13 Backyard Science Experiments From The ’60s That Would Definitely Be Illegal Today

Growing up in the ’60s meant a kind of wild freedom—especially when it came to science. Back then, curiosity wasn’t confined by today’s safety guidelines or parental panic.

Kids like me could order real chemicals through the mail, mix questionable compounds in the garage, and even handle radioactive materials without anyone batting an eye. The backyard was our laboratory, and our imaginations were the only limit.

Science kits of the era came packed with substances that would make modern parents (and probably the FDA) faint—things like mercury, potassium nitrate, and uranium ore. But it wasn’t reckless; it was hands-on learning, fueled by genuine excitement and a belief in the future.

It was messy, dangerous, and thrilling—and it sparked a lifelong love of discovery in a generation raised on experimentation.

1. Mercury Playground Adventures

Silver liquid magic danced across my palm the day Dad brought home a vial of mercury from his laboratory. The heavy metal pooled and separated in fascinating ways, and we’d spend hours playing with it on the kitchen table, watching it split and rejoin like some alien creature.

Sometimes we’d dip pennies in it, coating them in silver until they looked like dimes. The neighborhood kids would gather around as I showed off my “magical” metal that could slip through the tiniest cracks yet remain perfectly whole.

Nobody warned us about mercury vapor or absorption through the skin. We handled it bare-handed, occasionally spilling drops that would roll under furniture, leaving toxic little time bombs throughout the house that would trigger a hazmat response today.

2. Backyard Chemical Cauldrons

Chemistry sets in the ’60s were no joke! Mine came with real chemicals including potassium permanganate, ammonium nitrate, and enough acids to dissolve small objects. I’d mix these dangerous compounds in the driveway, creating bubbling, smoking reactions that sometimes changed color or burst into flames.

My greatest triumph was creating a miniature volcano that not only erupted but also shot green flames three feet high! The neighborhood kids cheered while my mother watched nervously from the kitchen window, somehow trusting that I wouldn’t poison the neighborhood or blow myself up.

The instruction booklet even suggested experiments that produced chlorine gas and other toxic fumes with only a casual warning to “work in a well-ventilated area.” Today’s chemistry sets contain little more than baking soda and food coloring by comparison.

3. Homemade Rocket Fuel Bonanzas

My buddy Tommy and I spent countless summer afternoons mixing potassium nitrate (saltpeter) with sugar to create our own rocket fuel. The white crystals and sugar would melt together in Mom’s saucepan, creating a bubbling caramel-colored goop that hardened into powerful propellant.

We’d pack this concoction into paper tubes reinforced with electrical tape, add a fuse from a firecracker, and stand back as our creations zoomed skyward or, more often, exploded spectacularly. No permits, no safety equipment, no adult supervision required!

One rocket sailed so high it disappeared completely, likely landing in old Mrs. Pemberton’s garden three blocks away. Today, this homemade explosive would land parents in hot water faster than you can say “potential felony charge.”

4. Radioactive Rock Collections

For my twelfth birthday, Uncle Frank gave me the most coveted science gift of all – a real uranium ore sample for my rock collection! The gray-green rock came with a simple cardboard box and a special sticker warning about radioactivity, which only made it cooler.

I’d show it off during show-and-tell, passing it around the classroom while explaining how my Geiger counter (another amazing gift) would click faster when held nearby. The science teacher actually encouraged this, explaining how radiation worked while we all handled the sample.

Mail-order uranium samples were perfectly legal and marketed specifically to children through the back pages of popular science magazines. No background checks, no special handling requirements – just pop it in an envelope and send it to any curious kid with pocket money and an interest in nuclear science!

5. Carbide Cannon Catastrophes

Pop! Bang! BOOM! The carbide cannon was the crown jewel of my backyard arsenal. This miniature artillery piece used calcium carbide – the same chemical used in mining lamps – which produced explosive acetylene gas when mixed with water.

Loading was a delicate operation: drop a pebble-sized chunk of carbide into the chamber, add a few drops of water, quickly close the breech, and aim. After a few seconds, the gas would build up enough pressure that a spark from the flint ignition would send the cannon’s report echoing through the neighborhood.

My friends and I would wage epic battles, shooting the cannons at each other across the yard. Once, I accidentally aimed too low and blew a softball-sized hole in my mother’s prized rosebush. These days, possessing such a device might get a child expelled or worse!

6. Lead Casting Workshops

Rainy Saturdays meant it was time to melt lead in the garage! Dad taught me how to salvage fishing weights, old pipes, and wheel balancing weights, then melt them down in a cast iron pot over our camp stove. The silvery metal would pool and shimmer, releasing fascinating (and now I know, toxic) fumes throughout our poorly ventilated workspace.

We crafted toy soldiers, car replicas, and once, an entire miniature chess set using plaster of Paris molds. The molten metal sizzled satisfyingly when poured, occasionally spitting dangerous droplets that left tiny burn marks on my arms.

Sometimes neighborhood kids would bring their collections of lead items to contribute to our casting sessions. We’d handle the finished pieces while still warm, admiring our handiwork with lead-coated fingers before heading in for lunch, never washing our hands first!

7. DIY Tesla Coil Shockers

Nothing impressed the neighborhood kids like my homemade Tesla coil! Following plans from a dusty electronics magazine, Dad helped me wind copper wire around PVC pipe, connect capacitors salvaged from old radios, and hook up a dangerous-looking spark gap made from door hinges.

When powered up, this contraption produced foot-long electrical arcs that could light fluorescent tubes held in mid-air. We’d take turns holding metal objects near it to draw spectacular purple lightning bolts that tingled and sometimes burned our fingers. The crowning achievement was using it to create a Jacob’s Ladder – two wires with electricity climbing between them like something from a Frankenstein movie.

The whole setup was plugged directly into the wall socket with no safety cutoff switch or isolation transformer. One wrong move could have meant a direct connection to household current through our curious young bodies!

8. Gunpowder Manufacturing Plant

My grandfather, a former military man, saw nothing wrong with teaching me to make gunpowder at age 13. “Every boy should understand explosives,” he’d say as we carefully measured potassium nitrate, charcoal, and sulfur into a coffee grinder dedicated to this terrifying hobby.

We’d grind the components separately, then mix them together with a wooden spoon on a sheet of paper. The resulting black powder would be tested by creating small piles and lighting them with a long matchstick. The successful batches would whoosh into flame with a satisfying flash.

The real fun came when we packed the powder into cardboard tubes to make our own fireworks or used it to launch projectiles from homemade cannons. Grandpa’s only safety rule was “keep your fingers crossed and stand back” – a far cry from today’s controlled explosives regulations!

9. Chlorine Gas Chemistry Lessons

My chemistry teacher, Mr. Hoffman, had a flair for the dramatic that would get him fired today. His favorite demonstration involved mixing household bleach with vinegar in an enclosed container with a small opening, creating chlorine gas that he’d waft toward students to give us a “small sample” of chemical warfare.

Inspired by his cavalier approach, I recreated this experiment in our backyard shed, mixing various cleaning products to see what reactions I could produce. The resulting gases sometimes made me dizzy or burned my eyes and lungs, but I considered these symptoms part of the scientific experience.

Once, I accidentally created enough chlorine gas to kill all the plants near my “laboratory” and turn a portion of our aluminum siding a strange color. Mom merely suggested I “take that stinky business further from the house” rather than shutting down my toxic gas production entirely!

10. Thermite Welding Demonstrations

The day my science teacher demonstrated thermite remains burned in my memory like the reaction itself. Mr. Peterson mixed aluminum powder with iron oxide (rust) in a flowerpot, stuck a magnesium strip in it, and lit it with a blowtorch right on the school playground!

The resulting reaction was blindingly bright and hot enough to melt through metal. Inspired, I convinced my parents to order the components through a science supply catalog. Soon, my friends and I were creating our own thermite in the backyard, melting holes through old metal garbage can lids and once, accidentally, through Dad’s workbench.

We’d stand mere feet away from reactions reaching thousands of degrees, protected by nothing more than sunglasses. The molten iron would drip like liquid fire, leaving permanent scorch marks on our concrete patio – battle scars from the golden age of unregulated science exploration.

11. X-Ray Shoe Fitters

Shopping for school shoes in the ’60s came with a special treat – the magical X-ray machine that let you see your bones! I’d wiggle my toes inside the new loafers while peering through the viewfinder at the glowing green skeleton feet beneath.

Sometimes the shoe salesman would let us play with the machine even when we weren’t buying anything. My friends and I would take turns X-raying various items: loose change, a pocket watch, and once, a frog in a jar that Tommy had caught that morning.

Nobody worried about radiation exposure from these fluoroscopes, despite the fact that they were bombarding our growing feet with X-rays. Parents would encourage multiple viewings to ensure a “perfect fit,” completely unaware that these machines were delivering radiation doses that would horrify modern health physicists. Some stores even had multiple machines for busy shopping days!

12. Asbestos Handling Arts & Crafts

“The miracle mineral!” That’s what our science textbook called asbestos, and my school encouraged hands-on exploration of this wonderful substance. We’d pass around raw asbestos fibers, marveling at how they could be pulled apart into soft, fluffy strands perfect for arts and crafts projects.

My crowning achievement was my Christmas project – a snow scene diorama where I used asbestos as snow, crushing and fluffing it with my bare hands to create the perfect winter wonderland. The teacher praised my creativity and even displayed it in the school hallway for months!

At home, Dad would let me help him install asbestos insulation around pipes in our basement. I’d cut the wrapping material, sending fibers floating through the air that we’d breathe in without a second thought. The same material now requires hazmat teams and specialized removal procedures!

13. Homemade Electroplating Setups

My bedroom doubled as an electroplating laboratory after I discovered how to coat objects in copper, silver, and nickel using household batteries and chemicals ordered through the mail. The setup was gloriously dangerous – jars of acid-based solutions connected to batteries with exposed wires, all balanced precariously on my wooden desk.

I’d dip metal objects into cyanide-based solutions (yes, actual cyanide compounds sold to children!) to coat them with a thin layer of precious metal. My specialty was “silver-plating” pennies to make them look like dimes – a trick that walked the line of counterfeiting but was overlooked as youthful experimentation.

The chemicals would occasionally spill, burning holes in my carpet and once, when mixed incorrectly, produced a gas that turned my white curtains a sickly yellow color. Mom’s only concern was whether the stains would come out in the wash!