Good oxy/acetylene welding tutorial?

[Stuggi]

I've been looking at video's on the net and yesterday I welded up some 6 mm steel rods into a poker just to try out welding with the gas torch, but now I'm a but stuck as the welds didn't look that pretty to me, and they seem to have oxide included in them. Could someone give me links to some kind of tutorial or give me some pointers on how to do "proper" welds with it?

 

[pedrobedro]

You need a neutral flame for welding steel. The flame is the important part, once you get that right you can concentrate on melting the metal and sticking bits together. An oxidising flame will burn the metal instead of melting it.Pictures here.

 

[chap]

You need to get the pressures right for the nozzle that your using (this was the mistake i was making). Really the pressures are right at the lower end of the scale.

If you're handy with the tig, then i find the action very similar (once you've got the torch setup right).
Also, as mentioned, you needd to use a neutral flame.

 

[eil]

I found it a lot better with two stage regulators as well.

 

[Stuggi]

Two-stage regulators?

One thing I've noticed is that if I set a neutral flame from the start, it will sort of "drift" into either a carbonizing or oxidizing flame (can not remember at the moment) after a little while, and I'll have to stop and adjust the mix again. Is this due to the nozzle heating up or what?

And no, I've never welded with a tig, so I'm a bit lost with the filler rod thingy. I remember hearing from somewhere that one should aim for fusion-welding the material firsthand and then only add filler rod if necessary, but this might all be BS...
Are there any specific motions or techniques I should use with the filler rod when doing different welds, or should it be done by feel?

 

[eil]

Yes two stage as opposed to single stage regs to give you a more stable flame.

 

[runnach]

And no, I've never welded with a tig, so I'm a bit lost with the filler rod thingy. I remember hearing from somewhere that one should aim for fusion-welding the material firsthand and then only add filler rod if necessary, but this might all be BS...
Are there any specific motions or techniques I should use with the filler rod when doing different welds, or should it be done by feel?

Nothing wrong to practice just fusing material together eg; 150x50x3mm steel sheet, clamp both pieces in vice, now fuse around all the edges, slight weave to make sure all the edges are washed in, then progress on to various joints using filler wire.

No technique really, once you have a feel and eye to what is going on, the rest will fall into place, I should add, torch angle around 70 degree, rod angle 20 degree, giving you an inclusive angle of 90 degree.

HTH?

 

[Stuggi]

Okay, cool, that 70/20 stuff is all new to me so nice! I've also been reading some old army textbooks on welding where they give all the dimensions for when to do a double V joint and so forth, so I guess I'll just give it a try.

 

[Bsmith]

A flame with just a little bit more oxygen (oxidising slightly) is better for brazing with O/A. Can't remember why though, its just habit with me now. Brian (",).