Proper use of an oxygen acetylene torch

I’d like to explain a little bit about making an oxygen acetylene cut. I will give you some tips on some oxygen acetylene cutting and its use in the industry today. Some people use a plasma cutter for everything, but when you’re cutting set up for steel needs to be portable, the oxygen acetylene is best.

A couple of safety things we need first before we get started. Safety glasses never cut without some type of eye protection, hot sparks coming off the metal getting into your eyeball can really sting. The other thing is I always recommend wearing is gloves. I’ve seen people cut without them, but I’ve also seen people with big blisters and burns on their hands. The oxygen is in a big green or orange tank and can suddenly burn at 5500 to 5800 degrees so we’re very safety conscious. We’ll be using is a striker to light the flame. 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. And soapstone to be able to mark my line to cut. Frequently when you are using a torch to cut metal, you need to mark where you are going to cut. There are lots of ways to make a mark or a line that range from using a magic marker or sharpie, or just scratching the metal with an awl. The best way to make the marks you need is to use soapstone, which is the solid form of the same talc that is used in talcum powder. The handiest way to do this is to use pre-cut rectangular (127 x 12.7 x 4.8mm) prismatic pieces of talc, which are held in a special pen shaped device with a pocket clip that allows the talc to be firmly held and advanced as the talc wears down. These soap stone holders are available from many companies such as: Forney, Ally Tools, Hobart, Firepower, and Tech Team®  https://techteamproducts.com/. We happen to like Tech Team’s model 759 the best https://www.amazon.com/Soapstone-Retractable-Oxy-Acetylene-Tech-Team/dp/B07NGJ4MB1/ref=sr_1_3?keywords=tech+soapstone+holder&qid=1565098360&s=gateway&sr=8-3 because it has a durable zinc finish and a positive locking and advancing mechanism for the soap stone.

Of course, you also need soap stone, aka talc, to feed the holder as you wear out the soap stone. Those refills are available from several companies such as: Homee, Anchor, VasTools, Uniweld, Hobart, and also Tech Team®  https://techteamproducts.com/. We like Tech Team’s 757 36 pc. of soap stone https://www.amazon.com/Tech-Team-Soapstone-Machining-Surfaces/dp/B07JMFBFW3/ref=sr_1_44?crid=13B5M9FVHOOXU&keywords=soap+stone+holder+welding&qid=1565097627&s=gateway&sprefix=soap+stone%2Caps%2C128&sr=8-44 the best because it is high quality, bright white soap stone that leaves clear and easy to erase marks on almost any metal surface. Also, a chipping hammer, to chip off slag so there won’t be too much when I’m done, and a wire brush to clean the steel and a straight edge to work my cut. All of these items can be bought at Lowe’s, Home Depot, Allied Welding Supply, or online from Amazon.

When cutting, use a pair of shades for your eyes. I use the number 5 shade which are recommended for oxy acetylene cutting. We’ll use a darker shade for our welding, but for oxygen acetylene cutting number 5 is what’s recommended now. To set those up turn on the oxygen first. You open it all the way. There is a seal at the top of the valve that needs to be seated when it’s opened all the way just crack it until the pressure comes on and give it a quarter turn so we’ll be able to turn off the acetylene quickly in case of an emergency. The pressure for the oxygen that is going to cut a piece of 1/4 inch mild steel should be 40 PSI and run the acetylene between 5 and 8 PSI.

If you’re concerned with where the cut line is going to be, and you want to have a straight line and not a wavy, curvy line, especially when looking through the dark shades it’s very tough to tell exactly where you’re cutting. The line from a soapstone mark helps you be able to see it. Frequently when you are using a torch to cut metal, you need to mark where you are going to cut. There are lots of ways to make a mark or a line that range from using a magic marker or sharpie, or just scratching the metal with an awl. The best way to make the marks you need is to use soapstone, which is the solid form of the same talc that is used in talcum powder. The handiest way to do this is to use pre-cut rectangular (127 x 12.7 x 4.8mm) prismatic pieces of talc, which are held in a special pen shaped device with a pocket clip that allows the talc to be firmly held and advanced as the talc wears down. These soap stone holders are available from many companies such as: Forney, Ally Tools, Hobart, Firepower, and Tech Team®  https://techteamproducts.com/. We happen to like Tech Team’s model 759 the best https://www.amazon.com/Soapstone-Retractable-Oxy-Acetylene-Tech-Team/dp/B07NGJ4MB1/ref=sr_1_3?keywords=tech+soapstone+holder&qid=1565098360&s=gateway&sr=8-3 because it has a durable zinc finish and a positive locking and advancing mechanism for the soap stone.

Of course, you also need soap stone, aka talc, to feed the holder as you wear out the soap stone. Those refills are available from several companies such as: Homee, Anchor, VasTools, Uniweld, Hobart, and also Tech Team®  https://techteamproducts.com/. We like Tech Team’s 757 36 pc. of soap stone https://www.amazon.com/Tech-Team-Soapstone-Machining-Surfaces/dp/B07JMFBFW3/ref=sr_1_44?crid=13B5M9FVHOOXU&keywords=soap+stone+holder+welding&qid=1565097627&s=gateway&sprefix=soap+stone%2Caps%2C128&sr=8-44 the best because it is high quality, bright white soap stone that leaves clear and easy to erase marks on almost any metal surface.

Now we’re getting ready to cut. For the torch we use a Victor cutting torch, it’s good for 1/4 inch to 3/4 inch steel. You can use a Harris, Smith, or Forney torch as they all have excellent quality. There are 3 knobs on this torch, the oxygen is going to stay open all the time if we convert this torch over for welding. If we use that valve to adjusted for cutting, it stays fully open and then just adjust the acetylene. Now give the acetylene a little bit of a turn, about a quarter turn and light it with the striker and get the flame burning pretty good. At this point if you don’t have the Welder’s Handbook, do a Hey Siri or Hey Alexa search for the correct pressures to use with the tip and thickness of the steel you are cutting. 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.

Now open the oxygen slowly until the tip goes away, you’ll see the six points get sharp and clear. To get this right we need to set our oxygen lower so we see no feather. What I’m looking for in a good oxygen acetylene cut is that we blow off most the slag. There shouldn’t be a whole lot left. If you’ve got bacon dripping slag, you’ve probably gone too slow.

There’s six little holes around the outer edge that creates a preheat flame. The hole in the center is the oxygen cutting blast. What we do is use the preheat flame to heat the metal, heat it up to a cherry red point then when you hit the oxygen lever that causes the rapid oxidation of the metal. We’re actually burning the steel through to produce a clean cut, a straight cut, if you do it right. A little bit of slag may have to be chipped off or cleaned up with a grinder and you’re done.

Next, I’d like to talk about a little bit heavier cut with 1 inch steel for a project that I have in the shop so I turn up the oxygen to about the max. Normally we run the oxygen between 20 and 40 PSI, so I’m gonna run it all the way up to 40 PSI. If I push it any harder, I’ll get a heavier blast through the metal then we want to make sure that we have enough heat to carry ourselves all the way through the metal. For example, if I’m cutting through a heavy structural I beam, or cutting high pressure large diameter steel pipes.

The preheat will start on the edge of metal and get cherry red then when I hit the oxygen lever, we’re going to blast the metal through. One inch metal is a little thicker than this torch is set up for. So I got to do it without getting too much slag. I did things differently here; I used the straight edge. When you’re making a straight cut on metal a straight edge can be used to make sure you get a nice straight line. I’m not going to pick up the hot piece of metal because that’s a good way to ruin your day.