Cutting with Fire: DIY Metal-Cutting with an Oxygen Torch

This year, I've been trying out all kinds of handheld torches, using several types of fuel. The tool geek in me really wanted to challenge myself and move up to something even more serious. Luckily, I got my hands on a

Cutting, Welding, and Brazing Torch Kit , the big, hot Mamma of the Bernzomatic line.

I've done recent torch projects with butane (up to 3,150° F), projects with propane   (up to 3,600° F), and projects with hotter burning MAP-Pro (up to 3,730°).

The Bernzomatic OX2550KC, is the next step up. It uses a dual-gas fuel setup; burning both MAP-Pro and pure Oxygen. This compact, fire-breathing beast can produce a flame up to an incredible 5,300° F!  It's not even a commercial tool; it's something you can pick up for yourself at a hardware store or home center.

I wanted to try cutting metal with fire. I'd never done anything like it. I think this torch in cutting mode is probably best suited for metal stock, perhaps around 1/8" thick or so. So, naturally, I decided to push well past that on my very first task. I'd been wanting to remove an old, bent fence hinge from our block wall. It was there when we bought our home and has always been an eyesore. The trick would be to cut it off behind the face of the block, so I could patch over it. A reciprocating saw would be difficult to use in that spot. I'd bend the heck out of some blades, chip the wall up, and rattle the heck out of my arms.

It's time to go, Mr. Bent Hinge Pin

This torch doesn't work like a standard handheld torch, it takes a bit of fiddling to get the hang of it, but it's incredible when you do. After a little practice, I was able to perform the fine dance of easing more and more gas into the flame, making it hotter and hotter, a blue/white blade of flame.

The Bernzomatic OX2550KC Cutting, Welding, and Brazing Torch Kit

The Bernzomatic OX2550KC Cutting, Welding, and Brazing Torch Kit This is a hose style tool, with fuel cylinders placed remotely, away from the torch head. Starting the torch requires opening the MAP-Pro valve, ever so slightly and using a handheld sparker to ignite it. 

Come on Baby, Light my fire.
— Jim Morrison

It takes a different approach, too much gas flow and the flame will go out with a quick blast and a "pop!" 

Since I'm used to using a standard, handheld torch which can be instantly lit with a hearty blast of flame, it took me a several tries to figure out that I needed to use a very light touch. The MAP-Pro fueled flame needed to be quiet and soft, waving gently like a stick pulled from a camp fire. I learned to ease the MAP-Pro flow down even more, until the base of the flame barely touched the torch nozzle.

Isn't it soft and cuddly?

Next came the oxygen. Its valve appears to be finely threaded, because you can turn it quite a bit before the oxygen gets flowing. It's great for controlling the release of a very small amount of gas and easing it up slowly. Too much oxygen, too quick, and "pop" out goes the light. In that case, everything has to be shut off to safely start again.

Speaking of safety, you'll note I stepped up my gear a couple notches for this project. First,since there would potentially be sparks and molten metal, I wore long pants and shirt sleeves (in Arizona even!). Beefy, long-wristed welding gloves would protect my hands if anything spattered. I capped my natty ensemble off with some Mad Max eye-protection, exchanging my normal safety glasses for a shaded, welding mono-goggle. I wouldn't take any chances with my already crappy eyes and a blinding, white-hot flame.

Fire, when you can't see the whites of my eyes.

As I slowly eased more oxygen into the flame, it snapped from the slowly waving, orange flame, to a crisp jet of blue-white fury. To cut with this rascal, I had to get it as hot as possible. It took a few tries, but I got the hang of dancing my hand between the MAP-Pro and Oxygen valves, until I got a real tight blast going. 

The perfect flame of awesomeness

With my finely-tuned fire-knife ready, I eased the absolute hottest point up to the metal hinge. The tip of the innermost cone of blue flame was the sweet spot. It was a 1/4" of legendary dragon-fire.

I slowly eased the cutting tip of flame back and forth, ever so slightly, watching the metal turn red-hot. Soon, the surface was liquified and starting to flow. I could move a gelatinous blob of molten metal around with the tip of the flame. 

I was really getting going when the flame died out. Getting the initial feel for working the tool sucked down quite a bit of oxygen. I'd run out, just when I was having fun. I ran out to the hardware store and grabbed another, which was perfect, because they had just finished making the first batch of popcorn for the day.

The second time, with the learning curve behind me. I got my flame ripping in no time. I was once again in the molten metal business.

"Hot"

As I cut, it seemed like the liquid metal helped accelerate the process, it kept the hinge piece stay glowing hot. 

The camera, just doesn't do it justice. Even through the shaded goggles, it looked incredible, like a movie scene from a steel mill. It was too fun to be work.

Hotter

I tapped on the piece few times with a pair of pliers and could easily bend it. A couple flaming minutes later, I grabbed ahold and snapped it off without effort.

Hottest

Although the red glow faded very quickly, the piece was still dangerously hot. I could feel the heat radiating from it on my weekend-stubble chin.  Even after cooling on the ground for several minutes, it still scorched the board I set it on like a wood burning iron.

It was a shame I was done. It was just too much fun.

Naturally, the kid in me decided I really needed to push the remaining bit of metal back, just a little deeper into the block face, because,... molten metal!

I sparked up some fire again. I really had the hang of lighting the torch by this point, quickly getting the flame into good cutting shape. With the flame concentrated in a recessed hole in the block, it created an oven of incredible heat, liquefying the metal in seconds. 

The Bernzomatic Cutting, Welding, and Brazing Torch Kit really is a cool tool. I pushed it hard on my first foray, not only cutting, but cutting a really thick piece of metal. I think I may do a more crafty-dude project with thinner metal at some point. I'm also looking forward to using it to try brazing, basically a big-kid version of soldering, to weld metal together. 

What do you think? Ready to try this powerhouse of flame?

This is a sponsored post. I am a proud to be a Bernzomatic Torch Bearer, though all opinions expressed are 100% my own. I won't recommend products I don't believe in.

The Torch Bearers are a group of tradespeople, DIYers, culinarians, adventurers and artists brought together to create projects using Bernzomatic torches and share their knowledge and ideas with you. Check them out here and get inspired to create with fire.

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