Cutting Torch - Tips for Oxygen Acetylene Cutting

hey thanks for watching another video from welding tips and tricks calm today we're talking about doing some oxy-fuel cutting and a little disclaimer for you this is not a comprehensive oxy-fuel safety course you can get a very good DVD from Smith torch equipment and today's video is mainly on just some tips so what does a pocket reference manual for welding drill index and an autodarkening welding helmet have to do with making a good cut use an oxy-acetylene oxy-fuel welding equipment because there's a lot of difference in using the right stuff and the right pressures and the right settings and right techniques for getting a good cut today we're talking about acetylene only there's lots of other fuel gases like propane map gas propylene and all that today we're talking strictly on a settling because seems like more you know hobbyists and more small type fab shops use acetylene than other fuel gases so before you light up after making sure that everything is in good order your your cylinders are chained securely and everything there's a sequence of setting up and shutting down light the torch once I've made sure that there's no pressure on these gauges at all on either side and that the adjustment screws are loose there's no tensioning on the springs ready to turn the gas on but human nature seems to be I want to see how much gas is in there I want to see those needles move so I've watched a lot of guys and typically they turn it on just like this walking and a little too fast you want to turn this on very very slow there is a phenomenon called the heat of recompression if there's already pressure in here left over and you shoot a bunch of pressure in there the temperature spikes momentarily all it takes is a speck of dust a little bit of oil anything in there becomes fuel and you get our regulator burn out our Bo if you don't believe what I'm telling you just Google our Bo our Bo OSHA incident our Bo accident regulator burnout you'll find all kinds of things all kinds of reports where people have been injured by turning this on too fast while there is still pressure in here because regulator burnout oxygen saturates the clothes and is a big problem bad bad burns on the torso and works so what you want to do is there's no point you don't need to see the needles move does no good you can see them after the fact all right so really the same thing to do is get at arm's length and look away look away is that thing for some reason it explodes on the log rather head it haven't hit me here then in my face right okay and it's not going to explode because what turn it on nice and slow after making sure there's no pressure in here so let's go alright I'm at arm's length I'm cracking it as slow as I can so don't shoot a bunch of pressure in there and then once I get it done I can crank it open as fast as I want and backseat that valve because it's a backseat valve it's a high-pressure cylinder oxygen nitrogen and others are high pressure cylinders and have a backseat type valve the acetylene now I don't have that same risk but I still don't want to turn it on fast just because alright so I want to crank it slow but I only want to turn it maybe half a turn sometimes half a turn won't even make the regulator register and in which case you're going to have to turn it maybe three-quarters but the point is don't turn it open all the way because if something bad happens you want to be able to shut it down quick like that one turn of the wrist or or to get the most sometimes these stems leak and sparks will get over here and ignite the stem on the ignite the gas leaking around the stem but maybe the valves packing it isn't just right and you get a flame here and you kind of want to be able to turn that off quick without crank crank crank crank crank in fact there is a point at which you don't even want to turn it off if that flame is shooting up this high you know it's time to get out of Dodge it's not time to grab a glove and try to crank that thing shut that's it that's a judgment call the CGA the compressed gas Association basically says that when it is safe to do so there is some kind of flame here and turn it off so you know if it's a little match toss match sized flame personally I'm not saying this is the thing to do just telling you what I would they do I probably reach over here as quickly as I couldn't turn it off again shooting up here and I see them I see the valve starting to melt I'm out of there all right so I've turned this open roughly half a turn now where do I set these gauges okay I set them at 10 and 40 not really because it depends on what tip I'm using it depends on pixel thickness of the metal it depends on the manufacturers guidelines the manufacturers for oxy fuel equipment are all different torch heads are all different they mix differently there's different designs Smith for instance as in in the head mix and Victor is in the body typically okay and others so it requires that they've done their homework and they have tip charts recommending the the safest and optimist optimum pressures to get a good cut and also to be safe okay so one way if you do not have any manufacturers tip charts maybe one way is to just determine that center hole size by using a drill index and then consulting some type of a chart at center hole is really the main thing when determining how much oxygen pressure you need so somebody emailed me about this little cool little book published by Adele it's called the welding pocket reference you can get it on Amazon and I ordered it just to see if it was any good and see if I could recommend it well I can't recommend it it's a good book and it does have a few little technical errors in it but it's a good book another one is the welding encyclopedia and I've got a 1964 Edition that I got from Amazon these are hard to get you're going to drive yourself crazy trying to get a good one you know being a 1964 you would think it wouldn't be useful it's very useful there's an old saying if you need a new idea read an old book and I think that's very true and probably the reason is that these days we're so smart that we we forgot a lot of the basics so it reminds you on a lot of the things that you shouldn't you should already know so once you know the settings once you determine the pressure settings beaten by the manufacturers guidelines tip chart or by other either using a drill index and looking it up in some other reference manual set the regulator's then after you do that open each torch valve momentarily to purge for a little while to make sure you don't have any mixed gases make sure you've only got a set Alain and only got oxygen in each line and then when you light only use acetylene but use a full half turn that way you won't get the little wimpy little flame with a little black paratroopers that get all over your face you'll get a good safe flame with a lot of flow that won't pop back and you won't have mixed gas situation going on inside the torch head or torch body with a potential for a flashback and then then to set the torch if it jumps away from the tip which a lot of times it does you got to back it back down and then increase it to wear the suit just starts to go away there's barely any sitting the flame that's your reference point that's your reference point to get the most out of a tip and have adequate flow to keep that tip cooled off keep it from getting hot keep keep flashbacks from happening then add oxygen to the flame and continue adding oxygen to get a neutral flame which means basically your cones define without any feathers on the end of them and then when you give it a little giving a little extra pressure by hitting the lever you might have to add a little action to keep those flames from changing much on you and now you're ready to cut now you should have proper eyewear and I like to use actually autodarkening welding I got a couple of them that have a cut and grind mode this is a Miller digital elite got four sensors on it it's a really good helmet and I can keep my cheater lens in there my magnifier and I can sit in either the shade 3 for a grind mode or seed 5 for a cut mode it doesn't know whether I'm cutting or or grinding and so depends on how thick of cutting I'm doing if I'm cutting really thick stuff I might set it on five but shade three sometimes it's good for cutting so I'm using this tip and it's kind of like again it's like a forty thousand cut orifice and I said it accordingly I'm cutting quarter inch metal here now that's not a bad cut but it's not a great slags kind of hanging on a little bit rounded the top corner it's uh it just didn't do a really really clean job for most things that I do you know a lot of times that that slag would probably knock off pretty good but keeping the same tip in the same settings I put some three quarter inch metal up on the table here I'm going to cut it and it cuts it just fine I didn't have to go ultra slow but you'll see the difference in the quality of the cut here in just a sec same tip so that's a cleaner cut basically no slag hanging on the bottom pretty straight the top is not rounded off much pretty good clean cut so this tip is probably best for around half-inch did fine for 3/4 inch thick metal so use the right size tip for the right size job and you get a lot better cut and a way to do that is you have to have some kind of reference manual like that little audio book now I'm going to show you kind of how I cut here I usually cradle one hand in the other hand make a few dry runs and you know that I can make circle cuts like this I can make a good 12 14 inch long cut without any problem and this is the 3/4 here I'm using a buck 10 on the acetylene at about 45 to 50 on the oxygen for this three quarter inch stuff and what you want to do is try to go to smooth and steady don't go ultra slow you'll know if you go too fast it'll blow back on you and won't cut all the way through so you kind of find where that edge is and you go just fast enough and just slow enough to make the cut and fast enough not to leave a bunch of slag and melt that top corner off a lot all right now when you're done cutting for the day there is a certain way you need to shut down so to shut down I want to shut the fuel gas down now manufacturers very on this but most will tell you shoot the fuel get to turn the fuel gas off and then it turns the flame off then you turn the oxygen off here what's next this is a critical step next because if you can remember this everything else will make sense going forward in the shutdown procedure first thing I do is I shut my eyes shut my flame off turning the gas off the fuel gas off first then the oxygen next thing is the regulator alone the next thing is go to the power source go to the main source as if it was a lockout tagout procedures on electrical things this is the shutoff switch so I'm going to turn off the source okay pauley off this is how you shut down properly leave it set safe for the next guy all right I've turned goes all the way off I'll do this next no no I don't because if I do that I can't bleed it off here we'll leave pressure in here that's that's the dangerous situation for the next guy with that recompression thing that I mentioned earlier so the next thing is a bleed bleed off here I can do that most quickly on the oxygen just by hitting the leaver it goes all the way down to zero on there gages done there then I'm going to bleed off the acetylene let it go bottom out all the way down nothing there then I'm going to shut off all the valves here and then what I want to do is back these screws off to where they're loose those no tension no spring tension on them that leaves it safe for the next guy in case he doesn't remember you didn't leave any pressure in here you didn't leave any pressure in here so now you know if he does he's not spooled up on these safety procedures and he turns us on suddenly it's going to be safer for him is a lot less likely for him to to get that regulator burn out our Bo okay so you know the best the best advice I can give you is get the manufacturers guide and follow it as far as pressures as far as sequence of setup and shut down and all that this is not a comprehensive safety course the best one I have seen is Smith torch company they make about a 40 or 45 minute DVD very comprehensive very thorough that in conjunction with a hands-on setup shut down procedure and a written test makes for a good oxy-fuel program the main things don't turn this on sudden make sure before you even turn it on that you don't have any pressure on the gauges and that this is loose so you know there's no pressure in here in between the regulator body and the main cylinder valve okay now another main thing is look away and crack it slowly when you turn it on crack it very slow okay not fast slowly crack it slowly then you can crank it and open it up all the way and then the other thing is don't add oxygen to the flame when you're lighting that just creates an extra risk you know it's a risk of flashback always have check valves you know at the bare minimum you you definitely need check valves if you want to get flashback of restrooms and have check valves built-in that's probably a good idea don't add oxygen to the flame when you light it just add more acetylene so that you don't get too sick won't hurt to get a good heavy acetylene flame you know when you light it doesn't hurt a bit then you can back it down and then the main thing that makes the shutdown sequence makes sense is going back to the cylinder right after you shut off the flame turning off the cylinders then bleeding it down then packing these off and you're done all right be safe thanks again for watching another video welding tips and tricks calm

Channel: weldingtipsandtricks

Views: 752,076

Rating: 4.8929744 out of 5

Keywords: cutting torch, how to use a cutting torch, oxygen acetylene, oxy-fuel, welding safety

Id: AOYQEg9SXoA

Length: 15min 24sec (924 seconds)

Published: Fri Sep 23 2011