Oxy Practice

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My first try posting images.  I'm a hobbyist teaching myself gas welding for an airplane project.  I had a few days of instruction at a EAA workshop.  Here's a butt joint of two small pieces of 1/16" material.  I've had trouble getting the combination of 100% penetration, a decent bead profile, and no sag on the backside and this is one of my better efforts today.  I also have trouble starting and finishing the bead cleanly, without burning a hole at the edge.  I'd appreciate any suggestions.  I'll post a sample tubing joint with my next thread.  Thanks in advance. Attached Images
Reply:Here's one of my better efforts at a tubing joint.  Again, any feedback would be appreciated.  I have one more photo showing the backside (inside the tube) I'll put in a separate thread. Attached Images
Reply:I've seen a lot worse.  You are doing very well if a bit inconsistent.A few things to think about. round tube, especially small tube is one of the most difficult things to weld well. You have to constantly be adjusting your torch angle as you go around the tube.  Also tube usually forces you to weld in several positions, vertical, overhead, horizontal... on on the same joint unless you roll the joint and the isn't practical as you start putting bigger pieces together. I'd suggest you start learning the basics on flat material, even if tube is your ultimate goal. The reason is with flat, the torch angle stays the same. This way you can work on the basics of travel speed, adding filler and heat control without the complications of tube. Once you can do consistent beads on flat plate in all positions, move on to tube..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:You can post all these in one thread if you want, no need to make separate threads for each picture post. If you want I can combine the two threads, or we can leave them separate. Doesn't matter.Dips are a bit inconsistent. Practice will help take care of that. Some find it helpful to practice listening to music with a steady beat or even a metronome if you have one to help with dip timing. Bead is a bit cold, but not all that bad. A tight but joint is a bit tougher to get full penetration compared to say a gap, but gaps make it easier to burn thru. A small gap may help, if not more heat.Remember filler chills the puddle and removes heat. You want to balance how hot the torch is, ( settings and distance) with how much filler you add. Nice thing with OA or Tig is that you control how much heat you add and how much filler.Hopefully Makoman will see your threads and comment on them. I haven't done OA really in years except to braze or solder, though I help teach a lot of tig that is very similar in ways. Torch settings and control with OA I'll leave to Makoman to help you out.I left you some comments in your other thread about tube and starting out on plate. Seeing these, I'd definitely suggest working more on plate before you move to tube..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:One thing you need to do is provide a small gap between the edges of the 2 plates where they meet.  You want just enough gap (1/32" to 1/16" is usually good for the thickness you have) to allow the heat to begin key holing the space where the inner flame cone heats the puddle. The trick is to learn how to read the puddle and dip the filler rod to add enough to make the key hole disappear for just a moment.  Learning how to withdraw the filler rod just outside of the flame is also critical to OA welding.Keeping the filler rod just outside the flame allows for the end of the filler to be only a few degrees below melting. That way when you dip it it is ready to melt and fill the key hole.  Withdrawing it too far makes it colder and it takes longer to melt off when dipped, which causes your filling to be delayed.  Keeping the filler rod warmed allows you to make quicker, smaller, and more numerous dips.  Once you get the rhythm going, you can make very decent looking welds.
Reply:Originally Posted by Steverino  Again, any feedback would be appreciated.  I have one more photo showing the backside (inside the tube) I'll put in a separate thread.
Reply:Thanks, I'll ask DSW to merge the threads.
Reply:If you don't mind, please merge my two threads.  Thanks for that and for the feedback...much appreciated. -Steve
Reply:No problem. All taken care of..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Hi Steve, Ok Im going to give you a couple pointers....some you don't want to hear . First things first, forget the tubing, you are not ready yet. Lets start with a butt weld like you have been doing on your flat work. If welding right to left, tack the right corner tight, then gap the left side about 1/8" and tack in the middle, not the left end. Set the torch up so you are welding within about 10 seconds of applying heat. If its slower than that boost the heat, faster than that turn it down.  Keep the inner cone 1/8" from the puddle, never EVER back the torch off to control heat. Heat control is in flame setting and angle ( use 45 for both rod and filler at this point ). If you look through the flame at the puddle, it goes from dull to shiny as the surface melts, if you pay attention to the reflection you will see that if you stay on the puddle long enough the reflection starts to shake like jelly. That is the indication that your are at 100% penetration as you weld, the puddle should always be "jiggly" for lack of a better term, very fluid. Filler is added to the leading edge of the puddle, touch the filler, wait a second for the puddle to melt some off, then withdraw the filler slightly. No need to stab the puddle to death. Now lets see some more practice -AaronBTW where did you take the EAA course?
Reply:Thanks very much Aaron.  I sincerely appreciate the criticism and suggestions.  I understand all of your points and I think I'm seeing all the variables you mention, but don't have them all under good control.  Besides that sense of control, what am I looking for in the result, by comparison to my butt joints above for example?  Just more uniformity?  Or are there obvious flaws in that bead?  Also, any tips on how to handle the edges at start and finish?  Again, thanks very much.  I just scrounged some more 1/16" sheet from a friendly weld shop for daily practice.  -SteveI took the EAA workshop in Chesapeake, Virginia about a year ago.  I'll be heading to Sun 'N Fun in a couple of weeks and maybe do one of their short workshops there as well.
Reply:Originally Posted by makoman1860 Heat control is in flame setting and angle ( use 45 for both rod and filler at this point ). If you look through the flame at the puddle, it goes from dull to shiny as the surface melts, if you pay attention to the reflection you will see that if you stay on the puddle long enough the reflection starts to shake like jelly. That is the indication that your are at 100% penetration as you weld, the puddle should always be "jiggly" for lack of a better term, very fluid.
Reply:Originally Posted by SteverinoThanks very much Aaron.  I sincerely appreciate the criticism and suggestions.  I understand all of your points and I think I'm seeing all the variables you mention, but don't have them all under good control.  Besides that sense of control, what am I looking for in the result, by comparison to my butt joints above for example?  Just more uniformity?  Or are there obvious flaws in that bead?  Also, any tips on how to handle the edges at start and finish?  Again, thanks very much.  I just scrounged some more 1/16" sheet from a friendly weld shop for daily practice.  -SteveI took the EAA workshop in Chesapeake, Virginia about a year ago.  I'll be heading to Sun 'N Fun in a couple of weeks and maybe do one of their short workshops there as well.
Reply:I will make one other comment, which is that if you are finishing your weld at the edge it will tend to get away from you, easy to burn through, due to heat build up in the part, and the fact that there is less of a heat sink at the end than the middle.  With TIG, I can reduce the power at the end to compensate, not so easy with OA.   Consider starting your weld at the edge of the part and working in.  Like other posters, I used to OA weld, but nowadays I TIG anything that I would have welded OA in the past.RichardSculptures in copper and other metalshttp://www.fergusonsculpture.comSyncrowave 200 Millermatic 211Readywelder spoolgunHypertherm 600 plasma cutterThermal Arc GMS300 Victor OA torchHomemade Blacksmith propane forge
Reply:Originally Posted by rafergusonI will make one other comment, which is that if you are finishing your weld at the edge it will tend to get away from you, easy to burn through, due to heat build up in the part, and the fact that there is less of a heat sink at the end than the middle.  With TIG, I can reduce the power at the end to compensate, not so easy with OA.   Consider starting your weld at the edge of the part and working in.  Like other posters, I used to OA weld, but nowadays I TIG anything that I would have welded OA in the past.Richard
Reply:Hey, thanks for all of this feedback and sorry for the delayed reply.  I got busy with other things and didn't log on for a while.  Much appreciated.  I'll keep at the practice and post some more pics as soon as possible.