Noob with questions

[Rowdius]

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.

[lugweld]

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.

[specter]

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).

[Oldtimer]

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.

[Magnetic Mechanic]

When they welded those ships they used some really big torches.
I got these from my wife's grandfather. there from Bethlem steel.

[Rowdius]

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 side

[Rowdius]

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#1



backside:



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.

[Oldtimer]

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.

[El_Lloydeo]

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)

[El_Lloydeo]

And listen to oldtimer. Good advice right there.

[Brianstick]

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.

[quasi]

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.

<waits for somebody to tell me how wonderful oxy-fuel welding is>

[Rowdius]

Originally Posted by El_Lloydeo

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)

Well, it is actually a requirement of the class, but he wants to focus more on the SMAW than the OAW, and he has given information out that is completely opposite of what is in the text book and found here. I really like the guy, I just feel a little cheated on the OAW.

As for the welds, most of the broken pieces have filler material on both sides. Mostly the welds seem to be breaking down the center. I'm thinking I may not be going deep enough with the puddle. The good news is that the practice is fun. I'm going to either try Oldtimer's idea of going up a size on the tip or maybe going down to 1/8 on the steel (assuming I have some on the scrap pile)

Originally Posted by quasi

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.

Well, I'm moving on to smaw in the class, but I really like the OAW, and want to get decent at it. I'm not really taking the class to get a job, just wanted to learn. Besides that, right now to use my stick welder I have to drive the tractor into the shop, pick of the welding machine and carry it to the power. It is a pain, where I can have puddles of motlen metal with the torch in seconds.

Originally Posted by brianstick

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.

This could be it. He is the Ag teacher for a small highschool during the day and teaches a couple of classes at the junior college nights/weekend. His class was also one of the last to fill up.

Thanks for all the help everyone. I'm going to keep playing/practicing. I'll probably posts some of my SMAW questions, frustrations and discoveries as they occur.

Oh, here is a photo or two of a set of forks my brother and I built for my tractor this summer. He welds for a living, and was there to make sure I didn't come up with something that would kill people. If you see pretty welds, they are his. The hideous torch work is mine before I took a grinder to it

[Rowdius]

Originally Posted by Oldtimer

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.

Thanks. The victor book that came with the torch said #3, but I think I'll grab a #4 if I go to town tomorrow, or drop down to a smaller hunk of metal if I can find some on the pile.

[DSW]

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.

[Bgbkwndo]

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.

[Craig in Denver]

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.

[Oldtimer]

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.

[makoman1860]

Originally Posted by quasi

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.

<waits for somebody to tell me how wonderful oxy-fuel welding is>

It all depends what you work on. In aviation repair and fabrication it is still used frequently. Thats because of the materials and situations involved. Production has gone away from it for economic reasons. Up until the 1990's aluminum welding with the torch was common on airliners for ducting and such, until OSHA had a fit with the fluxes and forced the change. On certain materials it has an advantage as it eliminates the need for some post weld operations.

I have a feeling that the reason the general welding community doesnt like it, is that it seems too simple to them. Maybe they try to justify the money they just spent on a shiny new inverter Tig machine with all sorts of lights and buttons and digital read-outs, by saying that there is no way that this simple fuel burning blowpipe can do the same job, on the same material, and in some cases better. I think its just human nature, why do we need carbon fiber fishing poles when we used to catch the same fish with bamboo?

And I OWN 2 inverter tig welders....they are great, but for many of the materials I work on, they offer NO engineering, user, or metalurgical advantage, so when people working with those same materials, ask me what I would suggest to them, I have a hard time telling them to invest the money in an electric machine. Unless they have no skills other then to impress their friends with shiny machines in their shop.

[El_Lloydeo]

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.

[Rowdius]

Originally Posted by El_Lloydeo

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.

Sorry, 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.

[makoman1860]

Originally Posted by Rowdius

Sorry, 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.

How are you cooling the welds when your done? What filler did you end up using? What flame setting?

[Rowdius]

Originally Posted by makoman1860

How are you cooling the welds when your done? What filler did you end up using? What flame setting?

I 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.

[El_Lloydeo]

Did you go with a plastis or wooden coat hanger? haha

[makoman1860]

Originally Posted by Rowdius

I 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.

Well,
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.