How to Make The Metal Melter

In a previous video I used a modified Microwave Oven Transformer as an electrical metal melter. In this video you'll learn step by step how it was made, and what I'm using it for now. In a previous project, I found an old microwave in a dumpster and hacked it open to see what components I could salvage. This power transformer was one of my favorites, and got used in many other projects, like high voltage electrical arcs, making a homemade stick welder, and melting metal. In it's current condition, the transformer produces a deadly high voltage that's enough to kill a person on contact. But it won't melt metal. To do that, we have to modify the transformer by rewinding the coils. Looking at the sides of this transformer, you can see that these shallow welds are the only thing holding this together. I'm gonna use my bench vice to secure this in place with one end of the welded sides facing up, and try using a hacksaw to cut it open. This is a fairly weak weld, and a hacksaw will work, but a quick buzz with an angle grinder works a lot better. Now that that's ground off, a hammer and chisel can be used to crack the gap and pry the pieces apart. The rest can be removed by hand. With the bottom off, I've got access to the 3 coils of wire wrapped around the core. The top coil is the primary winding and I want to take very good care of that, so I've wrapped a cloth over my chisel to protect it as I pry up on the winding. It's in there pretty snug, but prying it slowly and gently from both sides gets it to the point where I can put the chisels down and pull it off by hand. These metal shunts can get knocked out now, and amazingly, this is the only form of current limiting this transformer has. The middle coil is junk, and it all comes out. Then to get the secondary coil off, I'm setting it with the coil resting on the jaws of my vise, and then hitting the middle of the core with a rubber hammer until the winding is free. This got pretty beat up, but that's ok because luckily I don't need it. A chisel works great for scraping off any excess paper and glue stuck on the sides, and now we've got ourselves a naked transformer core. You're looking at the "E" and "I" sections of the core, and at this point we're ready to reinstall our primary coil. This coil has about 100 turns of insulated copper wire, and needs to be replaced gently to avoid damaging it, or scraping the wires. That's why I'm using a rubber hammer so I can still get it in nice and tight. OK, it's looking like it's supposed to, so now we can add a secondary winding made from this thick 2 gauge copper cable. I was lucky and got this from a scrap pile my brother had at work. Looking inside, you can see it's made of stranded copper wire, insulated by a thick rubber coating. My brother got me a heavy duty copper lug, and crimped it in place on the end of the cable. Next, he added a little shrink-wrap to protect the connection, and hit it with a heat gun to shrink it down and finish it off. Alright, so with the cable bent in half, I can move it up next to the transformer and tuck it down into the gaps. The wire's so thick it's a pretty tight fit and probably couldn't be any bigger. I'm pulling one end of the cable back around the transformer, and I decided to switch the positions of these two so that it forms more of an ascending coil. Now I can press the other side into place, and the secondary coil is wrapped, as easy as that. The last step is to put this back together. I don't have anything to re-weld the seems I broke apart, so I'm going to try using this 2 part epoxy glue to see if I can make it work. Both the components get mixed equally, then I'll add the glue to all the exposed surfaces at the top here, and find a way to clamp this down. It turns out my bench vise has a gap wide enough to fit the entire assembly, and after double checking the alignment on the connection, I'll synch it up tight. I'm adding the leftover glue to the gaps on the edges and everything is looking as expected, so that can be left to set. Ok, it's 2 hours later, and our modification is complete! There's actually no physical connection between the two coils, yet this will pump out around 800 amps! To bench-test the device, I'm carefully hooking clips to both leads of the primary winding, and then adding power. Using my multimeter I'm showing just over 2 volts now, which is a lot lower than the 1000 volts this used to throw out. But instead of putting out 1 amp, now I'm getting closer 800!! What can you do with that many amps? I thought it would be fun to try melting some metal, which you can see this does easily. The metal melts because its not as conductive as copper wire. It acts like a resistor, and heats up from the electrical friction until it reaches its melting point. Or until the insulation on the lead wires melt and the system shorts out. Well not only was this a fun modification, but I found a practical application for it in making a spot welder like this one. The high current can be directed to fuse sheets of metal together at one precise location. Look for how to make that in another project. Well now you know how to build the metal melter. If you liked this video perhaps you'll like some of my others. Check them out at www.thekingofrandom.com

Channel: undefined

Views: 7,913,786

Rating: 4.903635 out of 5

Keywords: melter, hack, microwave, melt, MOT, transformer, molten, incandescent, amp, arc, current, mains, padlock, knife, screw, spark, glow, break, destroy, liquify, low, voltage, electricity, modify, scrap, recycle, shock, dangerous, lethal, gauge, wire, kipkay, metal, create, high, power, hi-power, gadget, household, science, crazy, educational, funny, education, hacker, most, viewed, weird, insane, entertain, entertainment, hobby, craft, the, king, of, random, thekingofrandom, thekingofrandom.com, .com, project, grant, thompson, 01032010814, Energy

Id: d5pGN6pqkyY

Length: 5min 13sec (313 seconds)

Published: Thu Dec 13 2012

Reddit Comments

[u/sellyourcomputer]

this seems hilariously dangerous. i think i'm going to make one.

[u/Dawn_Of_The_Dave]

He's not going to die of old age.

[u/Plasma_000]

The alliteration is strong with this one

[u/Dynamiklol]

Someone's going to die because of this.

[u/_Gizmo_]

I guess /r/ArtisanVideos is the new /r/DIY

[u/[deleted]]

Made one off his plans, can confirm fun, cannot confirm gaseous metal content of lungs.

[u/encaseme]

The confusion people have about amperage and voltage and "it's the amps that will kill you" is frustrating to read, so I'm going to try to explain it in an easy-to-understand (if a little wordy now that I'm looking at what I've written) way:

Yes, it's "the amps that will kill you" BUT amps will only flow in relation to the resistance of the object, and the voltage of the electricity pushing those amps. Because something CAN supply several hundred amps doesn't mean it WILL supply several hundred amps.

Take a car battery for example. Most car starter batteries are easily able to supply 500 amps or more (if not over a thousand). Yet, you can touch the two terminals of the battery with your hands without any issue at all; because the resistance of your body, and the relatively low voltage of the battery is such that only a minute amount of current will flow through your body.

Here's a way to think of it using the water-hose on the outside of your house as a representation. That hose is capable of flowing 20 gallons per minute (I'm making up the numbers, but it's just an example). If you tried to drink 20 gallons per minute it would kill you. However, you have a small spigot attached to the end of the hose that provides a small trickle of water that you can easily drink from. This small spigot provides a large resistance to the flow of water, so you get only a small amount of flow; despite the capability of the hose it is connected to. Electrical current is similar to the flow of water in this example, it won't flow if there is a large resistance no matter what the current-carrying capability of the system it's attached to is.

This microwave transformer in the video is similar to our water-hose example. There is a large amount of current capability, but if you attach it to something with a large resistance, that current simply won't flow, due to the laws of physics and nature. Nails and chunks of metal have a very low resistance, which is why they heat up as they do. You'll notice there is no current flowing through the air between the two outputs of the transformer; this is because air has a high resistance.

I haven't mentioned voltage yet in relation to our example. Voltage can be thought of as being like the water-pressure in our garden-hose example. Generally the pressure is set to something (lets say 50 psi) and you don't really change it. It's 50 psi pretty much no matter what the situation is, if water is flowing, or stopped. In our example if we wanted to force more water through our spigot, we would somehow have to increase the water pressure, which would indeed force more water through. We could increase the water pressure to a level where even the spigot cannot resist enough and we're back to it being enough water to kill you. Voltage can be thought of as working in a similar way.

In the microwave video, the output from the transformer is a quite low 2 volts. You could safely touch each output of the transformer with your bare hands and have no problems. The amperage across your body would be very close to zero, because 2 volts can only push so much current across the resistance of your body. Think of it as only having 2 PSI in your garden hose, trying to push water through a spigot, it's barely going to drip out; even though it's still the same garden hose that can provide 20 gallons per minute.

[u/Citizen_Snip]

That is fucking terrifying.

[u/warrendunlop]

Totally terrible title there the333zy — too tongue twisty. /s