O-A cutting torch ????

[CTjeepnut]

What am I doing wrong?
Slag keeps filling in behind the cut,
End up cutting a lot of it twice,
1/4" plate, 0 tip, O at 40, A at 7,
Holding torch perpendicular, about 1/4" above piece,
When I worked at the shipyard the burners never had that problem,
What's wrong?

TIA
CTjeepnut

[mudtoy67]

Any pics? Maybe try angling the tip toward the direction of the cut. I normally don't cut perpendicular unless the material is really thin, like 1/16". Also might try to travel just a little slower.

[Gordon]

For me the trick to not getting a lot of slag is to cut as fast as you can, and still cut all the way through. also too rich of a mixture will give more slag, you might try adjusting the preheat flame down a little.

at the ship yard they usually have a set up using 3 hoses one for the low pressure oxygen and one for the high pressure cutting oxygen, and obviously an acytelene one. This lets them tune things so they get a really clean cut, and those guys are good, cause if they don't get a clean cut then they get to grind all day.

As far as pressures and tip sizes I look on the chart every time and do what it says. I don't know if your numbers correspond to the chart or not.

[Broncoo]

A 0 or 00 tip with 20-25oxy and 3-5acetylene
check here
http://ukiahoxygencompany.com/victor.htm

and slow down a bit your probably not cutting thru all the way and the slag is just puddling in the kerf

runnin 90* to the plate is fine but you could push into the cut with metal that thin

[CTjeepnut]

Thanks,
I've got more burning to do today,
Will try it different ways,

CTjeepnut

[madmark]

jeepnut
I was a welder in one of the biggest machineshops in southern In for 5 years.Try setting your pre heat by sound.It should just barley sound like a light breeze.If you set it this way you will have to hold the torch very still at the start of your cut for what seems like an eternity,as the edge starts to turn orange,dont wait for a puddle to form.It will take some getting used to,but if your pre heat is set right ,the cut will look like it was made by a saw.Try this method,practice on some scrap till you see what I mean.The first 10 or 15 tries you will hit the ox and it wont cut,dont trun up the pre heat,just wait longer before you hit the ox.
Hope this helps!
Also if you are making streight cuts use a bar clamped to the piece you are cutting and just slide the tip along the bar.

[Foxfab]

try pre-heating the cut also before you actually cut.

[CrustyJeep]

Who cares about the pre-heat flame? If it's hot enough to start a cut, then good enough. It's all about the cutting flame. Set that sucker just a tad oxydizing. Usually if you set the pre-heat flame neutral, the cut flame will go heavy carbonizing, and that will fuck a cut up like nothing else. Remember, oxydizing = clean cut, carbonizing = a slaggy mess.

You could probly stand to turn your oxy pressure down some too. Try somewhere between 20 and 30. And angle the torch into the cut a few degrees.

Oh, and go faster. Too slow always makes more slag. If you outrun the cut, you've gone too fast by only a small amount. You're not melting the steel, you're burning it. If you linger and actually do melt the steel, that's when your problems start.