the dumpster in my highrise, and you can be sure I'll be asking the dealer if galvenized fetches a higher price than run of the mill iron or steel.
What to look for: It's usually "brassy" in color, but there are also other, heavy and dull silver-colored items that the scrap yard buys for the same price and calls "white brass". Brass we usually find is usually in the form of candle sticks and figurines, but investigate anything that has that telltale color. The best way to tell if an item is brass is if it is brass from India, which is slightly magnetic to your super magnet. Apparently quality control is not so great in South Asia, and a bit of iron makes its way into the products made there. Perhaps it's intentional; I wouldn't presume to know, to tell the truth. When in doubt, set pieces aside in another box. A good scrap dealer should be patient in checking them out. Again, if you find them impatient or condescending, don't say anything right away (because you might be coming back). Shop around for a more friendly buyer.
So, why is it a good thing that any brass would be slightly magnetic? Wouldn't that be confusing? Well, it gets even more confusing. There's a metal out there that masquerades as brass, and it's called die-cast. Die-cast, like stainless steel, is not magnetic - not even a little bit - and back when brass was bringing $1.70 a pound, die-cast was bringing about $.30 so you can get burned pretty easy.
Fortunately, die-cast is silver in color, and is thinly plated with a brassy covering. Unfortunately, you can only discover the ruse by grinding off a bit of the covering, revealing the different color underneath, and you can't very well do this before buying something.
Here's the rule of thumb. Most "brass" lamps, with hollow bulbous sections are in fact die-cast. Many items of similar size are also made from die-cast. If you can see inside (and usually you can not) die-cast tends to have a rough interior surface, while true brass does not. The best rule of thumb is if it looks like brass, but too big and good to be true, it probably is not brass. If you can loosen the parts of a lamp and tap it and it "rings" when struck, it's more likely to be brass. Die cast doesn't ring well at all. Also, where I sell my brass, the price is back up to $2, so it might be worth some bother to figure it out. Remember, you may luck out and notice that it's slightly magnetic, and if so buy it. But if it could be die-cast, don't buy it unless you're getting it for next to nothing.
Did I mention that "brass" lamps are the worst offenders? Of course I did. You've been warned and reminded.
After brass, the metal I most look for is sterling, which is most easily identified because it is stamped with either "sterling" or "925". Pure silver is not strong enough for many of the purposes it is used, so a small amount of something else is added. What that something else is does not matter for our purposes; what we need to remember is that sterling is 92.5 percent silver (hence the "925").
I am not an expert on silver, so I watch for the 925. Other things may say "Acme Silver Company" or "Dr. Bozanko's Silversmiths". Maybe they're silver. Maybe they're not. I don't know, so I watch for 925.
Couldn't anybody just stamp 925 on something that isn't silver? Yes, but. As valuable as silver is, it's not worth getting caught trying to pass something else off as silver. Fraud is a pretty serious crime, and since it's impractical to fake one or two items, a perpetrator would need to do thousands af fakes to make it worth the time. I also have a certain faith in the goodness of people. Lest you be inclined to be slightly racist and say "Well, it's says it's silver but it also has 'Mexico' stamped on it" - have you ever seen the inside of a Mexican prison?
Tread carefully here, because you may be tempted to pay a lot for "gold" and get burned. My comments about gold are going to be more a caution than anything else.
If you're going to buy gold, you'll need a really good scale that weighs very small amounts accurately.
I grew up in the mountains. Hand me a rock with a speck of "gold", and I'll tell you if it's gold or not.
First of all, gold rarely forms crystals, so as I've hold thousands of tourists over the years "if it glitters, it's not gold." Gold is also always gold colored; it never fades or tarnishes. If anything else had the same color, it would be only be by chance that it had that exact color. This can help you, if you have the luxury of carrying something gold with you, because you could compare, and if the item being offered for sale isn't the same color, I advise you walk away.
And what color is that? This, below is gold. It never comes in any other color. Now, look at the rock above. Where's the gold? See what I mean?
But it's very easy to gold-plate something. So, look for marks that say 18K or 14K.
Pure gold is 24K, so don't let yourself get excited and forget that 25% of an 18K item is something other than gold. 14K items are closer to being half not-gold.
So, bring your scale and a calculator. How much does the gold weigh? Two grams? Okay, divide 2 by 31.1 (gold is measured in troy ounces, which is a different number of grams than a regular ounce). Then have the percentages of gold you would find in 18K or 14K gold written down, and multiply that by the fraction of an "ounce" you already have on your calculator. This will give you the exact weight of pure gold your item contains. Now, don't multiply by the spot price you find on the internet. Rather, know how much your buyer is paying for gold right now; that person needs to make a profit and will not be paying spot price.
Another thing that makes me nervous is that the price of gold fluctuates a lot (and not always on the upside either). Keeping up on the price and trend may more hassle than you want, and if so, stick to less-valuable metals.
Do you have any pointers for me? How can I be comfortable buying something gold and knowing I'm not making a mistake?
Never, ever melt down gold or silver before selling it. When you do this, you lose the markings that document its purity. And even though the buyer can test the purity with various chemicals, they cannot know whether there's a big chunk of lead hidden inside. They will not be shy about telling you this.
Aluminum is everywhere, and I'm on a mission to rid the world of aluminum cookware. The beauty of aluminum is the ease of identity. It is never magnetic, and it's unusually light.
Don't get fooled because it's heavy though. Pressure cookers? Aluminum. "Mag" truck rims? Aluminum. If you're looking for aluminum, don't forget looking in the free box at sales. Non-stick skillets are regarded as worthless once they have a few scratches in the coating, but they're still aluminum, and the scrap yard doesn't care if they're coated with something.
The last time I checked, aluminum was bringing about 50 cents a pound at the scrap yard.
The main thing to look out for in gathering aluminum is the labor involved in separating it from other non-aluminum parts. Leave even a few steel rivets attached, and it's reclassified as "dirty aluminum", which brings about one-fifth the price. If you're still going to decide you'll buy it and disassemble it, get yourself some appropriate tools. I have two sizes of bolt cutters, a hack saw (usually worthless, but I own one anyway), an anvil with a vise attached, and a power metal cutting saw. Sometimes a well-placed whack with a hammer will break things loose that would have taken much longer to cut. The most important thing to know is when to ""go caveman with it. Don't overthink it. If it looks like smashing or prying might be equally effective, go for the smash.
And use protective gear. Whether you're cutting with power tools or smashing, use earplugs and safety glasses, sturdy boots and thick pants.
Some steel is not magnetic, and has roughly the same resale value per pound as aluminum. Of course, this "stainless steel" is very strong, and thus can be used to make items that are quite thin. The most common forms of stainless I see are kitchen sinks and cooking pots. Do not however assume that because it's shiny it's stainless, always use a magnet.
Here I'm especially welcoming of feedback from readers. Tin is quite valuable, and it's most commonly found in the form of pewter. Items made of pewter are not magnetic, typically quite heavy and either have no luster or are quick to lose it after being handled or exposed to water for any period of time. Pewter is most commonly seen in the form of very heavy bluish-gray figurines of dragons and wizards and such, as well as goblets and plates one might see sold at a Renaissance fair or given out to members of a winning softball team.
The problem I have is finding a market for pewter. Even the best scrap yard offered only die-cast price for a pound, even though tin - which makes up some 90 percent of the pewter - commands more like ten times that much. People who make figurines have to be careful not to buy cheap pewter, which contains lead and gives off especially nasty fumes when melted. I only buy pewter with hallmarks on the bottom that explicitly say "pewter", which I assume is a higher quality.
Since I first wrote this, I have been contacted by at least one buyer, who paid $4 per pound plus shipping. He used it to harden bullets he was forming for reloading gun cartridges, so that may be one outlet for your pewter as well.
"Tin" cans are not tin, in case you were wondering. They're very high quality steel, but in these modern times they contain little or no tin.
Does anyone know where I could sell quality pewter? I'm always looking for new markets to supply.
Copper is rather obvious stuff. It is very heavy, bends easily, and when scratched looks exactly like you would expect copper to look. It brings roughly half-again as much at th e scrap yard as brass, so it's well worth watching for. Keep in mind that you need to remove everything attached that is not copper. If there is even a small amount of brass, they will only pay you brass price. Do what they do. Break or cut off any part that can't be separated from attached brass, and throw it in with the brass.
Don't overlook the value of copper wire. If it's not magnetic, the copper in it has significant value, and the scrap yard will buy it with the insulation still on. I once put a large amount of copper wire in a 55-gallon drum and burned the insulation off. The smoke was green and pink and smelled green and pink. Let the scrapyard send it to a place where it can be burned in a plant with smoke scrubbers. Please.
I forget what it brings per pound, but it sure is heavy. The picture I have here is of two big game fishing sinkers (serious sinkers) that weigh 11 pounds between the two of them. Also look for electrical system ballasts, but make sure it says "no PCBs" on it, or you'll be the proud owner of something especially nasty.
Thanks to Catherine J, for asking me to elaborate on some of the comments I've made on scrapping out metal.
There is a learning curve in collecting metals for their scrap price. What you pay for them, gas and wear on your vehicle and the amount of time you put in all factor into your "cost of goods sold". Even after you get good at it, you may want to track your time and calculate the hourly wage. If you're in it for the money, and you're not making much, you might want to consider taking a second job instead.
Quality of life
Do you get enjoyment from tearing apart lawn chairs? Does the challenge of removing a handle from a skillet that has its nonstick coating scratched actually count as mental stimulation? Are you more likely to take a walk if it involves walking from one yard sale to another with a backpack full of metal items? Then to hell with the hourly wage. It's a hobby. It's exercise. It's a challenge.
Is your recycling activity actually a benefit to the planet, or are you engaging in the willful destruction of useful items? In the mantra "reduce, reuse, recycle", "reuse" comes before "recycle". Every time you recycle something, you commit a certain amount of energy to that purpose. Is it more valuable as is? What do you think are the odds of it being made into something even more useless? Ask yourself, "Is someone likely to buy this and use it?" If the answer is yes, leave it. I've done this many times.
Case in point: look at the copper fittings to the left. They have never been used - brand new. Highest quality copper. Heavy. Worth $4 a pound as scrap. But on closer inspection some of the price tags still attached say $5 (each). Don't recycle them. Sell them by the piece at your own yard sale. Donate them to an organization that does home rennovations.
It's an interesting mental exercise to just ask yourself the question.
Aluminum cookware works just fine for heating things up, but if the user cooks tomatoes or something else acidic in it, aluminum gets into their food and their bodies, so though someone might think that's a very nice big heavy pan, I recycle it even if I'm just breaking even.
Brass candle sticks are, you would think, something people would want to buy and use, however I've seen so many offered at yard sales for a dime that I can only conclude there is an oversupply, and the brass would be better melted down and put to another use.
As long as you're going to be asking yourself these questions, be prepared to answer them when asked by others. If you can't be comfortable explaining to others what you're doing, you probably haven't thought it through privately either.
Careful not to mangle your knuckles on the edges of jagged metal. Do not melt down aluminum or pewter at home for more compact storage (it generates bad fumes and you may well burn down your house). Some of the tools I use to break an cut metal could just as easily lop off one of my fingers.
Careful, now. Have fun.