How to Make The Metal Melter

How to Make The Metal Melter

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

100 thoughts on “How to Make The Metal Melter

  1. Find the smile ? if you do find it like it and reply


  2. You are probably wondering how this works, and how it turns a high voltage into a high current, it works like this; it's elektrostatic induction, when you bring a object that is loaded with a current close to another object that isn't loaded.
    Then it will create induction, it works the same with an induction furnace, high current in 1 coil, the low current in your pan.
    You can prevent the wirers from melting by placing a heatsink or a fuse, or also a monolitic switch, it will limit your current.

  3. You should reverse the primary and secondary coil to get insanely high voltages. Maybe an unmodified microwave transformer would really only get you around 2000 V+, but the one that you changed could probably yield around 10,000 V+ 🙂

  4. "Jacobs Ladder" (50's sci-fi effect): oil furnace transformer (microwaves no longer use monster transformers); two coat hanger wires, in "V" form mounted on block of wood.

  5. I have some questions, why isnt the big wire connected to the coil? why does it create an high amperage and not high voltage? and what does the Metal thing around it (from the microwave) do?

  6. I think I will just use my cutting torches or my 220 volt stick welder. And as far as my old microwave ovens they will just go to the scrap yard!

  7. Ive tried this 3 times now and every one has worked but the make to loudest unbearable buzzing noise so i can never really use them. Any ideas to fix this?

  8. He expect us to go and buy/get 4' of 2 gauge copper wire, at 2$ a foot!?!
    that is not 2 gauge wire, that is 0 gauge, still expensive.

  9. Imagine if someone made a battlebot with this as the weapon and just went up to the other robot and touched the two points and just watched as the other robot just started smoking and stopped moving, that would be great

  10. I have every thing needed to do this but the primary coil does not come out that easily
    Edit: I literally bought the same gloves, cloth, vise, hammer, and angel grinder and the primary coil still won't come off

  11. sir can you please clear my certain doubts as i am making this. 1.what is the input voltage and current and how much input watt please sir reply

  12. I have a scrap microwave in my house, but the closest thing that I could find to a M.O.T was a capacitor. Would this work as well?

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