O-A Beginners Question

By Safari Date 03-20-2005 18:40

I am trying to practice and learn how to make and control a weld puddle on a piece of 3/16 plate. I am using a #4 nozzle, 4 P.S.I. Acetylene/4 P.S.I. Oxygen But am confused as to whats happening and what I should be looking for.

I think I have a neutral flame but am not really sure. The flame starts out yellow, I add oxygen (flame turns white), add more Oxygen (flame gets two cones, a long light blue one surrounds a darker blue one close to the tip), add more Oxygen to create one blue cone at the tip about 1/2 inch long.

At this point I notice the torch is hissing quite a bit. I hover on the plate with the tip about 1/8" from the work piece waiting for a puddle to form. The plate gets red in about 5-10 seconds (just like the book says). I keep waiting for quite a long time but it takes about 2-3 minutes to form a puddle. At times I get frustrated at the wait and bring the tip close to the plate. Then I get a "pop" at the tip! So I try to avoid that.

Am I doing something wrong? should it take this long for the puddle to form?

Also, how long should I leave the rod in the puddle when I dip it. Is the rod supposed to melt instantly? Mine doesn't and I have to point the tip at the rod even though it's in ( what I think) is the puddle.
Any help would be appreciated. Thanks

By burninbriar (*)

Date 03-23-2005 03:49

You may need more acetaine preasure.You should be able to open the valve until the flame stops smokeing and jumps away from the tip.Then close it until the flame just comes back.Also make sure the tip is clean by useing a tip cleaner.If that does not work try a #5.Nothing is an absolute.

By billvanderhoof (****)

Date 03-23-2005 08:29

It sounds as if you are adjusting the flame mixture correctly. If the torch pops easily you need more of everything (see above response for good torch lighting advice). If the metal won't melt you also need more of everything and perhaps a larger tip will be required to deliver it. If you hold the rod close to the flame when it isn't being dipped it will get preheated and then will melt more quickly when you dip it. I don't leave it in the puddle for long, Just kind of brush it through the puddle. It sounds like your main problem is not enough heat.
Bill

By sanglebrandt Date 03-24-2005 19:54

OK. The flame you are getting is an oxidizing flame. Too much oxygen. You want the dark blue flame by the tip, and the light blue one around that. Adjust your oxygen until it goes from 3 colors of blue, to where it just turns into two.

3/16" plate is pretty thick for OAW. But, a #4 tip should be fine. I usually go with 5-6 lbs for both oxygen and acetylene. Keep the dark blue part of your flame about 1/8" away from the metal.

If it keeps popping, turn on both your oxy and acetylene, light it, and make sure your pressure stays constant, your acetylene may be slowly dropping. If it is, try opening your valve a little bit more, but no more than about 1 turn.

By Safari Date 03-25-2005 01:44

Thank you guys,---------I appreciate the advice. I'm having a ball learning!

By Northweldor (***)

Date 03-26-2005 18:20

Safari:

Back in the” old days”, before the widespread use of check valves and flashback arrestors, beginners were always taught to balance gases. This is a procedure I still use today, not only because of safety, but because it is a good way to check on the current condition of your equipment, and guarantees the correct setting with any tip size or regulator gauge peculiarity. With a little practice, it only takes a minute, and accurately gives you the proper setting with any make of equipment, with the max. and min. of the heat range of any tip. The instructions I usually give an OAW beginner are below.

With both bottles on, and regulator adjusting screws turned out (“off” position), turn the acetylene torch valve wide-open (3 half turns is usually enough). Then, turn your acetylene regulator adjusting screw in until gas starts to flow and light the torch. Continue to turn the adjusting screw in until the flame just blows away from the tip, then back off the screw until the flame just returns to the tip. Your acetylene pressure is now set for that tip.

Then , open the oxygen torch valve wide-open (3 half turns) and slowly begin to turn your oxygen regulator adjusting screw in until you you have a blue feather extending from a blue cone at the tip. Continue to add oxygen until the feather just disappears into the inner cone, giving you a neutral flame. You now have the torch set for maximum heat for that tip. (Wiggle both torch valves at this point to make sure you have them wide-open: if you do, the flame will not change)

Finally, turn your oxygen torch valve off. Then, close your acetylene torch valve until the yellow flame starts to produce smoke, and immediately open it just so it is not smoking. Slowly open your oxygen torch valve until you again have a neutral flame , and you now have the minimum flame you can use on that tip without backfires.

This seems like a lot of trouble, but only takes 1-2 minute with practice and only needs to be done once each session, unless tips or regulator settings are changed. Also, note that at no point are you depending on or even looking at regulator gauges, which can be very unreliable when abused. This method will work with all standard OA equipment for welding.

You will use less gas, and have faster results, if you switch to 16ga. or 1/8” material for practice.

Good Luck!

By burninbriar (*)

Date 03-28-2005 04:11

Ilearned to use the meathod you described when useing guageless regulators and now thats the only meathod I use.It really works well and like you mentioned,its fool proof.

By Safari Date 03-30-2005 00:50

Northweldor,--------Thanks so much!!!, I will practice this proceedure and try to get it down. Your right, I have been going thru the gases real quickly. Maybe this method will work. Again, thank you for this information.