Noob with questions

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I've been lurking through here for a little while, but here I am out of hiding.I've started a SMAW class, but we had a small intro to OAW (more to make sure everyone could use a cutting torch.)  The OAW was basically a few hours with the lecture being "I guess OAW is okay for putting something back together long enough to get it out of the field to fix it, but that is about it." Either way, we've since moved on to SMAW.The problem is that I really liked the OAW.  Liked it enough to buy a torch.Anyway, back in class we did the classic corner weld without filler metal, and one or two butt welds with filler.  All done on 3x3x3/16 plate.  When I set up my first butt weld, I left about an 1/8" gap between them, as that is what I had been taught for what little stick/mig I had learned on my own before starting this class.  He watched me, didn't say anything.  It was not a pretty weld (as I said, my first oaw weld.)  When I showed him, and pointed out the gap I didn't fill, he said, " you put that gap there before you even started."  I went on to ask if that was not the way to do it, and he mentioned that we would be doing it in the SMAW part of the class, but for OAW to just butt them together.My next couple of welds actually looked pretty decent, but did not penetrate all the way through.  When I questioned him about it, he pretty much said that penetration just isn't possible with the OAW process. After some more reading here and in my text book, I've learned (or at least think I have) that with anything over 1/8" thick needs to be beveled for OAW. Which leads toward my first actual question in this long-winded post...  Is this true?  For anything over 1/8" thick, do I need to grind a bevel for good penetration?  I've been practicing on 3/16" plate at home, and can usually make fairly decent looking welds in the flat postion, but they are not pentrating all the way through, and fail my destructive testing (big ol boy with a 3lbs hammer.)I really like the instructor, and the SMAW part has been good so far, but I'm not sure if he has been leading us wrong about the OAW.  I'm starting to think that maybe he learned it incorrectly, does not enjoy it, had a family member murdered with OAW or something and that is why he just does not like it.
Reply:Welcome Rowdius.Good to have you here.Your teacher is an idiot, get another one.  Yes you should put a gap, the width of the rod you are using.He is a fool...not to teach you the "Art" of O/A welding.  There is no better time or way to learn the basics of welding than with O/A.  If you can O/A, you can easily acquire all the other kinds of welding.Penetration, not possible with O/A welding?  Its a wonder all those ships made at the turn of the century didn't sink along with the Titanic.  Ask him what process they used to join hull plates that were .5 inch thick or greater.  If you look at torch welding heads, you will see that you can get some that will weld in excess of 1 inch.He is not qualified to teach, because 1) He is dispensing wrong information.  2) He is avoiding the requisite practice on O/A that is a must for properly developed skills.On 3/16, you should not have to bevel you welds.  It will penetrate right on through, if you leave a gap.  You will have weld deposited on both sides.  Also, you should be able to bend it both ways without breaking.  I had to "test" out on 1/4 plate and have it bent both ways.  Mine did not break or crack.  It is hard, because only 2 class members attained that.  If you know how to weld with O/A then activities such as brazing are natural as well, and you can make an nice, smooth bead instead of looking like it ran all over the place.Although some people learn to weld without it, I can't even imagine me learning to weld without that as the foundation of my  skills.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:I agree with the lug on this one. Sounds like the instructor really doesn't know much aboutO/A welding. Perhaps he is more experienced in the other types of welding and is required to teach an area he is really not experienced in (benefit of doubt here).Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Lugweld summed it up quite well. This is the problem with welding classes. If you get an instructor that knows what he is doing you will learn. If you don't then you are just wasting your money. Since you are a student you have no idea whether you are receiving correct information or not.
Reply:When they welded those ships they used some really big torches. I got these from my wife's grandfather. there from Bethlem steel. Attached ImagesA butterfly without wings, is just an ugly bug
Reply:Thanks for the help lugweld.  I think since the class is actually an intro to SMAW class he doesn't have the time to do more than just a little on the OAW, though I don't agree with it.Okay, I went out and did a little bit this morning.  First was a bevel, but with coat hanger for filler (could not find the filler rod I bought last night.)  It did not survive the hammer.  Oh, and here a backside:Then I found the filler rod and tried a few more with and without a bevel.  Nothing really held.  Beads looked fairly pretty, but not very deep.  Perhaps I am moving too fast?  I have my regs set 5/5 for my #3 tip. My torch sounds louder than what my instuctor suggests, but I adjusted the acet. until there was no black smoke, then added O2 to get a neutral flame.The last one I did held, but I welded both sides.  Before welding the second side, it looked a little beter, but still not all the way through.  I wish I would have beat on it with a hammer before doing the second weld.Here is the last one that held. It is not as pretty on the front, and has a pin hole.Front side:back sideLast edited by Rowdius; 02-04-2009 at 12:48 PM.Reason: fix img tags
Reply:Okay, did a little more.  Adjusted my gap to my filler rod, which might be part of the problem, as that I'm (trying to) weld 3/16 with 3/32 rod.Made three welds.  None of them held, but they all were stronger than my last attempts.  One of these bent quite a bit before the weld broke.Weld#1backside:Weld#2 (the one that held best before breaking)backside:Weld#3 (which I did not grind the slag or smooth before welding)backside:Some of the breaks:I don't know if I'll have time to set up again today, but I am going to get some bigger rod.  Also I think I'm going to back my pressures down to about 4/4 and see if I can heat through without blowing the puddle everywhere.Even though I'm sucking at this, it is a lot of fun.Last edited by Rowdius; 02-04-2009 at 02:27 PM.Reason: fixed huge photo
Reply:Try going up to a #4 tip and using a little softer flame. You can get more heat without having to crank the pressure up at the tip so much which should give you better puddle control.
Reply:Thats pretty cool that he takes the time to show you a little oxyfuel. He prolly knows more about oxyfuel than you think. Some people (like myself) just find it very dull. I would be surprised if anyone could even get a job doing OAW. If anything I would say if you like it keep doing it cuz it looks like you do it well. It is a form of art though. Did he tell you that you can use a coat hanger to do it? Dont use wooden or plastice ones though. Your butt joints are breaking because they are only welded on one side. Turn it over give it a nice little back gring and put a weld on that and try breaking it. Unless u have adequate penetration in a butt joint it will always be a weak joint when welded from one side. (PJP)
Reply:And listen to oldtimer. Good advice right there.
Reply:I don't know where Rowdius lives, but in our area there are a shortage of teachers for the night classes. I know of one case where one teacher was teaching three different classes. He was teaching Welding 1, Machine shop 1, and Basic AC/DC electricity. I had a chance to talk to him and although he had some knowledge in those areas, he was not qualified to be teaching. He was filling in until a new teacher could be found. Without him, the classes would not even be available.
Reply:i spent 7 months at ~30 hours a week in welding school and didn't learn a lick of oxy-fuel. i won't say that it is pointless but i have never heard of a shop that used it. the only time i have ever heard of it being done is by people that want to be old school for no other reason than being retro. i think you learned the basics of the process and should move on to more relevant welding methods.
Reply:Originally Posted by El_LloydeoThats pretty cool that he takes the time to show you a little oxyfuel. He prolly knows more about oxyfuel than you think. Some people (like myself) just find it very dull. I would be surprised if anyone could even get a job doing OAW. If anything I would say if you like it keep doing it cuz it looks like you do it well. It is a form of art though. Did he tell you that you can use a coat hanger to do it? Dont use wooden or plastice ones though. Your butt joints are breaking because they are only welded on one side. Turn it over give it a nice little back gring and put a weld on that and try breaking it. Unless u have adequate penetration in a butt joint it will always be a weak joint when welded from one side. (PJP)
Reply:Originally Posted by OldtimerTry going up to a #4 tip and using a little softer flame. You can get more heat without having to crank the pressure up at the tip so much which should give you better puddle control.
Reply:I'll agree that OA welding will help you out on other methods. I learned only OA 25 years ago and when I went back to welding and started to learn mig, stick and especially tig,, that exp. really helped.I agree that your instructor most likely didn't have the time to show you more than basics. In my SMAW class all we got was OA cutting on the 1st nite, so they knew we would be safe with the torch. The instructor did offer to teach anyone interested in OA welding or brazing after the 5th class if anyone was interested. Not many took that option.The test pieces look dirty to me. I see a lot of what looks like mill scale and rust on the tops of the pieces. You will NOT get good welds if you contaminate the weld by pulling crap in from the surface. I would grind all the pieces. Grind not wire brush, the brush won't remove the rust and scale, just polish it. Good prep is important in all welds. Some rods like 6010 can go thru a lot of crap, but you will still be better off if you remove as much junk as posible.Looks like you are doing good. Glad to see you learning OA, I don't think you will regret it.
Reply:I've been retired from the welding trade for a couple of years now, but have fond memories of welding with an oxy-acetylene torch. Did a LOT of small bore pipe [before the T.I.G. process was as prevalent as it is to-day] and to x-ray specs. I always used the "backhand" method of putting in the root bead. With this method, the torch precedes the filler rod. The base metal is heated to melting temp., and then the torch flame is directed into the gap, until a "key-hole" is opened up. Filler metal is introduced into the puddle, and virtually pushed to the back side of the joint. As you progress, it is mandatory to keep the keyhole open to attain full penetration. Subsequent passes are made in the forhand, or usual travel method. Hope this helps your on your road to success.As a welding instructor for many years, I also observed that the fellows that knew how to weld with the oxy-acetylene method, made the transition to T.I.G. welding with very little difficulty.  Just my $.02 worth.Bgbkwndo.
Reply:All manual welding depends on puddle control and O/A slows it down enough for a new guy to see it, learn it and control it. I've attached a pic of a 'keyhole'. Its not being there is why your welds are breaking. You can see it from the top, while welding; it isn't something you have to quit welding and turn over the piece. When you look at the backside of your weld, you should NOT see any remaining straight edge of the original pieces. In other words, if you can see a straight line, that's where it will fail. Most butt welds need a gap and/or a bevel.I took an O/A class last year, bent 12 (3 each; flat, vert, horiz, ovhd), no failures. 3/16" material, beveled sharp, 1/8" gap, 1/8" filler, RG-45. I found the flame louder than I expected, but everyone's was. Don't weld directly on the table, we used firebricks; just as long as your weld is off the surface. I used 8lbs on both gases. I agree with Oldtimer on a #4 tip.O/A is all I had for 16 years. Your puddle looks good. You are adjusting the flame correctly (no soot, add oxy to neutral). Remember that each tip size has several hundred degrees adjustment from where you started (no soot, neutral). So if you need a little more or less heat, it's right there at the torch valves.Pic 1: The Hobart Manual I learned out of.Pic 2: The bevel and set-up.Pic 3: The mandatory keyhole.Edit:Weld#2 (the one that held best before breaking)That's correct, we used two passes; the second to fill. Both forehand. I've never been comfortable with backhand. Attached ImagesLast edited by Craig in Denver; 02-05-2009 at 01:05 AM.9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:Good words and pictures, Craig.No, O/A isn't used much anymore. It is slow compared to any arc process. And time is money as everyone points out. There are still certain applications where it works better than any other process though and places where it is an alternative for a one time or very occasional job that doesn't justify the expence of equipment that will be used very little. If I were designing a welding school course the first phase would be in A/O to teach the basics of joint design, fusion, penetration, and puddle control. Then the students would move on to the various electric arc processes.
Reply:Originally Posted by quasii spent 7 months at ~30 hours a week in welding school and didn't learn a lick of oxy-fuel. i won't say that it is pointless but i have never heard of a shop that used it. the only time i have ever heard of it being done is by people that want to be old school for no other reason than being retro. i think you learned the basics of the process and should move on to more relevant welding methods.
Reply:There might be filler metal on the back side but it sure didnt fuse. If you want to weld that joint from one side and make it hold you better get that keyhole going on.
Reply:Originally Posted by El_LloydeoThere might be filler metal on the back side but it sure didnt fuse. If you want to weld that joint from one side and make it hold you better get that keyhole going on.
Reply:Originally Posted by RowdiusSorry, I put that poorly, I did not mean both sides as in top and bottom. I mean left and right side.  The welds mostly break right down the center, leaving filler on each side of the break.  But, I agree it is not fusing.I did a couple this afternoon, got the keyhole (well, mostly.) and it was the strongest weld yet.  I broke a pair of visegrips (yeah, I need to get a vise) when I was beating on it with a 5lb hammer.  The weld bent.  Only got it to break as I was beating on it the other after bending it over 45 degress the first way.  So, at least there was progress today.Also, I put a piece of this plate I've been welding under the chow saw and this stuff is pretty hard.  The saw bogs down pretty good cutting it, more so than when cutting sucker rod.  I wonder if this has anything to do with my trouble.I'll try to get a couple of photos tomorrow when I try again.
Reply:Originally Posted by makoman1860How are you cooling the welds when your done? What filler did you end up using? What flame setting?
Reply:Did you go with a plastis or wooden coat hanger? haha
Reply:Originally Posted by RowdiusI usually quench in a bucket of water after each weld, unless I have several coupons laid out to weld, then it is after I finish them all.I am using RG-45 1/8 filler.  At first I used RG-45 3/32, and then a couple with a coat hanger.I am using a #3 welding tip with about 5/5 set on the gauges.  My text book suggests 4/4 with a #4 tip, but the book that came with my victor torch suggests #3 for 1/8-3/16 with O2 set 4-7 and acet 3-6.  Or a #4 for 3/16-1/4 with O2 5-10 and acet 4-7.  I mainly have been using the 5/5 as that my gauges are hard to set anything smaller on the Oxy side of it.I bought a #4 today, and will try it tomorrow, though I might play with my pressures on the #3 first.Originally Posted by El_LloydeoDid you go with a plastis or wooden coat hanger? haha
Reply:Originally Posted by makoman1860Well, First off dont quench it, just let it air cool slowly.Second, be sure your using a neutral to 1/2x reducing flame.Third, dont be too concerned with pressure, and tip size should be an issue as long as its large enough. When in doubt, go larger and move faster. Work on that penetration and dont be affraid to build up a higher bead.
Reply:Originally Posted by RowdiusI guess I typed out a whole lot trying to answer your flame setting question without actually answering!   I have been using a neutral flame.The pressures worry me only because I've read (and heard from my instructor) that I should have a quiet flame, and mine is pretty loud.  However, I am turning the Acetylene on the torch up until there is no black smoke, and then adjusting to a neutral flame with the O2.  My instructor never mentioned turning up the acet until the black smoke is gone, only to make sure the flame was still attached to the torch, and have a couple of inches before the "skinny" part of the flame becomes feathery and large.  Going up until there is no black smoke makes for more of a roar than "wind over a birds wing" that i've read about here.
Reply:Makoman,I appreciate your post and as well those of you that stated the importance of OA welding.  I am a AP mechanic and welded a lot of AC tubing and as some of the rest of you did not have anything except a torch a few tips that we cared for like a mechanic does his Snap On wrenches!  I am now retired and only weld to justify the tools in my shop and fix/fab and experiment with ideas that amuse me.Just recently I purchased a Tig inverter and along with my past Construction and AC welding experience I am teaching myself (along with all your help) to tig weld.  I am progressing well with ferrous metals, I think due impart to my hours and hours of OA welding, most out of position stuffed in a fuselage that was bent in the Alaska backwoods!  (even these little tig machines would be no use out there with the wind blowing 50!  Roudius,I admire your enthusiasm and attitude, You are on the right track and don't quit asking questions to the instructor (you are paying the bill)  You are not far from turning out great welds (as someone said) the importance of cleaning the material in the weld area should never be overlooked to get a good consistant weld---In OA you don't have the advantage of a shielding gas so the contamination is just drawn right into the puddle and then we just push it around!Tim----humbled greatly by the young and old that can perform AL tig like De Vinci!!A rich man is not the one who has the most but instead one who needs theleast. Retired IUEC local 19AK Bush pilot,  Chaplain  CMA Chapt 26victor torchesMiller110v migDynasty 200dx (new in Dec 08)Hypertherm PM-45MM-252 (new 2/09)
Reply:Makoman1860:I just learned 'stepping'. It's one of the best O/A tricks I know. Turn the heat UP with the fuel, because it's hotter. Turn it DOWN with the oxy, because it's cooler. As you said, doing it in this order will show the feather; which is what a guy needs to see to adjust to neutral."Its hard to tell by sound nowdays with modern torches."Rowdius:A bigger tip will be quieter at a given BTU. And don't sass your instructor, you won't change his mind. It's a fact of life, YOU have to add together all the inputs (from your instructor and from here) and make your own conclusions.9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:Originally Posted by makoman1860Well, That flame setting could be called an initial setting. From there, if you want cooler, close the oxygen until you get a 1" feather, not close the fuel to regain neutral. This is what we call a "step" in flame size. To go up, add fuel to get a 1" feather, then oxygen to regain neutral. This is going UP a step. If the flame is getting too short, drop a tip size, if your pushing the flame way out, go larger. Its hard to tell by sound nowdays with modern torches. Half of the time the tips are made so poorly they are noisy no matter what! Basicly respond to what the torch is doing for you, if its taking forever to form a puddle, boost the heat and/or go up a tip size. If its going faster then YOU can, step down the heat or tip size. If you use too little gas flow with a given tip, you may get a POP. In that case go DOWN a tip size and raise the gas velocity. If the torch sneezes, go UP a tip size. I know it sounds odd. Once you know it, just by eyeball you will be able to grab the right tip and set the right flame size quickly.
Reply:Originally Posted by Craig in DenverMakoman1860:I just learned 'stepping'. It's one of the best O/A tricks I know. Turn the heat UP with the fuel, because it's hotter. Turn it DOWN with the oxy, because it's cooler. As you said, doing it in this order will show the feather; which is what a guy needs to see to adjust to neutral."Its hard to tell by sound nowdays with modern torches."Rowdius:A bigger tip will be quieter at a given BTU. And don't sass your instructor, you won't change his mind. It's a fact of life, YOU have to add together all the inputs (from your instructor and from here) and make your own conclusions.
Reply:Aaron,right on!  It easy easy to see you have burned up a shirt or two on tubing clusters (LOL)  I remember one time welding in a broken gear fitting on a cub laying in the snow with a tarp over the fuselage when I heard my buddy yelling (what the #^Tl) are you doing?  I pulled off my little goggles to find myself on fire!  Evidently I had got my insulated coveralls agains the cluster while I was heating the backside of a tube.  Don't know why I shared this???  Got to love my little  smith torch with forward controls that you can reach with your index finger! (ever tried their Cyclone)??TimA rich man is not the one who has the most but instead one who needs theleast. Retired IUEC local 19AK Bush pilot,  Chaplain  CMA Chapt 26victor torchesMiller110v migDynasty 200dx (new in Dec 08)Hypertherm PM-45MM-252 (new 2/09)
Reply:Originally Posted by RowdiusOh no, as I've said, his SMAW teaching seems to be more in line with our text book and the info I've found here.  Since the OAW part of the class is over, I've just accepted the fact that he does not like it for some reason and/or does not know as much about it as he does SMAW.  I just want to get good at OAW, not become a headache for my instructor.Again, thanks for all the great help everyone.
Reply:the books recommend pressures  but the gauges arent accurate enough to set the fine difference between 4 and 5 pounds..the main thing is that when the force of the flame is too great the puddle flows/blows around..when o/a is working good for me the puddle sits there like a fat ball of butterscotch...