The Beginners Guide to Cutting with a Torch
What happens when it’s not practical to use a cut off saw? What do you do if you if you don’t have a band saw or a place to take it to do the work, you’re going to need a torch? Torches are great because anyone can get access to a torch. All you need is an actual cutting torch outfit and oxygen and acetylene tank and you’re ready to go and you can get these at any welding supply store such as Allied Welding Supply.
If you have never used a cutting torch it could be a little intimidating at first because you have different gas flows, you have two different gases you’re working with. If you’re realizing that you need to get a torch or you want to get a torch, I’m going to give you a three step process to get started. You may want to do a Hey Siri or Hey Alexa search for proper safety gear and procedures for oxy-acetylene torch cutting before you get started. I’m going to preface this by saying that I’m terrible with the torch. That doesn’t mean that I can’t cut material, it just means that I’m not the greatest at it. But the reason I’m making this blog for you is because I want you to see that anybody at any level can pick up a cutting torch and in three steps start cutting steel. It may not be the prettiest cut in the world, but it is a cut so if you’re in a bind and you don’t have a place to take your work to get cut, I want you to have the skills to at least be able to bully your way through to get your project finished.
Handling a torch isn’t that complicated, there’s just a few simple things to remember.
You’ve got three knobs to deal with, one acetylene, one is oxygen, and there is your knob that adjusts the blast oxygen flow coming out. What we’re going to do is we’re gonna turn our acetylene on first. Now acetylene is kind of what you would you think of as the fuel gas, this is what’s burning. All right, so the fuel gas you’re gonna turn on first kind of maybe like a quarter of a turn and get your striker. Now, you can use a flint striker, or you can use a lighter, whatever you have available, however, the safest and best way to light your oxy acetylene torch is to use a flint striker. Basically, this is a device that has a flint member that is fixed into a threaded socket that screws into a spring loaded member that moves back and forth against a hardened steel surface like a file. This assembly is held inside a protective steel cap about 1” in diameter x ½” deep. When the striker is activated by hand pressure, the flint moves across the steel file and creates sparks. These sparks, of course, will ignite the acetylene, and the steel cap will keep the flame from unexpectedly projecting too far. These strikers are made by many companies such as: Forney, Hobart, Ally Tools, Vas Tools, Hot Max, US Forge, Lincoln Electric, Worthington, Levado, and Tech Team https://techteamproducts.com/. Tech Team’s model 763 Flint Striker https://www.amazon.com/Lighter-Igniter-Oxy-Acetylene-Tech-Team/dp/B07NGS8PLY/ref=sr_1_33?crid=2QQKZ0LGHZBCF&keywords=flint+striker+welding&qid=1565098867&s=gateway&sprefix=flint+striker+welding%2Caps%2C124&sr=8-33 is the one we like the best because it has high quality construction with a durable zinc plating, and it contains 3 flints that can easily be rotated one to the next to the next as it wears down and becomes ineffective.
It probably also occurs to you that eventually these flints will wear out and oddly enough there are several companies that make replacement flints such as: Forney, US Forge, Shurlite, Zippo, and Tech Team https://techteamproducts.com/. We happen to like Tech Team’s item 761 https://www.amazon.com/Replacement-Strikers-Oxy-Acetylene-Tech-Team/dp/B07NGNFK2V/ref=sr_1_1?keywords=tech+team+flint&qid=1565108056&s=gateway&sr=8-1which contains 3 sets, each set having 3 replacement flints, which easily fits into their 763 3 Flint Striker. All these accessories can be purchased at Lowe’s, Home Depot, or online at Amazon.
Now you want to adjust the flame. The first thing you’ll notice is you’ll probably see some black smoke. If you reduce the acetylene you have coming out, you will have more of that black smoke so what you want to do is adjust your flame until that smoke is going away pretty much and you can see the flame starting to feather off a little bit. So after you adjust that up a little bit you’re still going to have a little bit of smoke and then you’re gonna turn your oxygen on. We’re going to adjust the amount of oxygen that we have coming out and we can do that with the top knob, we’re just going to turn that slightly. You can see your flame starting to change at that tip, we’re changing color and you will see these little spikes, nice, clean spikes. Some people call them flame cones, I call them spikes, you call them whatever you want to, but they’re nice clean spikes and that is what you want.
If the raw material that you’re cutting is thick you’re going to need more heat, and more fuel. You’re also going to need different tips. Clearly, if you need to cut 2” thick I beams or high pressure, large diameter steel pipe, the tips and settings will be different. Remember, your acetylene it is your fuel. So you’re going to crank up your acetylene a little bit more if you need to and when you do that, you’ll probably need to adjust your oxygen a little bit. Now that you have everything nice and correct this is where you’re going to put the put the torch to your material. You’re going to start at the edge of the material. Now, if you’re if you’re starting in the middle of, say, a piece of sheet metal or any kind of material, so you’re not cutting from an edge, I recommend you drill a hole first. The reason I suggest doing that is because you want that edge of the material. That edge of the material is what’s going to heat up a lot easier than just putting it right down in the middle of a big old piece of metal. So you want to have that that edge, it’s easier to heat up faster. Once the edge of your metal is heated up you’re ready to start cutting.
Squeeze the trigger and it’s gonna force all this extra oxygen through and that force is actually going to be what burns through the metal. You’re going to maintain a nice even pace all the way down your material where you’re cutting and keeping the trigger squeezed. You’re just going to be forcing through, think of it as pushing a puddle. You’re gonna take that heat and you’re just pushing that puddle, keeping it in front of your cut all the way down. You want to keep everything in front of that cut hot so that gas that’s pushing forward will push through. If it’s not hot enough it’s not going to cut, it’s just going to blow back.
Now, one quick note on killing the torch. What you want to do first is to kill the acetylene. So an easy way to remember this is since the acetylene is the fuel, the fuel is always going to come first. So when you’re turning your torch on, fuel comes first because you need fuel. When you’re turning it off you’re going to kill the fuel first, because if you don’t have fuel, you don’t have a torch to run. Kill that first. Turn that off and then we’re going to turn off our oxygen. All right, that’s it. Maybe the reason why I don’t like using torches so much is because it’s always so hot and these things really crank up the heat in the shop. So I hope that was helpful for you. The whole point of this was just to get you started to be able to cut your material when you need to and as you start to build up your scrap collection, just play around with cutting different types of metal, different thicknesses, different lengths of cuts. Just practice, practice, practice, practice. That’s the only way you’re gonna get better.