It was fun, now a few questions

I'm trying to learn gas welding. I bought a Harris torch and today tried it for the first time. I was welding 1/8 steel. Used the tip suggested by the mfg. Set pressure to 5psi as suggested and welded some flat beads and some T's.

First question. Is there a way to determine how much to appropriately open the acetylene. I remember reading somewhere that it should be high enough that the actual flame under just acetylene should be about 1/8 inch away from the tip. Is this correct?

Second question. I don't really know I can adjust for a neutral flame. I am partially colorblind so this may not be a good way for me. I saw somewhere adjust until the inner cone becomes well defined. Also saw references to the hissing sound. Should the inner cone be small and well defined such as 1/4 inch or would it be longer when neutral. It seemed that the inner cone would get so small and then not change much. Really could not tell much color. The sound seemed inconsistent at times but I did note a hissing sound with just acetylene that continued with the oxygen as I turned it up. Then at a point the hissing would abrupty drop off and become much quieter. Is this a sign of a neutral flame. It seemed that the hissing was also a function of how much the acetylene was open but there was a clear point at which it dropped off.

Third Question. I tried some T joints and of course had the well noted problem of undercutting the vertical piece. Of course, I did not notice it during the process. I clearly had too much heat on the vertical part. I think the reason I did this is I did not really like the way the puddle was forming. Perhaps you can tell me if this is normal. The bead tended to develop in a U shaped configuration with the arms being on the horizontal and vertical components pointing in the direction of travel. The concavity of the bead was right at the vee and I was concerned I was not getting the corner hot enough and as such likely overheated the vertical component. Is this a normal shape for the bead or am I doing something wrong. Is my weld likely weak at the actual vee because of how thw puddle formed. I guess there is a chance the filler/weld simply bridged the corner. When I get a chance, I will cross section the piece.

Fourth question. Is .125 thich material good to practice on or should I try thinner.

I thought I did some nice looking beads on just flat stock. They were straight and had that fish scale look. There was some irregularity of the underside which I think suggests I got good penetration. It was a lot of fun.

Any input would be appreciated.

Thanks

Barry

Reply to
BP
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A good guideline for torch settings is to open you acetylene, light up and increase your gas until the smoke disappears. Open a bit more and you will see the yellow flame jump away from the torch tip leaving a gap. You now add oxygen to get your neutral flame. To get a neutral flame increase oxy until the feather all of a sudden changes to a hard distinct cone. Decrease your oxy watching the feather reappear. remove the feather again. If you turn your oxy too much you have a very tight hard pale blue cone that is an oxidizing flame. The excess oxy will burn the iron in your weld pool giving you oxides that contaminate your weld and leave a poor finish on your weld bead. If you have excessive noise from your tip it is time to reduce your settings a bit or if you really need the heat, change to a larger tip. The torch tip is bent at an angle . If you were to hold the torch handle horizontally the angle at which the tip relates to the work surface is the ideal angle. Holding your torch handle way off to the right pointing left and your left hand holding the rod out to the left side in front of the flame is awkward. Just remember that angle and duplicate it as you are welding in a more comfortable position.. If you need more heat you aim your torch by twisting your wrist. the torch points more downward or twisting the other way the torch points forward throwing the heat in front of the weld pool. You seem to be successful at flat beads. Fillets are a trick. My suggestion is to aim the torch straight into the corner at ninety degrees to start. You twist your wrist to point it forward. Aim your torch at the corner then to a point that is approximately 1/16 onto the flat part of your TEE joint.. If you point the torch toward the corner exactly the heat rebounds up the vertical wall and overheats that surface. The result is that you get undercut along the upper edge of your weld bead. .125 is an ideal thickness for a beginner. It sounds like you are well on the road to success. Randy

"BP" wrote in message news: snipped-for-privacy@corp.supernews.com...

Reply to
Randy Zimmerman

I am teaching myself as well, and did my first welds day before yesterday, building a small work table for practice. I'm sure you are having a lot of fun with it cause I certainly am.

That's what I arrived at just through experimenting.

You will see an inner cone and an "inner-inner" cone at a certain point. The difference in brightness should be enough even if you can't make out the rather small difference in hue. I think the inner cone I am seeing is the "feather" that Randy mentions?

I am using 1-1/4" x 1/8" angle iron and it seems a good balance between being too thick to heat up quickly and get good penetration and so thin that I am afraid to melt or blow holes in it.

There is a tremendous difference, for me, between 5 psi and 7 psi, and I had a lot of fun experimenting with different gas pressures. Today I will try a couple of different tips.

I got some disgusting looking cold welds the first couple of attempts that of course looked just fine with the goggles on. I think you leapfrogged me on your progress by starting simple, with just a bead on flat stock. I also found that melting just a drop of filler rod on the base metal after it is well heated seems to accellerate the formation of a puddle. My rod motion in the puddle was much more back and forth along the axis of the weld than side to side across it. Going more side to side had the rod (coathanger!) getting stuck all the time. When I didn't need as much fill I just sort of dipped it and scratched it through the puddle and got a few fairly nice looking beads.

Somebody sent me the following url and I wish I could remember who... somehow the email got deleted but I have douwnloaded 3 chapters so far: the one on general introduction to welding, the one on gas cutting, and the one on gas welding. However, I tried to download the pay-for-it complete document in PDF and never got a password. Kinda ticked about that. But it is a very easy to understand and very detailed tutorial.

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Reply to
putyourspamhere2000

Thanks for the input. I did some more practice tonight and will be posting a few more questions.

Barry

Reply to
BP

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