Using A Cutting Torch

it wasn't long ago that a cutting torch was almost the only way to cut metal in most fabrication shops now since then with the advent of plasma cutters and you know carborundum wheels and the band saws that most people can afford there are other ways to cut metal but a cutting torch is perhaps the most versatile of all the tools that exist for the purpose of cutting metal i want to talk about cutting torches what they are how they work and how to use them but i want to tell you right now this is an entry-level sort of description of the process and the the tool there is a lot more that can be said about cutting torches and cutting metal than i know so what i'm going to share with you is what i know about how to use it for general purpose in a fabrication shop safely and hopefully effectively first thing to talk about is the bottles because when you're understanding the cut and torch you have to understand the risks and the benefits of that these bottles bring to the table let's talk about the oxygen first these are these bottles are heavy i mean they are heavy because they're withstanding a lot of pressure that means you do not ever want it to be penetrated if it's shot you got a problem but the more likely thing is you don't want it to tip over if this tipped over and that valve hit the edge of that table and broke the neck off this bottle visualize a 200-pound balloon being let go it will launch there are horrifying videos on youtube about what it looks like when an oxygen bottle gets the neck knocked off of it takes a long time to stop and it will go through anything i mean anything before it does come to a stop so item one protect the bottles from falling over and if you're transporting them make sure that the valve is off and the safety cap is on the acetylene bottle not near as much pressure but it it contains gas that is flammable enough and there's enough of it to blow up just about anything that it leaked into so you have to be sure all the time that the bottle's off and if it is off you're always monitoring all of the all of the um joints all of the connections for leaks if you smell acetylene which smells different than natural gas it doesn't have to be odorized like natural gas because it has its own distinctive scent shut things down because you do not want acetylene leaking into your workspace while you are doing all the other things that happen in a fabrication shop so control leaks and if you're transporting this do not put it in an enclosed environment do not put it in your trunk and put the safety cap on it every time in my shop these bottles live on the cart and that's great about ninety nine percent of the time because i always make sure that the cart is leaning up against or is secured to something that is bulletproof and nothing is ever going to make it tip over for any reason so here's two things the valves are always off when you're not using them so when you walk up to the tank to use it you turn the oxygen on all the oil not all the way but three or four turns you don't back it all the way out to the end of the threads but you turn it on and then you turn your regulator up until the valve with the big numbers shows about 20 pounds now the gauge with the small numbers is indicating what percent full the bottle is it gives you an idea of how much oxygen you got left but the the gauge with the large numbers that responds to turning in the regulator is telling you how many pounds of pressure you're getting out of your oxygen line and for general use you want 20. now the acetylene bottle is a completely different animal i don't turn it on all the way i turn it on about a quarter of a turn maybe a half and the pressure is turned up at the regulator until it reads about seven psi for normal cutting you will learn to adjust these pressures up and down a little bit depending on what you're doing with the torch but 20 on the oxygen seven on the acetylene is a good place to start now once you've set the pressures with the the gas in the line static you may want to check them again once you're actually lighting the torch because with the gas flowing you may need to turn the regulator up just a little higher to sustain the pressure that you had them set at when you set your your setup originally now that varies you know regulator by regulator and torch by torch but in general once you're burning go back and check and make sure you've got 20 and seven this is a cutting torch consists of a torch body and the cutting tip there are two valves to the torch body and two valves to the cutting tip let's go to the cutting torch itself and the lighting sequence we've got four valves three gate valves i think and a squeeze valve the first thing you do is turn this oxygen gate valve the one closest to the bottle on essentially all the way several turns wide open the next thing you do is crack the acetylene just a little now we have some acetylene coming out of the tip and no oxygen yet that's an acetylene flame with no added oxygen except what is getting from the air this oxygen valve is open and so now we crack this oxygen valve just a little and open it until that white feather disappears see that that is pretty much a neutral flame we'll talk about what that means in a minute but the last step in lighting this torch is to squeeze this valve and then open the oxygen until the last of those white feathers is gone that's how you light your torch to shut it off is the reverse sequence you close this valve there's an acetylene flame with no added oxygen and then shut off the acetylene or fuel now let me show you what happens when you do not shut it off in that sequence remember this is on i crack this valve it's lit i turn that on i hit the lever i give it a little more and if i shut off the acetylene did you hear that little snick sometimes it's a pop sometimes it will pop when you shut the fuel off first and that creates some pressure and pushes soot back up into the tip and it's not good so you always just reverse the sequence oxygen off first acetylene off second i'm going to give you a little more sort of global information on cutting itself and in the future time will give you more specifics on different metals and pressures but for now here's what you need to know maximum temperature is at the tips of those little six white cones there are six little bitty holes around the big hole that's in the middle and your maximum temperature is at the tips of those cones not pushing those cones into the work not holding back a half an inch but at the tips you tip the torch so it's pointing in the direction that you're traveling but you do not begin to move until you have a molten pool that you can see on the surface now you got to think about what's happening you have six little bitty independent jets around the circumference each of them super hot each of them almost touching the metal as each of those little jets begins to melt its own little spot of of the steel in just a matter of seconds or less those spots grow until the whole area about the size or the tip of the torch is suddenly bright yellow and liquid that's the moment that you squeeze the lever and begin to move slowly forward as soon as that molten pool has blown through the bottom of the piece you're cutting you don't begin to move until the entire area is molten the lever is hit and you can see probably through your peripheral vision or perhaps looking down into the top of the pool that the jet of oxygen has actually pushed the molten steel straight through the piece and out the bottom at that point it's just moved steadily and slowly and smoothly forward maintaining the right distance above the work maintaining the right angle relative to the work and moving forward at the right speed there's nothing to it cutting steel with a cutting torch is one place that you darn sure better be protecting your eyes i mean at the moment of hitting that pool with the blast of oxygen molten steel can come straight back up into your face so your eyes have to be protected now the ultraviolet radiation that comes from a cutting torch is not near as intense and in fact i would almost argue that it there is none but i won't stake out that ground but it's not the same as arc welding so it's not going to give you sunburns it'll just give you blisters i mean if the steel gets on you and it's not going to blind you like an arc weld will if you stare at it but you can see what you're doing better if you have some sort of a some sort of a filter just helps your ability to keep track of what you're doing if it's not too dark now i can use this i mean it doesn't get i mean that's going to protect me right but it's not going to make it easier to see the work if you have a speed glass type of welding helmet with a grind setting so that it's not flashing full dark put it on put it on grind it's slightly tinted you can see well you're well protected so bottom line is you know you're a grown-up let's assume you're a grown-up you better take responsibility for your vision when you're using a cutting torch because it's one of those tools in the shop that can easily and permanently put out an eye there's a world of information that i haven't dumped on you yet a lot of it i don't even have that the fuel line is left-hand threads that you never oil the regulators and on and on and on tip sizes and cleaning but we're not worried about that now because it's time for you to pick up that torch and cut some steel it's the way you're going to learn to do this and the learning curve is steep for a short period of time and then gradual for the rest of your life so if you just pick up that torch and uh start cutting some metal start getting some little burns on your hands start thinking about what's happening as you're traveling along and how you can keep the distance uniform as you move forward before you know it you'll have no trouble cutting out shapes making parts cutting the bolt heads off that are stuck just doing a wide variety of things that can only be done in most shops with a cutting torch [Music] now when a saw stops cutting smoothly it usually needs to be sharpened and when a cutting torch stops cutting smoothly you might need to clean out the jets of the torch tip itself get a tip cleaner and very carefully remove the soot and the dirt and the bits of melted metal that build up inside those tiny holes using these tiny files now don't make the holes bigger don't force a file in there that just doesn't want to go because you want to just clean out the holes don't increase the diameter and try to not let the filings and bits of debris fall back into the tip now just like everything else these tips are going to wear out so if you're new to this game and you're working with an old used torch a new tip might be a big help you know it was difficult for us to get a nice clean shot of the actual fire itself the cones of the neutral flame and the acetylene feather that i mentioned when we were lighting the torch and i didn't even bring up in this video the difference between a carburizing flame and an oxidizing flame we'll save that for another video so for now you're gonna see what i mean about the different parts of the flame when you light it it's the little cones that indicate neutral combustion they're in the deepest part of the flame one at each of the six jets around the circumference of the torch they're right up against the tip itself and they are actually white in color when you increase and decrease the oxygen you're going to see them change shape right in front of you and the torch is ready to cut the moment that the acetylene feather disappears as you are increasing the oxygen flow through the lever valve don't sweat this you're gonna know it when you see it you're gonna figure this out thanks for watching and keep up the good work [Music] so [Music] you

Channel: Essential Craftsman

Views: 96,783

Keywords: anvil, forge, blacksmith, forging, craftsman, mentor, trades, tradesman, career, smith, carpetner, builder, wisdom, workbench, fabricate, tools, tool, tips, trick, hacks, protip, cutting torch tips, cutting metal, using a cutting torch, oxygen tanks, acetylene tanks, cutting steel

Id: 5y8MjykN3Jk

Length: 13min 47sec (827 seconds)

Published: Sat Sep 26 2020