horizontal welding

[aidank]

hi all am fairly new to arc welding and recently done a 10 week night course, got the hang of welding steel horizontally from the course without too much bother, can produce good welds from this too

was trying welding 2" piping today, was cutting a slit in it 99% of the way with the angle grinder and then fill the gap, kept hitting "soft spots" in it

was trying to fill the split using a "spiral weave" technique if you know what I mean as instructor told us when doing the course

now my question is what is the best method of filling cracks like this when working horizontally about 3.5-4mm thick?

pipe was about 2.5mm thick and I had AC welder set about 120-130AMPS, however would kept blowing holes

any bright ideas,? good videos/dvds/ books on the net for beginners? I felt that I needed all the power of 130amps to get some good penetration, howver when I hit a soft spot and tried to fill the holes by going around the edges some holes tend to get bigger and bigger rather than filling as I hoped

 

[snowcat]

Have a look at flange jockeys posts in the arc and the TIG sections for some pointers, usual technique is to root then add fill/hotpass as required, pipes complex because you have to open or close the arc length to compensate for continually changing angle, as well your normally working with an open root which is knife edge stuff, as your cheesing the key hole, Iv welded a fair bit of pipe in me time, but I'm no expert most is in lose Assembly's and manipulated on the bench, 2" is a very hard size to start with, Id always have the TIG out for a small pipe like that........

As said have a scroll through F/Js posts there give you some ware to start at.....

 

[Drains]

Aidank - 2.5mm thick material and 120-130 amps is asking for trouble! I assume that was with 6013 3.2mm rods. If so, go down to 2.5mm rods, and drop the current to 90A or less, depending on your position, and rod manufacturers specs.

If you wern't getting pen on those amps then your prep was wrong (how wide was the slit?), or, as I say, wrong rod for the job.

 

[Feet 'n Inches]

I'd go along with a 2.5 rod for that thickness. You could also try no prep (i.e. the cut, square faces) but leave a gap of around 2.5mm. A bit of trial and error with the gap and the amps, and, of course, practice should see good penetration fairly soon.